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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #1 (Edited)
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Also available in Word Doc form on my Google Drive for those who prefer it AND in case VWVortex makes old posts un-editable which would make properly updating my build thread impossible (already happened to my build thread on the Passat World forum). If that happens I will stop updating the VWVortex threads BUT will continue updating the Word Doc version in the link below. With pictures imbedded, the Google Doc version is too large to view in Google "preview" mode so you need to download it

Google Doc / Word Doc Format Build Thread:
https://drive.google.com/open?id=1V8BucTtzSt_ggjMMnx9RlahpCfS0eX2m

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Instagram: @track_rat_passat
YouTube Channel: https://www.youtube.com/channel/UChT0LKYGGW2-t54PIpMuVUQ?view_as=subscriber



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Preface

I purchased my B6 completely stock, with 50K miles on it, in Summer 2014. I began this build thread in Winter 2018 on the heels of completing my Big Turbo build (Summer 2018). I did quite a lot in those interim 4 years and a large chunk of this build thread is devoted to retroactively covering that. However, this highlights an inherent problem with that retroactive chunk of the build thread… I hadn’t planned to make a build thread. So I don’t have pics for a lot of stuff I should, nor do I have many mid-install/DIY pics, and frankly even my timeline for when I did stuff throughout those 4 years is probably not totally accurate. So you won’t get to follow the progress as it goes from the ground up like a lot of build threads, which is something I sincerely regret, but from here onward you will because now that the build thread is here I plan to go forward updating it and treating it like your typical build thread.

HOWEVER, I should make it perfectly clear up-front that this is NOT your typical build thread. If “build thread” were a genre of its own I’d have to classify this as something else because while it is a build thread at heart it may also read at times as a “review thread” and at other times as sort of a history or retelling of the events and decisions I made with the car. The bulk of this build thread is in a more detailed narrative and chronological format. I will go into significant depth as to why I chose the mods/parts I chose, based on research and, in some cases, getting lots of hands-on exposure to the mod/part selections other enthusiasts made for their cars in order to inform my decisions even more. I will also at times possibly go into depth about even more mundane things I did with the car. The idea is that bringing up anything and everything opens up opportunities to educate readers or spawn questions on, well, anything and everything… I like to be comprehensive and I don’t want to assume any particular level of knowledge of any given reader. I recognize that these stylistic choices are not to everyone’s taste and that it means the build thread will be very lengthy, possibly dry or “fluffy” at times, etc. and that this may even ostracize some readers… That’s fine because my primary goal is always to educate/help, and my secondary goal of the thread is as sort of documentation of mine and my car’s journey for myself. It is my hope that anyone who actually has the interest to make it through this novella of a build thread will walk away very informed and with a clear idea how to go about their own builds.




Table of Contents (for major posts)

***Note: A majority of the posts mentioned below are retrospective posts on work completed long before I began this build thread. I was able to keep most of them consecutive because I reserved those posts right away when I started the thread… Unfortunately I didn’t have the foresight to reserve enough posts so some posts covering work that came AFTER I began this build thread are/will be scattered throughout the thread but their post numbers will be tracked in the below Table of Contents… Topics for which I go into extra-thorough detail, more than usual even, will be noted with BOLD text below


Post #1 (this post) ---------------------------------------------------- Factory specs vs. modded specs; full mod list; potential future mods section; external resources; changelog (thread update history)

Post #2 ---------------------------------------------------------------- Intro to car and what to expect from this thread; first pics totally stock

Post #3 ---------------------------------------------------------------- First “mod”; some maintenance tips; new wheels; new grille; tire choices/info

Post #4 ---------------------------------------------------------------- Software tuning (“shelf“ and “custom”); cold air intakes; PCV system; and catch cans; new wheels; shifter upgrades; maintenance tips

Post #5 ---------------------------------------------------------------- Full turboback exhaust; HPFP upgrade; stiffer engine/trans mounts

Post #6 ---------------------------------------------------------------- Clutch kits/parts; Raceseng shift knob; P3Cars multi-gauge; additional maintenance tips

Post #7 ---------------------------------------------------------------- Big brake (BBK) upgrades; pads; rotors; brake fluids

Post #8 ---------------------------------------------------------------- Suspension items, including: struts/shocks/springs; strut mounts; end links; sway bars; control arm bushings; subframe mounts/mods

Post #9 ---------------------------------------------------------------- Lots of miscellaneous mods/parts over the years that don’t fit a particular chronology

Post #10 -------------------------------------------------------------- Miscellaneous maintenance and troubleshooting/diagnosis tips from over the years that don’t fit a particular chronology; ALSO, a couple sort-of DIY guides

Post #11 -------------------------------------------------------------- Suspension alignment; race pads/track tires; REAR suspension modifications; mount modifications made for a more track-oriented car

Post #12 -------------------------------------------------------------- Turbo upgrade considerations; turbo wastegates/boost control functionality; some matters of tuning

Post #13 -------------------------------------------------------------- Stock engine limitations; Fluidampr pulley; fueling upgrades; intake manifolds upgrades

Post #15 -------------------------------------------------------------- Air cooling (w/ upgraded intercoolers) and water cooling (w/ upgraded radiators)


Post #32 --------------------------------------------------------------- Feedback on Grams Performance 70mm throttle body and info on ECU air/fuel ratio calcs and strategies that pertain throttle body upgrades




Factory Specs

***Note: In addition to just presenting some baseline factory specs, some of the below are mentioned to show how the B6 Passat is actually moderately sized as Sedans/Saloons go (at least in the USA) and not all that much larger/heavier than the GTI of the same generation.


Make: Volkswagen (obviously)
Year/Model: 2007 B6 Passat
Engine/code: 2.0T FSI/BPY
Transmission/code: FWD 6-speed manual trans/02M
Horsepower: 200chp
Torque: 207ctq (ft-lbs) OR 280ctq (Nm)
Tachometer redline: 6500RPMs
Curb-weight: 3305 lbs. / 1499kg. (compared to 3161 lbs. / 1434kg. for 6-speed Mk5 FSI GTI)
Power/weight ratio: 0.060 (compared to 0.063 for 6-speed Mk5 FSI GTI)
Length: 15’ 6” / 4.7m (compared to 13’ 8” / 4.2m for Mk5 FSI GTI)
Height: 4’ 10” / 1.47m (same as Mk5 GTI)
Width: ~ 6’ / 1.8m (compared to 5’ 9” / 1.75m for Mk5 FSI GTI)
Drag coefficient: 0.28 Cd. (better than 0.32 Cd. for Mk5 FSI GTI)
Chassis torsional rigidity/stiffness: 32400 Nm/degree (equivalent to a Porsche 911 (977), significantly better than the 25000 Nm/degree of the Mk5 GTI)
0-60mph: 6.6 seconds (compared to 6.1 seconds for Mk5 FSI GTI)
Quarter-mile time/trap speed: 14.8 seconds / trap speed unknown but likely a bit under 100mph (compared to 14.6 seconds for Mk5 FSI GTI and likely trap speed of a bit under or right at 100mph)




Modified Specs

***Note: Below are notable changes to my car's specs that differ from above factory specs. Regarding dyno results, 0-60mph, and quarter-mile stats… I am interested but not obsessed with these figures. I’m much more interested in the drive-ability and well-roundedness of my tune than I am with peak HP/TQ figures just like I’m more interested in not breaking my car than I am in launching my car umpteen times to get excellent 0-60 and quarter-mile stats. I’m not very into aggressively launching my car and I’m not hunting fame for these stats, just enough runs to satisfy my curiosity (and somewhat justify my expenses to myself haha).


Horsepower: ~420chp / 380whp (pending dyno results after I've stopped making changes to my setup)
Torque: ~385ctq / 365wtq (ft-lbs) OR ~520ctq / 495wtq (Nm) - (pending dyno results after I've stopped making changes to my setup)
Tachometer redline: 7400RPMs (w/ custom tuning software)
Curb-weight: 3200 lbs. / 1451kg (105 lbs. / 48kg lighter than factory spec)
Power/weight ratio: 0.131 (if above power figure anticipations are correct)
0-60mph: Of only a few intentionally conservative 0-60 runs (timed accurately by my P3Cars gauge) each was right around 4.3 seconds without building boost or dumping the clutch and with loss of traction on 400AA A rated all-season tires
(suspect 0-60 of 4 seconds or slightly less is easily achievable with aggressive launch and 200AA A or better rated tires)
Quarter-mile time/trap speed: at current power levels on a prepped surface I'm confident I could get a slip somewhere in the high 11-second range or low 12-second range (at worst) with trap speed of 120mph or better, but I'm not going to try until I've built my motor, it's not worth it; I prefer race track driving to drag strip runs anyway. With built motor and maximizing my setups potential, low 11s w/ 120-130mph trap speed is virtually guaranteed.




Modifications List

***Note: I’ll maintain a current list of mods and notable OEM upgrade parts here. This list will always reflect what is currently on the car as the go-to accurate list. Any parts that I chose to replace with another brand/design will be detailed in the thread itself.


Engine:

United Motorsport custom tuning software
Advanced Tuning Products (ATP) GEN 2 stock-location GTX2867R turbocharger kit w/ 22PSI base-pressure wastegate actuator for internal wastegate
Go Fast Bits DV+ (w/ NO piston main spring installed) relocated via custom-machined intake-to-turbo inlet junction pipe
OEM N75 boost control solenoid relocated to a custom-machined bracket bolted to top of engine mount w/ vac lines connected to custom turbo inlet junction pipe
Integrated Engineering high performance intake manifold
Grams Performance 70mm throttle body
BSH Speedshop throttle body pipe
Treadstone Performance TR8 front-mount intercooler (w/ custom 2.5” aluminum piping)
o Neuspeed stock-location intercooler delete brackets (custom-modified to accommodate additional bracketry for external oil cooler mounting)
o Wagner Tuning stock-location performance intercooler (removed as of Fall, 2019)
Mishimoto full-aluminum performance radiator (custom-modified w/ standard hose-barb inlet/outlet ends welded on)
Forge Motorsport cold air intake (filter enclosure painted gloss black)
o Custom bracket to support Forge CAI (prevents contact w/ master cylinder on road bumps)
o Audi Performance and Racing (APR) carbonio cold air intake (removed as of Fall, 2014)
BSH Speedshop intake heatshield (mounted to rear of engine between CAI and exhaust manifold)
Billy Boat Exhaust 3” full turboback exhaust system
Audi RS4 low-pressure fuel pump (modified to fit)
Audi Performance and Racing (APR) high-pressure fuel pump
Tork Motorsports 155-bar fuel pressure relief valve
VW Golf R fuel injectors
BAR-TEK Motorsport internally thermostatted oil cooler flange w/ -6 AN braided nylon hoses to 19-row air-cooled oil cooler (custom mounted directly behind grille for open airflow)
VW Golf R 3-bar manifold absolute pressure (MAP) sensor
Audi R8 ignition coil packs
NGK BKR8E (gapped @ 0.024)
o NGK BKR7E (no longer used since upgrading to bigger turbo setup, Summer 2018)
Integrated Engineering billet aluminum/black anodized valve cover
Custom positive crankcase ventilation to atmosphere (via -10 AN braided nylon hoses routed to VTA filter fastened at front of exhaust tunnel behind subframe)
o Integrated Engineering catch can system (removed as of Fall, 2019)
o BSH Speedshop competition catch can (removed as of Fall, 2017)
Fluidampr crankshaft harmonic balancer

OEM air condition deleted, including condenser (to improve airflow to radiator), compressor, and all pressure lines (w/ custom block-off plate at firewall entry)
OEM balance shaft assembly deleted from oil pump (eliminates a major risk of oil pump seizure at high revs and reduces rotation weight on crankshaft for faster rev/small increase in power)

Liqui Moly Leichtlauf fully synthetic 5W-40 (for general use - changed at ~5K miles OR 4-month intervals)
Redline fully synthetic ester-based 5W-50 (for warm weather & track use - changed at more frequent, as-needed intervals)
ECS Tuning polished billet aluminum oil filter housing
New South Performance pass-through oil pan drain bolt (to accommodate temperature sensor for oil temp gauge)
o Dimple engine oil drain pan magnetic plug (removed as of Fall, 2019)
Usually Sideways Rally Team (USRT) oil pressure sender adapter (allows use of oil pressure sender for oil pressure gauge while retaining factory low-pressure sender/switch
ECS Tuning black anodized oil dipstick
Porsche 911 aluminum coolant reservoir cap


Transmission:

HS Tuning RSR clutch kit w/ Golf R dual mass flywheel
USP Motorsports stainless steel clutch line
ECS Tuning modified clutch bleeder block
Audi Performance and Racing (APR) adjustable short shifter kit (set to 100% shorter front/back throw & ~75% shorter side-to-side throw)
Audi Performance and Racing (APR) solid shifter cable bracket
ECS Tuning solid shifter cable bushings

Redline MTL (75W-80 GL4) gear oil
Dimple gearbox magnetic plug


Suspension/subframe/mounts:

KMD Tuning front subframe brace (mounted w/ ARP bolts)
Stern rear subframe brace (painted gloss black)
Ultra Racing strut brace (painted gloss black)
Ultra Racing mid-chassis/underbody brace
H&R 26mm front sway bar (set to soft = ~130% stiffer than stock)
H&R 24mm rear sway bar (set to firm = ~270% stiffer than stock)
SuperPro front/rear adjustable end links (installed at curb weight!.. details in thread)
034 Motorsports street density (60A) front strut mounts
Koni “Yellow” adjustable sport struts/shocks (front and rear set 1/8-turn from full-stiff)
Vogtland sport springs (1.6” lower)
Torque Solution track density (75A) motor/trans mounts
o 034 Motorsports street density (60A) motor/trans mounts (removed as of late Spring, 2018)
Custom-machined subframe dogbone pendulum w/ track density (75A) polyurethane bushing
VWR/Racingline subframe dogbone mounts
TyrolSport front/rear subframe rigid locking collars + ARP bolts
OEM B6 Passat lightweight aluminum front lower control arms (LCAs)
o SuperPro front LCA race density (95A) polyurethane bushings
o SuperPro front LCA street density (80A) polyurethane bushings (removed Summer, 2019)
Powerflex race density (90A) rear LCA polyurethane bushings (arms & entire rear subframe painted gloss black)
034 Motorsport adjustable rear upper control arms w/ 90A polyurethane bushings
Powerflex race density (90A) rear trailing arm polyurethane bushings (arms & spindle painted gloss black)
034 Motorsport adjustable rear toe arms w/ 90A polyurethane bushings
o Spulen adjustable rear toe arms w/ pillow-ball bearings (removed as of Summer, 2018)


Braking:

TyrolSport master cylinder brace (modified to fit w/ APR short shifter kit)
StopTech ST-40 front “big brake” kit, including:
o StopTech ST-40 front brake calipers w/ custom powder-coating
o StopTech 2-piece slotted AeroRotors (328mm x 28mm)
o StopTech stainless steel brake lines
o StopTech sport front brake pads for ST-40 BBK (stopped using as of Fall, 2018)
o Porterfield R4-S front brake pads for ST-40 BBK (used for performance street/autocross)
o Porterfield R4 front race brake pads for ST-40BBK (used for track ONLY)
OEM rear brake setup (painted in high-temp gloss black)
o StopTech slotted rear rotors (OE size)
o Adam's slotted rear rotors (OE size - removed as of Fall, 2018)
o Porterfield R4-S rear brake pads (used for performance street/autocross)
o Porterfield R4 rear race brake pads (used for track ONLY)

ATE Typ200 brake fluid (used outside of track season)
Castrol SRF racing brake fluid (used during track season)


Exterior:

ECS Tuning front grille replacement (painted gloss black to match body)
Depo Smoked black front bumper side markers/indicators (now w/ orange bulbs inside to retain function when using turn signal)


Interior:

Raceseng "Slammer" polished stainless steel shift knob
P3Cars VIDI multi-gauge in analogue vacuum/boost reading configuration (w/ blue and red lighting to match OEM interior lighting)
New South Performance oil temperature gauge mounted in steering wheel column pod (w/ blue and red lighting to match OEM interior lighting) and temp sensor in oil pan
New South Performance oil pressure gauge mounted in steering wheel column pod (w/ blue and red lighting to match OEM interior lighting) and pressure sensor sharing same location as factory low-pressure switch/sender
Vantrue N2 front/rear dash cam (mounted to rear-view mirror stalk & stealthily wired to dash-mounted parking-mode on/off switch + power management system)
GoPro HERO7 Silver camera mounted to helmet for cockpit view during track racing sessions (onboard GPS allows video overlays for speed, track layout, and more)
o GoPro HERO4 Silver camera mounted to top of rear seat assembly for rear view during track racing sessions
o GoPro HERO4 Session camera mounted to steering column for instrument cluster view during track racing sessions
Pioneer X6600BT single-din, bluetooth-enabled headunit (w/ blue and red lighting theme to match OEM B6 Passat dash lighting)
Johnson Window Films 35% window tint all-around (excluding front windshield)
WeatherTech sun shade
WeatherTech black floor and trunk liners
The Bracketeer fire extinguisher mounting bracket (under front of driver’s seat)


Wheels/tires:

Neuspeed 18x9" RSe11R hyper silver wheels - 45mm offset - 19lbs. each (for track tires)
o Hankook 255/35R18 Ventus R-S4 extreme performance summer tires (for track and Summer-only street use)
Motegi Racing 18x8.5" MR140 hyper silver wheels - 45mm offset - 19lbs. each (for street tires)
o BFGoodrich 255/35R18 Sport Comp 2 ultra high-performance A/S tires (for general street use outside of Summer)
Enkei 18x8” M52 “Hyperblack” (dark silver) wheels - 45mm offset - 21lbs. each (previously for street tires from 2017 to early 2020 - sold in favor of wider wheel/tire set)
o BFGoodrich 225/40R18 Sport Comp 2 ultra high-performance A/S tires (previously used as street tire until Enkeis sold in early 2020)
o ECS Tuning 10mm (front) & 15mm (rear) black anodized, hub-centric wheels spacers (previously used ONLY with Enkei M52/BFG SC2 wheel/tire set for street until early 2020)
OEM 16x7" Catalunya silver wheels (previously used for Winter tires until 2017 - have used my Silverado pickup for Winter driving since then)
o Dunlop 215/60R16 Wintersport 3D performance winter tires (no longer used - have not used car in snowy/salty conditions since before 2017)




What’s Next?

***Note: The below is a tentative (and probably very optimistic) plan of mods that I would like to do at some point in the future, sorted by time/opportunity as opposed to category like above; some are much more likely than others (i.e the cosmetic mods are very unlikely because I value function over form without hesitation).


Imminent - Early 2020:

• Install WMI w/ post-turbo + post-intercooler + direct port injection nozzles for COOLING only, NOT to tune for additional power (this setup will allow dramatically lower intake air temps, combustion temps, exhaust gas temps, and thus a happier engine/turbo)


Late 2020:

• Consider replacing ATP exhaust manifold with tubular exhaust manifold
o Apply Swaintech thermal coating to either manifold (and downpipe)
• Switch to Tial 38mm MVS external wastegate setup
o Explore simulated boost-by-gear tuning parameters using VSS and RPM signals as inputs (since manual trans gives no electronic reference for currently selected gear)


If/when trans-related repairs needed:

• South Bend stage 3 w/ SMF (friction disc option pending robustness of RSR at track)
o If opting for endurance/race clutch, will consider SRE clutch options as alternative
• Wavetrac LSD (may consider a new/low-mileage trans swap first pending circumstances leading to timeliness of this upgrade)
o Have old or "new" trans cleaned and powder-coated (only if timing and price is right)
• OE steel shift forks (02M311549Q)
o Shift fork bronze sliders (SQS)
• 4th gear input shaft support (Darkside Dev)
• Gearbox reinforcement plate (Darskide Dev)
• Main shaft re-enforcements
• Differential rivets-to-bolts swap
• Upgraded syncros (if available – [ending research)
• AWD conversion from 4Motion B6 Passat (likely never, but one can dream…)


Pending assessment of stock motor longevity:

• Refresh & rebuild/upgrade engine & internals (rods/pistons/timing gear/main & rod bearings/main caps/ARP bolts & studs)
o Have block/head cleaned and powdercoated where possible
• Upgrade injectors OR add 5th port injector to intake manifold
• Upgrade LPF supply with auxiliary pump OR PM3 module to increase fueling output


Likely never (at least not until car is retired from track use):

• Duraflex, Rieger, Cupra R, or Votex lip spoiler
• Further grille/bumper & other body modifications
o R36 front bumper/grille, or VW hi-def RGT body kit, or RS4 body kit
• Fog lights (maybe, but only if they project clear lighting not yellowed lighting)
• Depo smoked factory style headlights modified w/ halo rings and LED strips
• R36 OEM taillights OR Depo smoked factory style taillights (if available)
o For either, perform Skyline taillight mod and taillight running condition changes
• SRS-Tec or other wider front/rear fenders to accommodate wider wheels




[RESOURCES] - Below are some self-study materials; technical materials in PDF format (hosted on my Google Drive), some random resource threads that I've either posted info in or found helpful over the years myself, and a link to another build thread for VERY well done Mk6 GTI track car owned by a good friend of mine

FSI Design & Function Manual: https://drive.google.com/open?id=0Bzeazv76x9MXUjF1a1FSUFJkdFE
FSI Technical Data & Specifications Book: https://drive.google.com/open?id=1igHOT69IsNg-oE3TTT09uh8D_X5ya9-u
STASIS Guide For Many Engine & Turbo Jobs: https://drive.google.com/open?id=0Bzeazv76x9MXdHN3VXd1UnJnZGc


Miscellaneous threads:
http://racetrackdriving.com/car-setup/track-alignment/
http://www.stoptech.com/technical-s...ias-and-performance-why-brake-balance-matters
http://www.uucmotorwerks.com/CLUTCH/
https://www.phoenixfriction.com/t-cl...explained.aspx
https://www.enginebasics.com/Advanced Engine Tuning/Intercooler Efficency Test .html
https://www.golfmk6.com/forums/showthread.php?t=66367
https://forums.vwvortex.com/showthread.php?8819306-Let-s-talk-brakes
https://www.golfmkv.com/forums/showthread.php?t=173203
https://forums.vwvortex.com/showthread.php?8774745-Sway-Bar-End-Link-Question
https://forums.vwvortex.com/showthread.php?8980465-Koni-Yellow-settings-MK6-GLi
https://forums.vwvortex.com/showthread.php?8747154-Metallic-whine
https://forums.vwvortex.com/showthr...-WOT-only-Seemingly-NO-boost-loss-or-vac-leak!
https://forums.vwvortex.com/showthread.php?8856297-Wastegate-Behavior
https://forums.vwvortex.com/showthread.php?9283713-Upgrade-internal-wastegate
https://forums.vwvortex.com/showthread.php?9275547-2013-GLI-Big-Turbo-Eurodyne-Maestro-7
https://forums.vwvortex.com/showthread.php?8846737-How-much-hp-can-stock-block-hold
https://forums.vwvortex.com/showthread.php?8771033-What-kind-of-oil-for-a-2007-Passat
https://www.passatworld.com/forums/...97-2009-vw-passat-2-0t-sedan-reliability.html
https://forums.vwvortex.com/showthread.php?8828393-Average-life-expectancy-of-2-0T-FSI
https://forums.vwvortex.com/showthr...cing-oil-filter-housing-cooler-on-Mk5-GTI-FSI
https://forums.vwvortex.com/showthread.php?9123721-GTI-2-0-TSI-Air-Conditioner-Issue-maybe
https://forums.vwvortex.com/showthread.php?8725273-MK5-Brake-Hissing
https://forums.vwvortex.com/showthread.php?8747154-Metallic-whine


Friends Mk6 GTI Track Car Build Thread:
https://www.golfmk6.com/forums/showthread.php?t=115417




[Build Thread Changelog]

- 11/18/18: Original build thread posts
- 11/24/18: Suspension/subframe post
- 11/26/18: Added 20+ new pics for more eye-candy
- 12/02/18: Added details regarding catch cans vs. block-off plate-only setups
- 12/19/18: Significant additions to detail in clutch information/options
- 01/25/19: Added details regarding solving a noise issue you may develop when installing a catch can or block-off plate; added useful self-study and tech materials to the resources section
- 01/26/19: Added further detail to tuning subjects section
- 03/05/19: Added part additions for upcoming track season to mod list (post w/ details on these parts and installs will come later)
- 03/29/19: Significant additions to detail of brake section (primarily pad, rotor, and brake fluid selection info)
- 05/27/19: Re-organized and added details to mods list; additional details to tuning section; fixed some typos
- 06/02/19: Added new post with miscellaneous mods/parts installed over the years that don’t fit a particular chronology; also added table of contents for easier navigation
- 06/14/19: Added new post which contains maintenance and troubleshooting experiences/tips as well as a couple sort-of DIY guides
- 07/12/19: Added new post which covers a significant turning point for the objective of the car, primarily rear suspension work (lots of pics) and other stiffening mods for full track prep
- 07/16/19: Added new post which covers my experience/feedback on the Grams Performance 70mm throttle body and significant details about ECU fuel trim calculations and AFR info pertaining to the Grams TB operation
- 09/14/19: Added custom-machined subframe dogbone pendulum pictures/info to rear-suspension post; also made slight updates to mod list, introductory post, tuning discussion, and a couple other places
- 11/10/19: Fixed typos, formatting, and added some (probably) inconsequential details to a few posts
- 11/11/19: Cloned thread over to Google Docs and will maintain it as well, in case VWVortex removes the ability to edit old posts (which would ruin my ability to properly maintain it on VWVortex and drive me nuts)… already happened on Passat World forum
- 11/14/19: Added Instagram and YouTube Channel info to top of main post
- 12/07/19: Added new post which covers substantial info on turbo upgrade considerations, turbo wastegates and boost control functionality, and some matters of tuning
- 01/04/20: Merged post a couple earlier posts to shift all subsequent posts up one and make room for the 2 new posts coming up which should be kept together
- 01/05/20: Added 2 new posts which cover substantial info on stock engine limitations, Fluidampr pulley, fueling system upgrades, upgraded intake manifolds, upgraded intercoolers and radiators
- Next upcoming post: Prep for 2020 track season, including: full AC system delete, oil pump balance shaft delete, intercooler and radiator changes, external oil cooler system, oil temp and oil pressure gauges, switch from catch can to PCV vent-to-atmosphere setup, and several suspension/chassis braces
 

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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
Joined
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1,818 Posts
Discussion Starter #2 (Edited)
Intro/Background

Welcome to my build thread! For many, the title of my thread may already have you thinking to yourself how much an oxymoron it is to consider a Passat to be almost equal parts track car as it is comfy street car, or how foolish it is to spend the kind of money needed to develop a Passat to that point. Sure, a Passat may not be the most ideal model for pulling this double-duty, that’s fair, but it is my hope that this thread will show the merits of a well-sorted, tastefully modified Passat. While the B6 Passat does have some innate disadvantages in track performance areas – compared to the more popular GTI – most notably in its size/weight, you can see from the factory specs in my first post that the differences are not that drastic. Furthermore the B6 Passat has an ace up its sleeve; the chassis torsional rigidity is very very high, comparable to a Porsche 911 (997) and higher than many cars with much sportier pretensions. The purpose is for crash safety but this characteristic can absolutely be felt and taken advantage of for performance driving, particularly if the rest of the softness in the suspension – rubber bushings, hollow anti-roll bars, and other things that would supersede chassis flex – are taken care of first. I will not belabor any more technical details in this intro section but I brought that example up to demonstrate that there is more than meets the eye to the B6 Passat platform; considerations like chassis torsional rigidity are also examples of the kind of depth you can expect from my build thread. It is my hope that my build thread will show that the shortcomings of the B6 Passat in performance categories can be mostly overcome, whilst the multitude of attributes unique to the Passat make up the difference (and then some in my opinion). In essence, a thoroughly modified B6 Passat can strike a unique and well-rounded balance between being a sporty, responsive, and engaging vehicle to drive while also maintaining a far more spacious, comfortable, quieter, and higher quality interior as well as the advantage and appeal of being a rare breed to modify and a hilariously surprising sleeper.

If you’re not convinced, or if these thoughts didn’t even cross your mind – you’re just here to read a build thread – then, either way, you’re in luck because the heart of this build thread is INFORMATION. In all honesty, I’m mostly a dry, technical kind of guy so if you can tolerate that then you should be in for plenty of good info and considerations for your own build plans. And, PLEASE, feel free to ask any questions, I love answering questions even more than I love asking them. I’ve been a very active poster on VWVortex for just this reason, I always enjoy helping people out or just shooting the **** about cars.

I’ll start with a little background. In the summer of 2014 when my then current car, a hand-me-down 2000 Jetta GLS 5-speed, was beginning to show its age with 200K+ miles and poor maintenance history, I sold it for what I could. It was my first car, I had it for 6 years, and I still sometimes miss it a bit. I wonder what could have been if I actually knew a damn thing about working on and maintaining cars back then. I suspect it went on to last a good while longer as it were after I sold it, but had I kept it – and had I known what I know now – it’d definitely still be alive and well even to this day. But that’s just the thing: had I kept it, I most likely wouldn’t know what I know now about cars, I’d most likely still be totally inept. It was only after I sold that Jetta and bought my Passat that I took it upon myself to start learning to maintain it; partly in the interest of simply saving money but also partly because, even stock, it was a much more invigorating car to drive than the Jetta and I guess I wanted to form a bit more of a connection to it by working on it myself. Yeah maybe a little weird, but I know real car people totally get where I’m coming from on that last point.

So suffice to say, buying the Passat marked the start of a journey. It was a journey that started at ground zero for both of us because the Passat was totally stock and I didn’t know the first thing about cars. It was in starting to learn how to do even the simple stuff like oil changes, spark plugs, air filter, etc. that I became aware of the thriving VAG aftermarket and that, combined with the light nudging of a good friend and now fellow enthusiast, is what sent me off in the direction that brought my Passat and I to where we are now.




My First Detailing Job

But I’m already getting a little ahead of myself because the very first thing I did you my Passat was not mechanical at all. Yes, the very first thing I did was clean her up real good. She was already pretty clean but when I buy something new (to me) I usually get hit with the hardcore OCD so my new pride and joy just wasn’t clean enough (also the engine bay was filthy). Plus “clean looking” wasn’t enough for me, I wanted to make sure the paint was squeaky smooth (free of bonded contaminants) and well protected too so that meant I needed to do a full exterior detail, not just a wash. Unfortunately, I don’t have BEFORE pics, only AFTER pics…

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I think it turned out pretty damn well for a first time detailer. I did a lot of research beforehand on products and all the correct methodologies of detailing the right way and since I pick stuff up pretty quick, especially things that are very methodical and meticulous in nature, I got into detailing fast. Still love it. I’ll say this: I’ve tried just about all the major brands/products out there by now (as of time of writing in 2018) and while some of the more expensive products like AMMO, Adam’s, etc. are better than the affordable brands like Chemical Guys and Meguiar’s, they aren’t really better enough to justify more than double the price in most cases. There are a few specialty products you get from those upper-end brands that are worthwhile but for the main repertoire of detailing supplies CM and Meguiar’s have totally fine products that compare quite well. Honed techniques and methods in detailing is FAR more critical to good results than choosing between brands.

Oh and I also put in WeatherTech black floor and trunk liners!
 

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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #3 (Edited)
The First “Mod”

So, anyway, what was the first “mod” I did? An aftermarket headunit of course! The base model 2007 Passat 2.0T has a 6-CD cylinder style stereo/radio unit. Now it definitely beat my Jetta’s because the CD cylinder for the Jetta was in the trunk and the Passat’s could receive all 6 through the CD slot and stack them up internally buuuut meh. So I got a good Pioneer single-DIN headunit with Bluetooth/mic and smart phone compatibility, etc. No navigation or anything fancy, never really cared for that. Even for the extreme novice electrician that I was (and still am for the most part) the install was pretty simple. Bought the kit from Crutchfield. Just had to buy a CAN-BUS adapter in addition to the basic kit. I used the empty storage tray portion that fills in the rest of the double-DIN space to wire and attach the mic too instead of running it up to the sun visor or anything complicated. It works just fine where it is and points right at me.

I did, of course, change the accent lights on the buttons/faceplate to red and kept the color for text on the LED screen as blue, thus matching the factory red/blue interior lighting!

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Some Good Basic Maintenance Notes (Especially on the Topic of Oil Choice)

Also around this time I took care of some basic maintenance items; oil change with Mobil 1 0W-40 (I think I may have started taking samples for Blackstone lab analysis as early as this first oil change too), also spark plugs, air filter, cam follower, maybe N80 valve, etc. Basically most of the cheap and common FSI/BPY attention areas. Also checked to make sure I had a Sanden AC compressor instead of one of the other OE brands that were known to fail and literally frag inside your AC system/lines. I did these things preventatively and wasn’t overly concerned about this cars health at all; aside from some cosmetic areas I have yet to address, the car was clearly well maintained and cared for in the 50k miles it had been driven by previous owner.

Since I brought up oil above I’ll take this opportunity to point out that, over the years, I’ve done a considerable amount of research and experimentation with many top-notch VW 502.00 spec oils along with Blackstone lab analyses for all of them, multiple times each, and have arrived at what I believe to be a very well informed, validated, and complete understanding of the best oil options available for the FSI/TSI 2.0T motors. Rather than burden this already massive thread, I will just drop a link to a thread in which I have several posts on the subject. If you read all my posts in this thread you should be very well informed.

https://forums.vwvortex.com/showthread.php?8771033-What-kind-of-oil-for-a-2007-Passat




Some New Shoes and Rubber

After that point the very next thing I did was get some better rubber! My car came with the common factory all-season Michelin Primacy MXV4 in 215/55R16. That’s typical of Passat’s being that VW certainly isn’t targeting sporty or enthusiastic drivers with the Passat line. But either way 215/55R16 is very close to equivalent circumference to the 225/40R18 tires on factory 18” wheels so the size of tire I had on my Passat is just as much a function of the size of the wheel and the fact that VW doesn’t want to have different instrument clusters programmed for different speedo and odometer readings across their various models and factory wheel/tires sizes.

Anyway, those Michelins weren’t that bad for a Grand Touring style all-season with pretty hard compound but they were FAR from what a spirited driver wants so I ditched them a went for winter/summer configuration: Dunlop Wintersport 3D in 205/60R16 on my factory 16” alloys for winter and BFG Sport Comp 2 summer tires in 235/45R17 on a new set of 17” OEM Autobahn GTI wheels.
Around this same time I also got rid of the hideous badged grille. I bought the car in a state that requires front plates as well but don’t need it in PA so I got a badgeless black grille to bring a more aggressive look to the Passat.

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Thoughts/Experiences on the Winter Tires… And a Little Snowy-road Story

I got these Dunlop Wintersport 3D tires in a tall/narrow size as one should so they bite in snow more and are less prone to slide and, well there is no other way of saying it, they were absolutely knock-your-socks-off fantastic for their price. I have had some lackluster experience with Dunlop all-season and summer tires in the past (one set of which I had on briefly during ownership of this car but that I’m not even going to bring up again, that’s how bad they were) but these Wintersports were, according to reviews, about the best of what was in my budget at the time and they far exceeded my expectations. At first I was reserved in my winter snowy driving with these but very quickly came to trust them and pushed them more and more and more and I am pretty sure I still never really found the limit. Quite frankly there was one particular winter (the one right after I got these) that I was driving like a complete moron for the conditions and some might have thought I had a death-wish, but that’s how confident these tires made me and I never once had a close call with them. Still shouldn’t have been pushing my luck that way, but we all do stuff we shouldn’t from time to time. In one instance I was driving to work one wintery day on a seldom traveled backroad with nobody else on it at the time and I was running behind so I was driving very fast for the conditions. There was a good couple inches of fresh powder on the road, and more coming down during the drive, and I came upon a straight and fairly long section of the road and got up to about 70mph (yes I was being a moron in retrospect), I trusted the tires a lot already at this point. Well, I live in deer country and, you guessed it, a deer jumped out ahead of me at most 200ft. Instinctively I knew I had absolutely 0% chance of braking successfully in this case so I didn’t even bother. I don’t recall if I let off the throttle even or if I continued at my speed but, either way, I went for the dodge maneuver. I attempted to abruptly swerve around the deer, which required me to use the entirety of the fairly narrow 1-lane (each way) road I had and it was NOT a gradual swerve by any means, given the speed I was going and how close the deer was relative to the speed. I still figured I had a good chance of ending up in a tree this way too but it was my best shot. Of course, this whole event and all the thoughts I had happened inside less than a second and after that second had passed I had successfully dodged the deer completely, and returned to my lane unscathed and in COMPLETE AND UTTER AMAZEMENT that the tires didn’t even let me slide one bit. It was almost as if there was no snow at all despite the fact that there was a least 2 inches of fresh powder. It’s possible somebody up there was just looking out for my dumb ass but you never know; the only thing I can definitively point to is those tires. So, considering their exceptional price tag on Tire Rack, I’d get them every time. I can’t see those crazy expensive Blizzacks being much better to be totally honest.


Thoughts/Experiences on the Summer Tires

I got these BFG Sport Comp 2 summer tires 235/45R17, factory equivalent size for 17” wheels. They are a tad beefy for a summer set but the roads in PA are atrocious and, frankly, I don’t like the really low profile or stretched look. Even at this size, just slightly tall for a performance setup, these tires absolutely kill it for their price. BFG knocks it out of the park with this tire and especially the price. Are there better summer tires? Sure, but are their better summer tires for the price? Not really. And that’s not just according to me, that’s according to independent testers and professional testing from companies like Tire Rack… I always do my research. The only tire that I think is known to stand up to these Sport Comp 2 and for actually a bit less is the Firestone Firehawk Indy 500. I cannot personally comment on them but I may in the near future if I get a set to try out. Anyway, I don’t have any crazy stories for these BFG tires like I did for the Dunlop winters but they are hands-down a fantastic tire for the price and I’ve still gotten away with some stupid driving with them. If I had to make one complaint about them it would be this: they don’t talk to you that much. They don’t give you much warning before traction loss is imminent. So if you’re still experimenting with your cars handling dynamics or not totally comfortable with your suspension setup yet or something then these could be mildly dangerous if you’re driving hard. This isn’t that uncommon of aggressive summer tires though and traction seems to be pretty easy to correct with these so if they start to lose traction you certainly can recover. Also, they are fantastic in the rain and VERY resistant to hydroplaning in my experience.




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Little random bonus pic... I was visiting family over the Holiday and my Uncle (Retired Navy Veteran, BMW enthusiast, and great man) offered to let me put my car up on the lift for ****s and giggles. Don't recall doing anything noteworthy at the time, I had already been on top of things, but it was neat to see her up on the lift and learn some stuff from my Uncle!


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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #4 (Edited)
Getting Tuned!

I made those wheel/tire purchases within a month or two of purchasing the Passat in July of 2014 and it was pretty much right after that when I got a stage 1 tune. I went with APR. I was aware of the other big tuners for shelf tunes but I went with APR for a few reasons:

1) I had an APR dealer pretty nearby (NGP Racing in Aberdeen, MD)
2) APR is the largest and, I’m sure, most wealthy of the big tuners which tends to correlate to R&D/testing quality… that, and the fact that VW considers them a partner and offers their tunes in some locations, made me confident in the product.
3) Their stage 1 tune advertised the largest gains of any stage 1 tune on offer for my FSI (by a fairly significant margin as far as torque goes) and while some would say that APR inflates their numbers compared to other tuners that would only bring the
APR stage 1 tune down into the same power range at worst and I suspect they ALL inflate their numbers anyway.
4) I liked the power curve I was seeing advertised. Make no mistake, it is still peaky and leaves quite a lot to be desired up top but that is at least 50% because of the inherent characteristics of the K03 turbo. Compared to the other big tuners, particularly
REVO as I recall (and have heard from several sources), the APR tune has a more gradual curve yet is still satisfyingly savage down low (as really any K03/K04 tune is).

Those are the reasons I chose APR over the others for shelf tunes. Now if you’re reading this thread and currently debating over tunes, I’m NOT going to say that APR is “best”. That’s at least partially subjective at the end of the day. What I will say, is I had absolutely zero problems with APR over the 3+ years I had APR stages 1 – 2+ (more on that progression coming up) and was always very satisfied and enjoying my car.


Off-the-shelf Tuning vs. Custom Tuning

I want to address another subject to... The highly contentious and oft-debated "shelf vs. custom tune" subject. I am going to weigh in on the subject with my advice, which is coming from my personal experience in both camps (shelf tuning AND custom tuning/setups) as well as my experience as a professional software engineer and avid researcher when it comes to my car build. As a software engineer you better believe I've delved into every bit of minutiae possible and asked of the numerous tuning companies everything they would discuss about the tuning parameters, variables, tables, maps, and the software itself. Obviously they aren't gonna tell me any of their trade secrets but the point is that, just by the nature of my profession, I have more insight into the end-user differences that are achieved by shelf tuning vs. custom tuning... and they really aren't that significant. It boils down to this: if you don’t plan to go with a setup that more or less needs custom tuning (e.g. non-standard hardware) then just stick to a shelf tune.

That's because the reality is that shelf tunes are just as good as your average custom tune AS LONG AS they are paired with the standard hardware they are intended for. See, everyone has this notion that getting a custom tune when they are stage 1, stage 2, or basic bolt-on K04, is better than a shelf tune because it is more tailored to their car... it really isn't. Those shelf tunes from the big tuners are tailored to that hardware they are intended for already; they are, in effect, a custom tune in-and-of themselves for that specific basic bolt-on hardware. The second you deviate from standard bolt-ons and add non-standard stuff like high performance intake manifold (do NOT unless you’re going BT), or water-meth injection, E85, etc. that goes out the window though. THEN you want custom tuning because THEN you need a tune that can be tailored to your non-standard hardware to take full advantage of it. But that's only the case for a minority of enthusiasts/modders. If you have the basic standard hardware that the shelf tunes are written for you will get little-to-nothing out of a "custom tune." And the reason I threw "custom tune" in quotes is because most custom tuning companies do NOT actually give you a truly custom tune when you have basic bolt-on hardware because it would be a waste of their time; they already have a tune ready to go for that (just like the big "shelf" tuning companies). Why would they duplicate effort and tune specifically for each car when the stage 1/2/K04 cars with standard bolt-ons are nearly the same and any amount of custom tuning they do from one to the other is gonna net fairly minimal and possibly negligible difference in power from one bolt-on application to another. So for bolt-on stage 1 thru K04, a shelf tune is totally fine and generally the only thing you’re going to get out of a custom tune on standard bolt-on hardware is a bit more refined of a powerband and MAYBE a bit more power if your tuner really knows what they’re doing and if you pay for the time it takes to dial it in to that level. That’s best case scenario; worst case scenario is you’ll pay just for them to load a cookie-cutter file for your hardware (which will be at best as good as the heavily R&D’ed/refined shelf tunes) or they will do a more custom approach but it will take many re-tunes and more $$ to get it any better than a shelf tune which is already designed for the hardware, is heavily R&Ded, and used by thousands of feedback-providing users for the same application.

To elaborate on that, a proper tune will perform well regardless of environmental factors; whether you introduce load with the AC on, drive when it's very cold or when it's very hot, etc. the car should perform well. This is generally the case for shelf-tunes because of reasons stated above regarding R&D and because they have to be to be so mass-marketable. With custom tunes, however, the tuning typically occurs in very narrow scope. There are more environmental variables than you can count that can skew the data and tuning and while most of the time these variables are not significant enough to be total deal-breakers (in the sense that your car isn’t going to run horribly), it will prevent the tune from being as capable as it could be which is the biggest oxymoron of custom tuning

Properly tuning a car takes significant dyno AND street time. The idea that a custom tuner can do some pulls, log some data, change some figures, rinse and repeat, and have a tune that is magically better than a shelf-tune, for the right hardware, should be looked at with EXTREME skepticism. Rarely does a totally custom tune not require multiple re-tunes to be competitive, it’s just the nature of the game. Some people like that game, I like it, but not for a bolt-on stage 1, stage 2, or even K04 setup. Not worth the headache for minimal gain, at absolute best.

At the end of the day custom tuning is actually NOT all that much different than shelf tunes. They are all working with the same data, the same parameters, the same variables, the same tables, the same maps, etc. It's all the same process and the same techniques used to accomplish the same thing, the ONLY real tangible difference is that the custom tuners will adjust that stuff around your build and the shelf tune obviously does not. That is why I say that the ONLY reason to go custom tuned is if you have non-standard parts on your car that a shelf tune does NOT account for or take advantage of properly. This is why for stage 1, stage 2, and for K04, most "custom" tuners load a canned file anyway and it's no better than a shelf tune. It's basically the same thing because there is no significant variance to account for from car to car.

Hopefully that clears anything up on that subject and readers will see the merit of choosing a shelf tune from one of the big tuning companies if they are only planning for a basic bolt-on application. As for whose tune to go with, that's up to your budget and goals so weigh your options. Look at what they're all offering/claiming and consider ease of access to support from the company because, while it is fairly rare to have issues with a shelf-tune, you're at their mercy if you. Understand that most of these tunes are going to be pretty similar because, at the end of the day, there is only so much you can get out of the K03/K04 turbo. Both are peaky, peak early, run out of breath up top (much less so for the K04 of course) and there's only so much that tuning can do to flatten that powerband out and move it up the RPM range when the hardware itself dictates part of that behavior. So look at power claims, look at charts for powerband, and look at what Euro shops near you have which affiliations, that's my advice.


More Notes on Custom Tuning

For those that are considering the custom tuning route I have some more info to share. I'm going to take the not-so-popular position on yet another subject, this time on the overrated custom tuning option called Eurodyne.

Make no mistake, Eurodyne Maestro is a useful tool but it isn't all it's cracked up to be. Maestro "dumbs" down custom tuning so that it can be more approachable for end-users. Even then, however, it takes a good deal of know-how and trial/error to get a decent custom tune out of Eurodyne Maestro's suite and it is only going to be decent when it's done. That's because, as with all things, there is a cost to dumbing down a product. In this case the cost is that Maestro is not nearly as comprehensive as software such as WinOLS which give FAR deeper access into the ECU's tables, parameters, etc. or the software designed by professional custom tuning companies (e.g. United Motorsport) for their own use. So whether you really know what you're doing and use Maestro to tune yourself or hand it over to a shop with professional tuners, your custom tune with Maestro is not going to be as good as it could because you're gimped from the start since your control is limited and thus the thoroughness and maximum efficacy of your tune is lesser compared to custom tuning options mentioned above.

The only advantage to Eurodyne (and WinOLS) is that it allows the end-user to have control and to tinker themselves. Most of the time that isn't an advantage though because while there is a lot of satisfaction to be had in doing it yourself the end product from a user who is just dabbling is never going to be as good as a custom tune from a company/tuner that does it professionally. That's fine for some people but if you're a perfectionist like me and you want to know it's as good as it's going to get then Eurodyne is never the answer.

That's all regarding the Maestro add-on to Eurodyne... don't get me start on the base-maps that come with the main Eurodyne software. The base-maps released for Eurodyne are, and there's no other way of saying it, hot garbage. The logs I've seen from Eurodyne base-maps are consistently some of the worst logs I've ever seen. Some were literally unsafe.


A Warning About Unitronic

I will say that I have seen many logs from many different cars with Unitronic tuning over the years that I’ve been active in forums, facebook groups, cars & coffee groups, etc. and I’m typically not impressed. The cars run and perform well enough but from a data-perspective the tunes look lackluster; there is a difference between how a car drives with a given tune and how it is actually performing from a data-perspective and data doesn’t lie.

BUT, I digress, because that isn’t really the point I want to make. Though the sample of cars I’ve logged with Unitronic tunes is decent, I cannot fairly generalize what is still, ultimately, a small sample compared to the massive amount of cars out there with their tunes that I have not encountered. So I’ll leave that where it is… however, what I absolutely CAN do is point out a, frankly, deplorable business practice that Unitronic has for FSI platforms.

For the FSI platform they have a K04 package + tune that they insist works well WITHOUT upgraded injectors. On a TSI that would be 100% fine but the FSI has far inferior stock injectors. Unitronic does this to make their kit cheaper and sell better to folks who want to go K04 on the cheap. Instead of injectors, they include a fuel rail pressure regulator valve that has a MUCH higher crack pressure than stock (around 160bar which is even higher than the crack pressure on my uprated FPRV for my big turbo build/tuning). This is so that they can run insanely high fuel rail pressures to, essentially, force as much fuel as physically possible through the poor stock injectors in the hopes of supplying enough fuel for the K04’s increased air flow. The result: more strain on HPFP, more strain on injectors, more strain on fuel rail, and last but not least, it STILL does not provide enough fuel. The logs I've seen with this setup show that the engine is running very lean. So it's also unsafe for the engine. And Unitronic has the nerve to sell this kit to people and say it is totally safe and totally reliable. I find that deplorable. Data doesn't lie, but apparently Unitronic does.

If you are a reader whom has Unitronic tuning don’t take this as condemnation of your car or your choice to use Unitronic. If you enjoy it and haven’t had any issues with them then that’s great. For most people, that’s all that matters and that’s valid. However, when I found out that Unitronic had the above business practice it made me feel some kind of way. I can’t abide that and I wanted to warn readers about it in case any of my readers also value the ethics of a company when choosing to support them.




***Note: So at this point in the chronology of the cars build history we’re at about Fall of 2014, just a few months after I bought the car


The Obligatory CAI plus a Catch Can Of Course

By this point, not too long after the stage 1 tune, I decided to get a cold air intake. From research I knew not to expect much, if anything, at all from a CAI on a stage 1 car, but I figured why not? They’re cheap, add a bit of pop to the engine bay, and sound pretty cool. I do like a nice intake woosh, however, I DO NOT like that stereotypical BOV sound. Anyway, I frankly do not remember why at all but for some reason I initially went with the APR carbonio stage 1 CAI. It was overpriced (to no one’s great surprise) and it was only after I installed it that I realized I just really did not like the way it looked. I think this is in part because I just wasn’t a big fan of the stock engine cover that it integrated with to begin with and preferred seeing what was underneath and also because it didn’t really create even the faintest of intake wooshing noise. Faint was really all I was looking for, I didn’t want anything obnoxious but this stage 1 version of the carbonio intake just didn’t make any difference.

So I sold that in a matter of a month or two and put on a Forge “Wintake” instead. Not only do I like the look with the engine cover off but it has the added benefit of just taking away one extra step when I go to clean up engine bay or do pretty much any work in there. There were other reasons I chose the Forge CAI though. First of all, I liked the fact that the filter element was fully enclosed instead of just sitting on a plastic heatshield but otherwise totally exposed like most other CAI options. I later decided I wasn't a big fan of the carbon fiber wrap around the enclosure for the filter though so I eventually painted over that in gloss black. The most important reason I chose this CAI, though, is that in my research I came across info that verified the bung welded into the intake piping for the MAF was designed properly so that the MAF sensor is positioned just right in the intake stream. This was a criterion I was concerned with after discovering that not all CAI options are created equal in this area. The MAF sensor must be positioned/oriented just right in the intake stream to achieve accurate enough readings for optimal fuel trims to be calculated by the ECU. The MAF bungs for various other CAI do NOT all do this successfully; however, the Forge CAI was one that has been well documented to do so. It actually did not originally, but it was later revised by Forge to correct the issue.

I also added a BSH competition catch can at the same time. I feel like this is common knowledge to most by now but just in case… Contrary to how they are marketed, catch cans don’t do all that much in the way of preventing carbon build up on intake valves (they’ll slow it down some but that is all), but what they really do is keep your boost pipes and intercooler clean and relieve you of the burden of having the failure prone stock PCV. So still worthwhile. I was somewhat worried about freezing issues with the catch cans. While PA isn’t as cold as some more northern territories, it can easily get into the single digits at least sometimes in most Winters. The low temperatures in the Winter mean that the catch can fills up much more quickly with condensation. I concluded though that as long as the lines to/from the catch can lay flat so they do not have any valleys that condensation can pool in that I did not have to worry about the lines. I also decided that as long as I drain the can (after driving when the contents are melted) on a weekly basis so that it can never fill up and freeze at the top where the lines enter and exit the can then I shouldn’t have any worries there either. I have not had any issues with the catch can setup in the last 3 years, even one Winter when we had some negative temperatures. I think that, logically, anyone can run a catch can in any climate as long as they adhere to these rules which account for the only issues that could occur while running a can in freezing temps.

***Pro-tip: If you’re like me and you don’t want to run a vent-to-atmosphere setup or a drip line down to the ground because you don’t want any mess in your engine bay or underbody, then buy a fuel petcock/valve and install that in place of whatever drain plug your can came with. Usually the threading on the drain plugs for the various catch cans I’ve seen are all ¼” NPT threads. Then carry a small bottle/container in your trunk for draining on-the-go if needed. This combo makes draining much less of a nuisance, especially in Winter when you’ll be draining often.


IMPORTANT Note on Catch Cans vs. PCV Block-off Plates

If you fully understand what the PCV system really is for and what it does then you can begin to see why a block-off plate alone is not wise.

To re-cap: PCV stands for positive crankcase ventilation and, like most car parts, the name implies exactly what the system is for. During combustion it is inevitable that some gases from the combustion process will escape past the piston rings and down into the crankcase. This pressure must be evacuated in some way or else it is forced out of the weakest points around the crankcase, namely seals (e.g. RMS and another common one is all the way up on the valve cover oil filler neck seal). Enter, the PCV system. It alleviates this positive pressure, starting with the front PCV system. When the engine is in vacuum at idle the two-stage control system within the front PCV is such that vacuum pressure returns to the intake manifold due to a closed pressure control valve. With the factory front PCV on, when vacuum pressure is low enough/when you enter boost, the control valve opens and then pressure goes through the valve cover pass-through channel and to the rear PCV breather. The rear PCV acts essentially as a pass-through (with a check valve), as does the valve cover itself, because the front PCV is what receives the vented crankcase pressure first.

The catch can replaces the front PCV but it retains the flow path and full functionality of the PCV (minus front check valves). The block-off plate does not retain the full path and functionality. It is for this reason that guys with block-off plates frequently run into eventual issues with oil seeping out the oil fill cap area, increased likelihood of valve cover leaks, and increased likelihood of RMS leaks. Not good


IMPORTANT Note Regarding Noise You May Notice After Adding a Catch Can or Block-off Plate

After adding a catch can or block-off plate to an FSI with a cold-air intake replacing the factory intake you will notice a sort of "putting" noise manifesting itself in the intake ONLY at idle. I thought it almost sounded like an older percolating coffee machine when I first heard it. It may sounds threatening but it is actually harmless (as I will explain below). However it is very annoying and makes the car sounds like crap at idle so most folks want to get rid of it. I'll explain why the noise develops and how to get rid of it.

When the engine is in vacuum at idle the two-stage control system within the front PCV is such that vacuum pressure returns to the intake manifold due to a closed pressure control valve. With the factory front PCV on, when vacuum pressure is low enough/when you enter boost, the control valve opens and then pressure goes through the valve cover pass-through channel and the rear PCV breather, but now that you’ve removed the front PCV this control valve’s function is gone. Full vacuum at idle is no longer being contained by the pressure control valve that used to be there and is now defaulting to the rear PCV check valve which was not designed to serve this function. This manifests in your intake because your intake is obviously hooked up to the turbo post-rear PCV breather. Removing the rear PCV check valve will solve that and the harmless vacuum pressure merges with boost loop which ends at the intake manifold, the same end point of vacuum with the front PCV pressure control system; therefore once you go into boost this new routing without any front or rear PCV check valves behaves as normal.

To remove the rear PCV breather check valve you must remove the rear PCV breather pipe from the valve cover and turbo inlet, then using a flat-head screwdriver or similar tool you need to jab out the entire check valve and ensure no fragments are left behind. The exact design of the check valve depends on the version of rear PCV breather you have. Some are more annoying to remove than others, but each version has a cross-piece over top of the check valve that is part of a molded ring around the edge of the breather hose. You do not want to remove that ring/cross-piece if you can help it. If you do the factory hose that goes from valve cover to the rear PCV breather hose and is molded for exact fitment may not seal correctly so you would possibly have to use a different hose to connect them then.


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APR carbonio




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Forge Wintake + BSH Catch can







***Note: Winter went by after those mods and, apart from my usual religious and anal maintenance routine I developed, I did not do any work/mods to the car. Come early Spring of 2015 I did some more though…


The Classic Cam Timing Chain/Tensioner

Actually the first thing I did that Spring was maintenance, but not general maintenance. I decided to take on my first big mechanical task by replacing the cam timing chain/tensioner which is, of course, very well known to be an early killer of the FSI motors, second only to the cam follower itself. This job was far and away more complicated than anything I had gotten into at this point so it was very stressful. However, I was absolutely committed to learning hands-on, I did my research, I didn’t do anything rashly, and I came out smelling like a rose – a very sweaty, dirty rose. There was only one part that didn’t go that smooth and if you’re an FSI junky then you probably know exactly what it was… yep, everyone’s favorite exhaust cam bolt that takes that stupid poly-drive bit sheared like it was made of paper. Thankfully I was prepared with some EZ-outs and drill, etc. and was able to extract it. I used multiple magnets in between multiple brief drilling sessions to keep all the little metal curls from getting anywhere they shouldn’t be. This was still difficult and I was afraid for a time it wasn’t going to work. Finally got it out though and then put the exhaust cam lobe in a container filled with fresh motor oil and shook it around a bit, then let it sit. The thought there being that it would help to suspend any metal flakes that I may have missed. Suppose it worked, never had an issue after the job was done. I think the same thing that has helped me all along the way even to this day and what clinched this job for me is that every time I take on a job that is new to me (which is every time I do something new on this car) I make sure I research the hell out of it and I apply critical thinking and my very methodical, slow and steady type of approach to it. So that’s my best advice to new DIYers… slow and steady wins the race. You might be out there a lot longer than some people would – trust me I always am – but when it’s all said and done at least it’s done right the first time.

Unfortunately, I don’t have any pics of this job since there was already a fantastic DIY on VWV for it and I wasn’t ever really planning to have a build thread.


IMPORTANT Note on Identifying If You Have the Failure-prone Revision A Intake Camshaft

If you own a 2006 or early-2007 model FSI (actually any 2007 model FSI, just to be safe), then I highly recommend that you check which revision intake camshaft your car is equipped with. This can be easily done by removing the vacuum pump and checking the side of the intake camshaft lobe, as the revision A (the failure-prone one) looks quite different from the revision B part which is has been proven not to be failure prone. I will put a link below to a thread that has pictures to help distinguish the two from each other. You’d also be wise to take this opportunity to check out your cam timing chain tensioner because it is visible (partially) with just the vacuum pump off. You won’t see much of it but you can get a good enough view to tell if it is very worn down. You can see it between the top and bottom portions the chain with two orange-ish (they are white when new but orange-ish when stained with oil) plastic guides that the chain rides on. These guides wear quickly and lead to slack in the chain and inevitable camshaft timing mishaps.

My final word on the subject of the intake camshaft revision/type… if you find that you have the failure-prone revision A intake camshaft and your car has under 120K miles on it, you may be able to get the replacement covered under an extended warranty issued for this part. You may also need to actually have fuel pressure issues resulting from a badly scored revision A intake cam lobe for VW to honor the warranty though. Either way it is worth a shot, swapping the camshaft is quite a huge PITA!

https://forums.vwvortex.com/showthread.php?3754451




New Shoes... Again

I decided I didn’t really like my GTI Autobahn 17” wheels anymore so I sold them and got some wheels I did and still do truly love: the 18” OEM Smoked (Black) Karthoum wheels. I had these wheels for over 2 years as my summer set. I don’t have them anymore. That’s not because I stopped liking them though, there were other reasons for the change dealing with later modifications. In retrospect there was probably a liiiiittle too much black with them but the silver accent (which matches the chrome trim on the car) helped to break that quite a bit. I’d have never gone with full black wheels on a black car, no way.

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A Better Shifting Experience

At some point that summer I decided that, more than anything else, the thing that was keeping me from enjoying my car was the vague, sloppy, boring shifting feel. It was just robbing me of a real connection to the car. So I decided to fix that. Enter the APR short shifter and solid shift cable bracket, plus ECS solid shifter cable bushings.

At this point I’m probably starting to seem like an APR fanboy… I’m really not, the only reason I spent way extra on the APR short shifter is because it allows for side-to-side throw adjustment too. I set it to full short throw for front-to-back and something around 75% shorter for side-to-side. For anyone wondering if this has ever caused me any issues with going into the wrong gear, the answer is no. Not once, not ever, in nearly 4 years now. I think this would only ever be a concern for new manual trans drivers, if at all.

Now, what the short shifter does and how it improves the shifting experience should be pretty obvious as it just allows you to shift a bit faster and crisper due to shortened travel of the shifter, and I think even the solid shift cable bracket and solid shifter cable bushings are pretty well understood by most folks who’d be interested in a build thread like this. But, for the uninitiated, I’ll explain. For manual trans owners, the shifter cable bracket is the metal, roughly “W” shaped bracket bolted to the top of the trans though which the shifter cables pass and clip on to. For most models, this bracket is plastic and it flexes during shifting, which translates to slop in the shifter. So it should be apparent what replacing this with a metal bracket does. Likewise, there are rubber bushings on the links on the end of the shifter cables that attach them to the levers/relays on top of the trans which are, in turn, connected to the shift forks in the trans. These rubber bushings also allow slop, A LOT more than that shifter cable bracket actually. Upgrading these shifter cable link bushings to solid bushings is an absolute MUST for manual owners in my opinion.

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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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Discussion Starter #5 (Edited)
***Note: Summer 2015…


Time To Make Some More Noise… And Fuel Pressure

Next I decided to install a Billy Boat 3” full turboback exhaust which I lucked out and got for just over $1000USD on ModdedEuros at the time which was $400 cheaper than elsewhere. Though the welds on the unit I received weren't anything to write home about, they weren't bad either (I've noticed zero issues around the welds in the last 2, nearly 3, years). It’s a beautiful 304L stainless exhaust. My research indicated that it had higher quantities of nickel and cadmium in the alloy than the other 304L exhausts I was comparing it to, which, of course, means better corrosion resistance. Still looks fantastic to this day with no rust formation that I’ve noticed despite a few salty winters since I got it. Fitment was completely perfect. It has a high-flow 100-cell cat (whereas most catted aftermarket exhausts have 200-cell compared to OEM 300-cell). The only other exhaust that I might have gotten over the Billy Boat would have been a 42DD turboback, I’m a big fan of that company and the quality of their work from examples I’ve seen in person, but I couldn’t justify the considerably higher expense. Besides, Billy Boat used to make APRs exhausts for them so that is at least some indication of their quality, I’d say. I like the tone of this exhaust a lot. It is obviously aftermarket but it’s not obnoxious by any means and is quite civil during highway cruising. It really growls at the 3K – 4K RPMs, where it sounds fantastic on accel or decel.

At this same time I also installed an APR upgraded HPFP and got flashed to APR stage 2+. The gains were pretty minimal and there isn’t much to say there.


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First Steps To Locking It Down

Last thing I did that Summer was install 034 street density motor and trans mounts to reduce wheel hop and trans movement/slop when shifting under heavy acceleration. It definitely did accomplish that. What it also did, that I wasn’t expecting, was add a bit of an angrier tone to the motor itself under hard acceleration. A nice bonus!!! Makes sense since the mounts absorb less vibrations from the engine and sound is, after all, vibration too so more of that engine sound makes it through to cabin.

These mounts marked my first venture into the classic DD vs. track conundrum. Not that my car was track ready or even close to it at that point (I was still on stock suspension with loads of body roll) but just that stiffer engine/trans mounts aren’t something that everyone would necessarily consider a DD mod. In my opinion and experience that’s not a concern at all. I am extremely anal about interior noises, vibration, and harshness (NVH), and while these mounts added some it was in no way distracting or annoying, even in a dead silent car with no music or conversation. Interior rattles are gremlins anyway and they come and go sometimes for seemingly no reason at all. I’ve tracked plenty down and stopped them with foam tape behind critical areas of the panels, but I’ve had even more that I never tracked down because they just disappeared and never came back. Adding stiffer mounts is a drop in the bucket honestly, I think any DD can have them with minimal concerns over NVH as long as they are a modest change in durometer of the rubber or polyurethane like the 034 “street” density mounts. A “track” density mount may be a different story.

Bottom line… my car was, and for the foreseeable future will continue to be, intended to strike a good balance between a street car and a track car, and since I’m very finicky about refinement it’s a safe bet that anything I do to my car is fine for a DD unless I indicate otherwise. As it has evolved and my driving tastes have changed a bit I’ve become a bit less finicky/anal since the first year or two I owned the car, but at this point in the chronology of the build thread I was still in that more finicky phase so you can trust those engine/trans mounts I have recommended are good for the discerning DD'er. Now, I should note that these days (e.g. NOT at this point in the chronology of the build thread) I've mostly taken it off of DD duty. I'll take it to work when it's nice out but otherwise I drive my truck now that I have a shorter commute and way too much money into this car haha. So where once I intended my Passat to be maybe 70% DD / 30% track, it's a solid 50/50 these days. Nevertheless, I still think that following my model is a good baseline for what you can get away with on a DD and still be totally comfortable with as such; ultimately, even today with many more “harsh” mods that I haven’t covered in the thread yet, the car is still extremely civil and not the least bit annoying to DD.
HOWEVER, there is a big caveat I almost forgot to mention… I do genuinely believe that part of that is due to the fact that it is a Passat; one thing I love about the Passat over the Jettas and GTIs is that the interior quality, fit, finish, and noise levels, etc. is QUITE a bit superior and nicer. I think this factors into how much it is (not) affected by mods like engine/trans/subframe mounts, etc. I’ve been in Mk5 GTIs with very similar setups and they are notably less civil in the cabin.

Anyway… here are some pics, you can see the engine mount but it looks stock because 034Motorsport builds their mounts out of the factory housing. Unfortunately, their factory housings do not have the unused bolt-hole that the mount I had from the factory did which I had used to bolt in my catch can’s bracket… I realized this only after I installed the new mount so I had to ghetto rig a new bracket system from spare parts I had laying around. Turned out decent enough. Decided to keep it up until the point I stopped running the BSH catch can (more on that later)…


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1,818 Posts
Discussion Starter #6 (Edited)
***Note: Early Spring 2016…


Clutch Time

2016 was a big year for me and my Passat that started out with drivetrain upgrades because my clutch started slipping in the Winter. Whether this was due to winter cold air bringing in the boooost season so that the car might have been putting out a bit more power or whether it has to do with the temperature coefficient for the clutch material being less favorable in Winter for tolerating the heat produced by bursts of torque, or maybe both, I’m not totally sure. But either way, it was too much for the stock clutch which eventually starting slipping any time I went WOT in 3rd gear or higher. The decision on what to get for the clutch upgrades was the first mod that I truly belabored the plan and research for to an almost nauseating extent; I belabored whether to go with a OEM+ sort of solution – retaining a dual mass flywheel (DMF) and performance organic disc with a much stronger pressure plate – or to go with the more standard single mass flywheel (SMF) route with aftermarket options. There are a couple prominent options in the OEM+ category, including the HS Tuning RSR clutch kit (essentially a Luk brand TTRS pressure plate and clutch disc, possibly modified) and a few different varieties of Sachs Race Engineered (SRE) kits. Yes, Sachs has a racing engineering department and they do sell OEM quality performance parts. Quite attractive but also quite expensive, unfortunately. To be fair though, all the OEM+ options are expensive. On the other end of things there were numerous aftermarket options available, all of which were paired with a SMF. These included South Bend Clutch, Black Forest Industries, Clutch Masters, and SPEC. There were some other companies/options that came on my radar but during my research on them it quickly became obvious there was too little info available on their options for VWs for me to be comfortable so I quickly discounted them and, therefore, have nothing to say about them here.

I researched the above companies, and some of their options, intensely and then began narrowing down my list. For those that stayed on the list, I would then look more in-depth at the individual component choices of their respective offerings. The survivors that stayed on the list from the above were the HS Tuning RSR kit and South Bend Clutch. I nixed every other option from the list for the following reasons:


Info on Vendors, Flywheels, and Pressure Plates

I nixed the SRE option for the OEM+/DMF route because the particular Sachs pressure plate used in these DMF-compatible setups had some documented instances of failure under only moderately demanding use whereas the significantly beefed up Luk TTRS pressure plate included in the RSR kit had no such documented cases. Indeed, I could not find a single solitary case of disappointment in the RSR kit. Every review was glowing and it consists of quality OEM parts just like the Sachs kits. The RSR kit was on par with or cheaper than the SRE kit options as well. I nixed SPEC first because I saw FAR too much negative feedback on the quality and longevity of their parts and their power-holding figures for the parts were very vague/not reassuring. I’ll give them this, they are priced very competitively. So competitively, in fact, that this too didn’t inspire confidence. I had to wonder if they weren’t just straight-up cheap parts, which was a notion re-enforced by my research thus far. There is a line between charging an arm and a leg like SBC does and just having straight-up cheap parts. I could not find any info to inspire decent enough confidence in SPEC so I nixed them. That had my hoping to find a good alternative to the more expensive South Bend options in the form of a BFI or Clutch Masters option. But I had to nix these too at the end of it all. BFI clutches are made and supplied by a company called Competition Clutch. While I didn’t find anything damning about Competition Clutch and they may be quite alright, I didn’t find anything inspiring either. There just wasn’t a whole lot of info to go on specific to feedback in VW aftermarket applications. I lastly nixed Clutch Masters. This one was much more subjective. I ultimately nixed them because it seemed to be a consistent trend everywhere I read about Clutch Masters, that their setups caused a significant amount of gearbox chatter (more on that later). I also found that Clutch Masters outsources their component manufacturing, but I couldn’t find out where so that left a big question mark, whereas SBC does their manufacturing in-house for applicable components. I’m pretty sure they use a modified and powdercoated Sachs SRE pressure plate though like just about everyone else. Sachs makes them for SMF applications too and that one is basically the standard for aftermarket SMF and single-disc applications that rebrand the disc. While the controversy of parts kept in-house versus outsourced doesn’t technically go anywhere objective, I personally just tend to feel more comfortable with the former. So I settled on SBC for the SMF route.

With the RSR and SBC options as my leading choices, I next had to look at and compare the components themselves. As I was targeting a DD-friendly setup I preferred either to retain a DMF (like with the RSR kit) or, in the case of going the SMF route, I preferred to have a steel flywheel, not an aluminum one. While the aluminum SMFs are much lighter and lighter flywheels translate to quicker engine revving up and down due to less inertia on the crankshaft end, it also means significantly increased gearbox chatter, which can be annoying for a DD vehicle. Gearbox chatter is especially amplified with the air con on in the Summer since this puts additional load on the engine which is transmitted along with the gearbox chatter into the cabin. The heavier steel SMFs, by comparison, are still typically much lighter than the factory DMF but not so light that gearbox chatter is too intense. To that end the SBC kits suited my needs well enough since they include 19LB steel flywheels (7 lbs lighter than stock). But these would still contribute to some chatter which could not be avoided so this was a consideration on my mind.

There was nothing of particular note on the distinctions between the pressure plates for each kit at the time I was making this decision. I trusted that they were both quality and were both rated for significantly higher power-holding than I planned to need. However, the RSR kit did get the edge here as well because the Luk TTRS pressure plate included in this kit (possibly modified as well) was stated and tested to be good for applying enough clamp force on the clutch disc to hold up to 480 ft-lbs of torque, whereas only the most expensive of the SBC kits I was even considering could match that (and it had draw backs in other areas I will discuss). So, technically, this was an easy win for the RSR kit too.


Info on Clutch Friction Materials

Lastly, I considered the clutch disc friction materials themselves. The clutch disc included with the RSR kit is a performance organic friction disc, as are the clutch discs used in the SBC Stage 2 Daily and Stage 3 Daily kits. The SBC Stage 2 Endurance and Stage 3 Endurance kits, which I gave brief consideration, used different materials. The Stage 2 Endurance uses a hybrid clutch disc with performance organic material on one side and sintered iron material on the other, whereas the Stage 3 Endurance uses Kevlar friction material on both sides. I immediately discounted the Stage 2 Endurance because, put simply, hybrid discs are a gimmick. The idea is that the pressure plate side of the disc uses organic material to make engagement and start performance similar to OE (less aggressive) and the flywheel side uses sintered iron to allow for significantly higher static to dynamic frictions ratios and temperature coefficients for better performance under high heat spikes/abuse. Based on my research (some of which I will link below), I found that this works but only to a small extent; yes, normally a performance organic disc would have similar to OE start performance and, yes, the sintered iron itself does have those properties. Those things would matter if both sides of the disc were made from the same one of those materials. But that's not the case here. Not only do these materials definitely wear at different rates and under different conditions so the disc can develop some odd behaviors over the course of its use, but it's not ONLY the material on the pressure plate side that determines what engagement is like so you're not actually getting OE-like clutch engagement just because the pressure plate side is organic. Likewise, just because you have sintered iron on the flywheel side does not mean your clutch disc is automatically up to the task of handling the immense power and heat that sintered iron discs are usually designed for; that is because both sides of the disc will be exposed to heat from use and the least common denominator here is the organic side, of course. The disc is limited by that. Also sintered iron discs wear flywheel faces incredibly fast and while they do have high heat spike tolerance, if you expose them to excessive slippage (e.g. in traffic) they will glaze fast and NEVER recover. Fully organic (both sides) discs can recover from minor overheating/glazing after the glazed surface is worn off. I discounted the Stage 3 Endurance shortly thereafter for similar reasons. Although Kevlar disc materials mimic organic in their engagement properties (not very aggressive) and start performance, they are similar to sintered iron in that they have very little tolerance for slippage necessary in some DD traffic and they can NEVER recover if overheated. That characteristic does not make for a good DD clutch. So at this point I had only the SBC Stage 2 and Stage 3 Daily options left versus the HS Tuning RSR kit. All used performance organic discs, all were rated for far more than enough torque than I ever conceived I’d be making (which is funny looking back), but the RSR kit was rated for more than either, it would have absolutely no gearbox chatter, and it had rave reviews everywhere I looked (whereas even SBC had hit-or-miss reviews). I chose the HS Tuning RSR kit.


Impressions of the RSR Kit So Far

I think I made a good choice. I got a clutch kit that was strong and sporty but not brutal in traffic. One that could handle some degree of feathering the clutch, which of course you avoid 99% of the time but can’t always avoid in traffic or creeping into a garage or out of one in reverse, etc. I got a kit with better longevity since OEM organic clutch discs can last well over 100K miles on unmodded cars if the operator is an experienced manual driver. And I got a kit that wouldn’t require me to deal with the classic SMF gearbox chatter noise and I also wouldn’t have an unbalanced crankshaft.

Sure this would all come at the expense of the quicker revs and less rev hang to be had with a lighter SMF but that was a trade I was willing to make for my DD. Best of all, based on independent reviews I found and HS Tuning’s own tests, there were much more powerful cars using and abusing it for over 50K miles with zero issues. There were no shortage of people going through SB and CM kits in much less time. SB and CM seem to be pretty reliable on the whole, but it seemed like sometimes you’re just settling for a possible crapshoot when you go with those brands. Many people with no problems, and many people with defective kits, or just kits that crapped out within and unacceptably short amount of miles. I decided to take a chance on the RSR, hoping that as an OEM-like solution it would have similar OEM longevity. Time will tell but the weak link, in terms of longevity, may be the DMF I retained with the RSR kit. While I did elect to upgrade to the Golf R DMF which is supposed to be a bit stronger, ultimately, it has the same overall weakness and concern of all DMFs. The internal springs that absorb the torsional forces between the two opposing flywheels will eventually stretch/fail. I consider this to be the weak link of the setup and may eventually regret the choice. But I’ve put upwards of 25K on the kit so far (as of Summer, 2018) with ZERO issues whatsoever and I ABSOLUTELY love it. It was exactly what I was going for: super sporty, super engaging to drive, combined with my shifter upgrades previously mentioned, but also forgiving enough to be tolerable in DD situations. It’s a far cry from stock with that heavy pressure plate, but very tolerable for DD.

That was my thought process in 2016 anyway. I am happy with it and I still stand by it, I believe it was the right choice at the time. I should say though that my tastes have changed somewhat over the last couple years, enough that I might tolerate a more aggressive setup when the time comes. That time may be sooner rather than later now after having completed so much additional modifications, not the least of which being the upgraded turbo. Once I’ve worked my way up to supported the maximum power this turbo can output I could get fairly close to the maximum capabilities of the RSR kit (to close for comfort and buffer room anyway) so I have my eye on an upgrade that did not exist at the time I was looking in 2016. But that’s possibly a post for another day ;)


Oh and I also added a stainless steel clutch line at the same time. I think it’s pretty common knowledge that these simply improve the firmness of clutch pedal application feel since the stainless steel lines do not expand under pressure like the factory lines due, so not much more to say about that. I also installed an ECS clutch bleeder block. This frankly was a part I installed mostly just to do it while I was at everything else. I was dubious about how much of an impact it would actually have; supposedly because it doesn’t have a restrictor like the factory unit it allows for more brake fluid flow rate to the clutch line and thus makes the clutch engagement a bit sportier/touchier. I can’t really speak to this specifically because I installed it amid those other mods too so… it isn’t plastic and it looks nice I guess! That’s all I have to say for that.

Unfortunately I don’t have any pics of the clutch parts install as, again, I never expected to do a DIY. I did these installs in March of 2016 if I recall currently.


Resources on Clutch Disk Friction Material Info

http://www.uucmotorwerks.com/CLUTCH/
https://www.phoenixfriction.com/t-clutch-materials-explained.aspx




Some Preventative Maintenance

Next up, and about a month later, I did timing belt service, water pump, etc. Again, no pics :(. Not much to say on that, basically a routine maintenance even though I did it a bit on the early side, but it was at this point that I felt like I could say I had “graduated” from a novice DIY mechanic to a pretty competent and capable one. I got a pretty big confidence boost from these projects!!!




***Note: Spring/Summer 2016…


Lost Some Gears

I do have some pics of the few other things I did in Summer of 2016… I had one of my shifter cables stretch/fray on me. I lost 2nd, 4th, and 6th, and the shifter went limp when trying to engage those gears so I quickly deduced this had to be a cable issues since it was only gears that were a backward throw. The very first time it happened in 2nd I thought I had a shift fork issue or something like that but then when it happened in 4th and 6th and started thinking there had to be something to that and checked the cables. Here is what I saw:


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So I dropped the shift box and installed new OEM shifter cables. It was actually quite a PITA…


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An Important Note Regarding Leading Cause of Damage to Shifter Cables

To this day I still don't know exactly how that cable got that bad. It's not a particularly common thing to happen, though I have seen some threads of users who've had the same issue. One leading cause, however, is when the shifter cable comes into contact with/very near to the exhaust downpipe. This is more common on certain aftermarket downpipes, depending on the bend angle in the pipe and its fitment. If the shifter cable comes into direct contact with the downpipe it will be damaged over time. I don't know whether this was or was not the cause of mine failing. I tend to think not because it would have had to be pretty far from over where it naturally settles to have come into contact with my Billy Boat downpipe. To be safe though, I made sure that when I installed the new one I routed/positioned the cable as far away as possible. I have NOT had any issues since then (a bit over 2 years now). I am also positive that the failure did NOT have anything to do with the various upgrades I've done to shifting components. It was either a "wear over time" thing, or related to the downpipe. My cable was easy to situate away from the downpipe but, for those who are not able to do this and are concerned for their shifter cable, there is a bracket made by 42DD that can be easily installed to hold the cables away from the downpipe.




A Shiny New Knob

Not long after that I figured, hey why not get a new shift knob while I’m at it. So I added a Raceseng “Slammer” stainless steel shift knob. It’s a 1.1lb, beautifully machined steel shift knob. Absolutely exquisite, yet very simple. Not a fan of leather or delrin knobs. I wanted something hefty and classy yet simple looking. I also like that it’s a particularly large and round knob which fits my hands well and is good for the a side-grip which I prefer to a top-grip for shifting (can’t wait for the first post from somebody who takes that out of context haha). Make no mistake, this knob is very heavy. Thinking of a shifter as the big lever that it is, you can observe the following physics: the longer the throw, and the higher up the knob is positioned in relation to the shifter stalk (essentially a longer lever), the more force is applied in the shifting motion and the follow-through, which would make a really heavy knob a bit too much. But this is balanced out by the fact that I have a really short throw setting for my short shifter AND I have my knob positioned pretty low (shorter lever). It means I have to give it a bit more oomph initially to overcome its weight (which I like) but because the throw is so short and the knob is so low there is less force/momentum than there otherwise would be. It’s all balanced out. Between that and the other shifter upgrades it leads to a shifter that requires a short but hefty and positively engaging, very mechanical feeling shift. I’ve swapped out some 0.5lb to 0.75lb weighted knobs to try them out for a good few days and just didn’t like it. I think it all comes down to the combination of this knob with my preferred throw distance. I think they just complement each other perfectly. If it was a longer throw I don’t think I’d like it as much. But as it stands I love it and, as simple as it is compared to all the other upgrades I’ve done to this day, it is one of my favorite aspects of driving my car. I’ve been lucky enough to drive more expensive, sporty cars that don’t come anywhere close to as engaging when running through the gears.

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Gotta Love More Numbers

Lastly, I installed a P3Cars VIDI multi-gauge into the left-most driver’s side air vent. Super clean gauge and pretty darn handy for its multiple data points. Not quite as extensive as a Polar-FIS MFD upgrade but less fussing with it required to get most of the same data and I like the display more. I’ve found it to be pretty accurate. It reads all its values EXCEPT for boost from the same blocks as VCDS does (which are mostly reliable). Boost is read from there but then, depending on the program you select, will have some correction formulas applied. These can help with accuracy in some cases for tuned cars but can be hit-or-miss too. I’ve had no issues getting accurate readings as compared to analogue readings but YMMV. I know some people who have. This can easily be fixed by just running an analogue vac line to a 8-bar MAP sensor you can get from P3Cars to plug into one of the inputs on your gauge and transform it to analogue boost reading, which I did out of necessity when I went BT. I mainly went this route because I wanted multiple data points without a ****-ton of gauges; I’m in the minority of folks that don’t actually like gauges/pods on my wheel/dash/pillars honestly.

Due to a shipping error I wound up with a P3Cars gauge with white/red color scheme intended to match the interior lighting of other models. Of course, I only found this out after installing and turning the unit on. That’s what is reflected in the pic below but I did later exchange it for the red/blue scheme to match my interior lighting.

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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #7 (Edited)
***Note: Early Spring 2017…


This year marked an even bigger year than the last. This year was when I really shifted my Passat towards a track-ready car because it was all about braking and suspension upgrades, which were honestly overdue.




If You Go Fast You Gotta Stop Fast

The year started out with a big brake kit (BBK) in March. I was looking at options and also asking around and happened to stumble upon Ryan Jacob’s (HYDE16) own StopTech ST-40 BBK for sale since he was upgrading to a 6-piston setup. A 6-piston setup would require an upgrade to TTRS master brake cylinder and that was more than I wanted to get into myself. So I settled on his StopTech 4-piston kit w/ 328mm X 28mm rotor setup, stainless steel lines, etc. He had also had it properly powder-coated with a sharp gloss black powder-coat since StopTech calipers have notoriously poor single-stage paint. For the price he was offering it was almost a no-brainer. So I bought the kit, installed it, put in new pads, and some ATE Typ 200 fluid, and that was that.

Now, before I go on any further I want to point out that there are very pervasive misconceptions about BBKs floating around car enthusiast communities. For now, it will suffice to say that it is actually highly unlikely that a street-only car stands to benefit AT ALL from a BBK. Of course, a car intended for any track duty likely will. Later in this post you will find a VERY in-depth and technical explanation about why BBKs are literally no help for almost any street car and, moreover, in some cases are actually counterproductive.

Moving along… initially I stuck with the StopTech sport pads which are StopTech’s metallic aggressive street/light track pad. These pads need to warm up a bit so they are truly at their best in more aggressive street driving, but they are still perfectly fine, safe, and civil in normal street driving. They can also hold up to light track use VERY well for their price. There are certainly FAR better options for track duty but not anywhere in the price range. Real race pads cost a good deal more. These pads are a really good value. They do dust like CRAZY though… but that’s the trade-off typically.

BEFORE I installed them I decided to put a coat of CarPro CQuartz DLUX (a semi-permanent ceramic coat) on the calipers to add protection over the powder-coat itself.

I know the only pic with kit installed is pretty dreadful but oddly it is the only pic I have of the BBK installed BEFORE I also did all my suspension work (which was shortly afterward), and I'd like to save those for that section of the build thread... so no worries, there will be plenty of better eye-candy later :)
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I also did rear pads at the time and decided to do the StopTech sport pads for rear too in OEM size since I kept OEM calipers for rear. Since I decided to replace the rotors as well I had to remove the caliper carriers and HOLY MOLY were those M14 triple-square bolts for the rear caliper carriers a bunch of absolute bastards! Since the last inch of those bolts are exposed to the elements they get very corroded… my Craftsman C3 cordless impact gun (pretty powerful for cordless) didn’t do jack to those bolts. I wound up soaking them in PB blaster, heat cycling them with a propane torch multiple times, and then applying my entire body-weight to almost 4ft of breaker bar to crack them loose and even then I barely got them. YMMV, maybe mine were extra tight, but either way… you’ve been warned! I actually kept the most difficult one as a trophy that I have on display in my house!

Anyway I replaced the stock rotors with Adam’s custom rotors in a standard slotted type.

A few words on rotor type... this is a hugely overblown subject. The reality is the type of rotor you choose, whether it be blank, slotted, drilled, whatever, makes veeery little difference for performance. I'd get blank or slotted, NO drilled. Drilled is an aesthetic thing only, no matter how much every company trumpets the claim that they are for better heat dispersion, etc. The fact is drilled rotors are just for looks and the only thing you're gonna get with them is a greater risk of heat cracking your rotor because its structural integrity with all those holes is weaker. Not saying it’s likely at all on a street car, just saying it’s more likely. On top of that, heat dispersion efficacy is dependent on mass. It’s simple physics. The more mass there is to transfer heat into the better the dispersion. Guess what is being removed from those fancy drilled rotors with each hole… mass. So unless you really just love the look of drilled rotors then stay away. The same marketing claims about slotted rotors when it comes to the difference they make because of heat/gas dispersion is mostly hocus pocus too but at least slots don't sacrifice structural integrity. I also like the way slotted rotors look (unlike drilled which I think look ugly) so I'd go for slotted. They can shave your pads down a little faster though. Two-piece vs. one-piece isn't a huge matter either; yes, two-piece will be lighter which reduces unsprung weight and can have a tangible affect on acceleration and stopping if reduced enough, but you'd have to shed a lot more unsprung weight in other areas too before you'd really notice. Since two-piece rotors are usually sold as part of big brake kits though they benefit from being larger than the OEM one-piece rotors and it's rotor size that is the biggest factor to consider in upgrading (because, once again, more mass to them).

I determined that the possible slightly better gas dispersion through the slots compared to blanks was worthwhile, as well as water dispersion (assuming any water on a rainy day isn’t instantly vaporized when it comes into contact with these parts), and plus I like the way slotted rotors look.

I did decide to remove the calipers completely and paint them at this time. I went pretty cheap and just used a can of Rustoleum high temp black paint to see if it would last. Honestly didn’t expect it to last too long but it surprised me. I did plenty of coats and it has held up perfectly for over 2 years now


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Notes About Pad Upgrades

The very first thing, and sometimes the only thing necessary, to consider for a street driven car is a street performance pad or a light track/auto cross pad. The major criterion to consider is the pad material; metallic or ceramic mainly. Metallic dust more but are cheaper and good ones have much more stopping power than ceramic and consistent bite when hot or cold (if they are designed for street use that is). Ceramic barely dust but bite is inconsistent as they work best when they are hot, they also don't tend to bite as well as top-tier metallics. A lot of people assume they are superior because they are on high end cars... not true. The truth is that ceramic brake pads are meant for long life and minimal dust. Good ceramic pads will never outperform comparable good quality metallic pads. Braking power is ultimately determined by the coefficient of friction between the two braking surfaces and the exchange is in the form of pad material as the pads are softer than the rotor (except for some race pads; more on that later). So a good rule of thumb to go by is the more dust a pad makes the better it stops. It’s a bit of a generalization but it’s basically accurate. Observing these laws of braking physics makes it clear why performance ceramic pads cannot outperform performance metallic pads. The other criterion to consider is pad temp range, in other words how much they can handle before you get brake fade (overheated brakes). Brake pads have a maximum effective temperature range and an optimal temperature range in which they work best. For street and auto-cross/very light track use a high performance street pad is ideal because these have a effective temperature range starting at 0 degrees, which means they will actually work well when you need to stop in a pinch and you haven’t used your brakes for a few moments. Unlike generic street pads, a performance street pad will also have a fairly high maximum temperature range before they fade (usually plenty high for street but not nearly high enough for anything other than LIGHT track use). A dedicated race pad, as you might expect, has a temperature range that starts at least a few hundred degrees above a street pad and often times several hundred degrees. These pads should NOT be relied on to stop you properly during most street driving. They will also wear your rotors down VERY fast because when race pads are cold they are working in full abrasive mode and are actually harder than your rotors until they are heated up and start transferring pad material instead; you will pretty much never heat them up enough for this to happen on the street. StopTech has my vote for most affordable, effective street and light track pads (their “street” and “sport” line) which I used for a few years and enjoyed. They are incredibly priced for what you get. Lately I’ve been partial to Porterfield as of time of writing (Fall, 2018).


Notes About Brake Fluid

If you have a premium performance street or light track pad with appropriate heat range, as discussed in the previous section, on your factory brake setup and you’re still encountering brake fade on the street then I can pretty much guarantee it is your brake fluid. It’s NOT time for a BBK, it’s just time to flush your brake fluid/bleed the system. In most cases the OEM brake fluid is sufficient and it just needs to be replaced. That’s because brake fluid is hygroscopic, which means it attracts water. Over time it becomes saturated with more water content which lowers its efficiency in dealing with heat. Fade is more likely to occur in older fluid (over 2+ years) and when pads are low because thinner pads means more heat transfer from the rotor/pad to the caliper and thus more heat transfer to the brake fluid. All brake fluids have a wet boiling point (boiling point when a sufficient percentage of water has saturated the fluid) and a dry boiling point (boiling point when very little to no water has saturated the fluid). The dry boiling point is pretty much only representative of your brake fluid for the first couple months it is in the car, after which it starts to shift towards the wet boiling point. Again, NEW OEM fluid every year or two is generally sufficient but for those that do not want to flush the OEM fluid that often or for some drivers who reach high speeds and demand serious fade resistance, then higher end brake fluid isn’t a bad idea because it will have a higher wet boiling point and thus you can change it less often and maintain high fade resistance. That is the characteristic to look for: wet boiling point. ATE Typ 200 is generally the best value for a performance brake fluid at only $15/L with modest boiling points. Motul makes a couple that are a bit better but 2x as expensive. Castrol SRF is the king of high wet boiling points. One could go an entire track season without replacing it because it has an insanely high wet boiling point (nearly as high as ATE Type 200’s dry boiling point)… but it also has an insane price tag!


IMPORTANT Notes About What BBKs Are For/NOT For

Let’s start off by discussing the physics of what braking actually is/how it works and what actually determines stopping distance. Keep in mind that as counter-intuitive as it may seem for some, the brakes are NOT what is stopping your car. The tires are technically stopping the car because the tires are what are in contact with the road. The tires are effectively the real brakes since it is their friction against the road surface that ultimately slows your car down. Of course, brake pads/rotors operate on the same principle of friction between two surfaces, but since they are not in contact with the road themselves they are only indirectly stopping your car. That said, the first criteria for better total braking/stopping power is technically better tires that can maintain a higher coefficient of friction with the road surface because if you exceed their limitations your car is obviously not going to stop as soon as you’d like. This means softer/stickier tires and those that can withstand more heat since heat degrades coefficient of friction. But this section isn’t really about tires, I digress… The next criteria is the coefficient of friction between the brake pads and the rotors. Achieving the highest possible coefficient of friction between pad and rotor is what will ultimately help you stop sooner/faster because that means the greatest possible braking force on the hub and ultimately delivered to the wheel/tire. Guess what does NOT have ANY direct effect on coefficient of friction?... Size (mass)!

But guess what absolutely DOES?... Pad material! And another one is heat! If the heat generated from the friction goes beyond the pad materials physical range for optimal coefficient of friction THEN, and only then, will stopping distance be hampered because then coefficient of friction between pad and rotor decrease, which means less braking force ultimately delivered to the tires. THAT is where bigger brakes come into the equation. Bigger brakes do allow better heat dissipation due to their larger mass (larger thermal capacity) so bigger brakes achieve better resistance to brake “fade” (which is when brakes heat up past their optimal heat range).

Therefore, the only instances in which bigger brakes improve stopping distance are those when the BEST pads possible for a street car (pads where the coefficient of friction optimal range starts at 0 degrees and goes as high as can reasonably be expected of street pad material) and are still routinely fading. This is highly improbable for a street car. There are high performance street pads with such high optimal ranges (e.g. Porterfield R4-S) that if you manage to overheat them then you are likely driving truly foolishly (even for a spirited driver/enthusiast). Pads like I mentioned above have and optimal range for coefficient of friction that starts low like any street pad but goes up to within only a few hundred degrees of many race pad (whereas race pads optimal range go higher but also start higher so they aren’t so good on the street where brake temps will be low at times). If you are having brake fade on the street even with a pad like that, and regardless of the amount of power your car makes, then the fade may well be old or poor quality brake fluid, not the size of your brakes.


IMPORTANT Notes About BBK Upgrades Regarding Brake Bias/Balance

One thing I’d like to note to readers is some considerations regarding BBK setups that aren’t often taken into account. There are a lot of aspects to car modding in which the motto “bigger is not always better” applies… well BBK upgrades are one of those aspects it applies to. When searching for a BBK setup one must focus on a setup that maintains as close as possible the same brake bias/balance the vehicle is designed with from the factory. A lot of the physics and specifications of the setup come into play here: number of pistons, size of pistons, size of rotors, and more. And if you’ve modified the weight of the car in front of centerline of car or rear of center line of the car it gets even more complicated because you’ve effectively changed the weights that the factory brake bias is based on.

Sometimes bigger kits are not always better because they may greatly upset the brake bias ratio that the car is designed with in mind for best braking results and safest car behavior under braking. And that’s just speaking of the front BBKs. When we start talking about rear BBKs you can almost guarantee that you’re going to throw off the brake bias unless your front setup is large enough to maintain the balance. If you have a pretty typical 4-piston BBK up front like the ST-40 which already maintains a close-to-factory brake bias, and then put a equally large BBK in the rear you’re creating much more rear-bias and greater braking power in the significantly lighter back end of the car which is very unbalanced and can lead to erratic behavior under braking like the back end locking up and getting squirmy well before the front end.

Making compromises on braking bias in the name of having larger brakes is pretty much NEVER a good idea, especially for a street car because you’ll rarely ever actually realize the true potential/reason for upgrading to bigger brakes in the first place: heat dissipation. As discussed in the previous section, the sole reason to upgrade the actual size of the brake components (aside from how they look) is that larger components can contain and dissipate more heat more effectively, meaning you have a deeper braking zone to dive into before brake fade. Frankly, for a street-only car, brake fade can be eliminated with proper pad choice and good brake fluid (flushed once a year). If you disagree with whether you’ll need the extra heat dissipation potential of a BBK on the street then at least consider it this way: there is NO reason to get a BBK if you’re only going to utilize it to its potential, say, 5% of the time you’re on the road, meanwhile throw off the factory brake bias 100% of the time you’re on the road (assuming you get a BBK that doesn’t have properly honed brake bias).

I could get into a lot more detail but the moral of the story is that a BBK is overkill - and sometimes counterproductive - for a street car but if you want to get one then before you just go nuts you want to make sure you’re taking into account factory brake bias (if your cars weight in front and rear of center line is close to factory) and choose a kit that respects the factory brake bias for best braking results and car behavior under braking. Just buying any setup without research into these considerations can end in less than optimal results. While you have to greatly upset brake bias to have very tangible and noticeably dangerous effects, even a minor upset in brake bias is not making the most out of your money because some of the returns you expect out of your purchase (in the form of braking performance) are being diminished and/or not capitalized on due to unbalanced setup. This is why I settled on the StopTech ST-40 BBK in front and NO upgrade to rear (aside from pads)… it wasn’t just the price of the kit, it was the fact that this kit for this application maintains close to VW Mk5/Mk6 generation brake bias (admittedly a bit skewed with the heavier/longer B6 Passat but still very close).


Notes about BBK / Wheel Fitment

I’m fairly confident there are no VW OEM wheels that can fit over even a modest BBK like the ST-40 I got. That said, typically you will need to get either aftermarket wheels with more generous offset and spacious spoke design, or you will need to get wheel spacers. At the time I didn’t want to part with my OEM Black Karthoum wheels so I elected to get spacers. These wheels were 18” X 8” w/ 51mm offset (“ET”). I originally purchased hub-centric ECS Tuning brand 15mm spacers for the rear and 10mm for the front, however, I ultimately wound up running 10mm spacers in the rear as well because with the 15mm spacers I had pretty bad tire rubbing on the wheel well liner (not the fender) on even pretty minor bumps in the road. Unfortunate because it looked fantastic. Almost perfectly flush (barely missed the fender when rubbing). With the 10mm spacers in the rear rubbing issues were rare (only on severe bumps) but I couldn’t get spacers any thinner than 10mm for the rear or front wheels would be spaced out further than the rear wheels which would look ridiculous. With the 10mm spacers in the front I had about 4mm of clearance from the caliper to inside of the spokes (generally you want to have no less than 3-4mm of clearance). The 10mm spacers in the front looked excellent too and never rubbed at all despite being very flush. This is because the front suspension does not have nearly as much travel (is much stiffer) than the rear.

I won’t belabor the subject of spacers because, in general, if one can avoid them one should; however, if you buy spacers make absolutely certain they are “hub-centric”. This means that the spacers have a pretty significant lip on them to fit the wheel over just like it fits over the factory hub lip. If they are not hub-centric then your wheels are, by default, now lug-centric which will wear out your wheel bearings in VERY short order (in the front anyway). It is hard to find hub-centric spacers in sizes smaller than 8mm. Not impossible, but harder. You must of course also get extended wheel bolts with spacers. The factory bolts are 24mm long so if you were to get 10mm spacers, for example, you’d want bolts that are 34mm long to safely secure your wheel and spacer to the hub.

I did not run spacers for long. A few months, maybe a bit more. But it wasn’t long before I decided that I didn’t like having rub to worry about in the rear, even though it was rare, and I wanted to get lighter wheels anyway. Lighter wheels means less rotational mass/weight and inertia that has to be overcome during acceleration and that has to be stopped during braking, which translates to better performance in both scenarios. I also wanted to get away from quite so much black. I still loved my OEM Black Karthoum wheels at heart, but it was time for something new… There will be more on that later though ;)
 

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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
Joined
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1,818 Posts
Discussion Starter #8 (Edited)
***Note: Late Spring 2017…


Lower and Tighter

It was finally time to tackle the most inherent problem of the Passat compared to its smaller/lighter VW brethren… the handling characteristics. The B6 Passat rides higher than its same-generation VW counterparts, is obviously heavier, and since it has the same sway bars, etc. there isn’t any compensation for all that in the suspension system. As a result, it has more body roll and understeer than the other models. With significant, and smart, modifications to the suspension this can all be negated to make the B6 Passat a surprisingly nimble car in its class and easily comparable to less thoroughly modified cars of the hatchback/2-door classes. While it is heavier than the GTI and Jetta of the same generation, it is not by much. This also makes it quite a good deal lighter than most makes of 4-door Sedan these days, so when comparing a B6 Passat to the sort of cars that it should rightfully be compared to it actually comes out looking pretty good.


Struts/shocks/springs

First things first, I wanted to lower the center of gravity, stiffen spring rates, etc. to counter body roll (and that disgusting fender gap). I wanted to lower the car enough to get significantly better handling but not far enough that I’d have concerns over complicated/un-ideal suspension geometry or cracking my oil pan due to the completely garbage roads in PA and surrounding areas. And, truthfully, I seem to be in the minority on this but I really can’t stand the look when the tire actually disappears behind the fender. I think it looks totally unattractive. To me, a perfectly flush look is the most attractive, so to that end I decided on about a 1.6” drop. Of course, that’s just my taste, to each their own.

Since I decided on a pretty mild lowering and since I knew I’d probably never bother with lowering it more than that, nor would I ever have a need to raise it again, I determined coilovers would be a waste of money. While I was initially going to get coilovers I eventually came to terms with the fact that, as nice as it would be to have the flexibility of adjusting ride height, I’d realistically be very unlikely to take advantage of it. The car wouldn’t be low enough to have problems in Winter (I still drove it in Winter sometimes back then) nor problems on even pretty awful roads so having to raise it was a non-concern. Plus if I did play with the ride-height based on seasons I’d technically want to get alignments every time I changed it which would get old and expensive fast. I’d also never buy cheap coilovers which meant I was automatically looking at $1200+ for coilovers and that was not worth it to me. Instead, I got the tried-and-true Koni Yellow struts/shocks and a set of Vogtland sport springs which allowed for that 1.6” drop I was after. My research also suggested that the spring rate of the Vogtland springs was a pretty good match with a set like Koni Yellows (e.g. on the more aggressive side). I set the Koni Yellows about 75% toward soft up front and almost full stiff in the rear. I would like to emphasize to my reader’s that one of the critical aspects to achieving the best combination of performance and ride quality when purchasing struts/shocks with separate lowering springs is a well-matched spring rate. This can take a lot of digging online and phone calls but the end result is worth it. If you choose wisely you will wind up with better ride and performance than just about any coilovers that are under roughly the $1500USD range for half the cost.

Koni Yellows, just like most sport struts/shocks/coilovers, are not intended to last particularly long compared to softer OEM-like setups so when I replace these after about ~30-40K miles of use I may opt for a higher-end setup. Then again, I’ve liked them quite a bit so far so I may just replace them with the same. That’ll be a discussion for a future post. Likewise, there is also a small possibility I may consider lowering to 1.8” lower because the 1.6” drop was not quite enough to get the perfectly flush look I wanted. It is close though so I have not made up my mind up yet on that either.


Strut mounts

I also installed 034Motorsport “street density” stiffer strut mounts at this time. These are replicas of the OEM strut mount design but made with a vulcanized rubber that is quite a bit stiffer than factory mounts which means less flex under the forces of cornering and, in general, a more planted feeling car, at the expense of ride comfort because bumps, grooves, and holes in the road will be quite a bit more jarring, even if you’ve got a very good setup otherwise.


End links

Finally, I installed SuperPro adjustable end links in front and rear. I was sure to install these with the vehicle resting at curb-weight, NOT in the air at all, because this is critical to making sure that the sway bars are not loaded up with any static pre-load. This ensures the most comfortable possible ride and most predictable characteristics. There isn’t a whole lot to be said about the SuperPro end links in and of themselves; they get the job done and are good enough quality. It is worth considering that they are one of the most affordable options, yet they have one of the best warranties in the business on their products. That was why I bought SuperPro end links. Aftermarket end links in aftermarket suspension applications aren’t known to last nearly as long as factory end links/factory suspension applications so you go through them pretty quickly, somewhat depending on driving style and typical road conditions. At time of writing, my front SuperPro end links have already been replaced once and lasted a bit under 2 years/~25K miles, but replacements were provided to me at no charge and will continue to be in the future thanks to SuperPro’s fantastic lifetime warranty. Once again I don’t have much in the way of pics of actual install or parts. I have one mid-install pic I grabbed for some reason with the OEM strut out and axle removed from the hub. And a picture of ride-height after install…


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***Note: Early Summer 2017…


Sway bars

Let’s start with the sway bar upgrades because the choice of sway bars is equally, if not more, critical as the choice of struts/shocks/springs or coilovers and I have quite a lot to dive into pertaining to that decision. Before I dive into sway bar specs themselves, let me begin by giving an overview of WHY to upgrade sway bars for any readers that may come along and are novices to this sort of thing. Sway bars are sometimes also called “stabilizer” bars or “anti-roll” bars and the latter of those two names gives us the best insight into their primary purpose; to increase roll stiffness/decrease body roll. The bars, of course, connect both sides of the suspension and thus transfer some force from one side to the other during cornering. This is torsional (twisting) force NOT compression and as the outside corner of the car experiencing the most lateral force twists up the opposite side of the car that is un-weighted tends to twist opposite; the torsional stiffness of the bar, it’s ability to resist that twisting, determines its ability to control body roll as these forces act on outside and inside of the car during cornering. What results from minimizing body roll is better ability to control wheel alignment in cornering and better ability to maintain traction/maximize the traction patch (amount of tire surface area) that has good contact with the road/track surface. Oh and, of course, to also adjust the propensity of the car to understeer/oversteer. Most folks know that factory VW cars (and indeed most non-performance cars, especially FWD ones) are setup intentionally to understeer. Understeering is as it sounds; it is when the car is not steering/responding as much as you are commanding or where you are pointing it to which results in you plowing through to the outside of a corner instead of having the clean line you were aiming for. Conversely, oversteer is when you get more rotation than you were aiming for because the back end has started to wander or, in more severe cases, completely kick out which can result in a classic spin out. Think of drifting as controlled oversteer and the concept is pretty easy to grasp. Oversteer preferred to understeer for performance driving; more so on RWD or AWD vehicles since they can actually take advantage of the oversteer and control it being that they have power to the rear wheels, however, it is still preferred oversteer before you understeer on a FWD car for performance driving. Ideally, though, for performance driving (especially in a FWD car) you want it to be pretty neutral. If it’s going to do either you’d rather it oversteer a bit first as a warning but you really want it to be pretty hard for either to happen so that you can take the car to a pretty extreme limit before you induce either. And that is the intention I had when I chose my sway bars.

There are a lot of people get caught up entirely in the numbers when it comes to sway bar choices, as in the measurement (in millimeters) of the bar. While this is important, as it directly correlates to that torsional stiffness mentioned earlier, it is not all-important. Nor is the construction of the bar (hollow vs. solid), material strength, etc. technically speaking. What is all-important is actually at a higher level than all of those particulars; it is simply bearing in mind the stiffness increase of the front and rear bar IN RELATION to its factory counterpart (and how you do that effectively is by knowing those other specs). So many people gloss over this understanding. They hear that getting a stiff sway bar in the rear is how you get rid of understeer and encourage oversteer first, so they get a huge 27mm rear sway bar and don’t upgrade the front sway bar at all, or very little. My personal favorite, though, is the guys who follow that “logic” even further and actually remove the front sway bar entirely, whilst fitting a huge rear sway bar. All of the above are VERY ill-advised. By doing so, they are stiffening the rear by a factor of ~5x or more and doing nothing for the front. This does not encourage neutral handling, this greatly increases propensity to oversteer way earlier/easier than one should, which is just plainly foolish on a FWD car (or any car intended for true performance driving, as opposed to sliding/drifting). Furthermore, many folks underestimate the importance of the front sway bar. Many folks view the front sway bar as THE thing that creates understeer. While technically not wrong, it’s not that simple. In fact, when everything else is properly setup in relation to the front sway bar (there’s that word again – everything is “in relation to” when it comes to suspensions), the front sway bar will actually reduce overall roll much more than the rear sway (because roll is lateral momentum and there is significantly more weight in the front), will improve steering (turn-in feel and responsiveness), and making your car more stable WITHOUT increasing understeer propensity. This then means that running a fairly stiff front sway bar is generally a good idea, but that you then must compensate for this enough when stiffening up the back end in relation to the front end and in relation to its own rear-end factory stiffness setup (or else, yes, you will cause more understeer and somewhat poorer traction in the front, particularly on bad roads).

Again the key is to upgrade the sway bars in relation to the factory setup. So we must then know what the factory sway bar specs are, right? Well on a B6 Passat (and all Mk5 platforms) the front sway bar is a hollow 23.6mm diameter bar and the rear sway bar is a hollow 21mm diameter bar. In addition to being hollow they are also of fairly weak construction. It is not unheard of to sheer one in half from exuberant driving at a track. So how do we make our upgrade choices, in relation to the factory setup, to accurately create a setup that is neutral or slightly prone to oversteer? Well, we have our baseline specs for the factory setup so we need to do some heavy research on the aftermarket options and compare. Alternately, you could just keep reading because I’ve already done that ;). I eventually settled on a solid H&R 26mm front sway bar (set to soft) and a solid H&R 24mm rear sway set to hard. Based on significant research and phone calls I determined that the best approximation of the torsional stiffness increase of these bars compared to stock is a 130% increase in torsional stiffness to the front and a 270% increase to torsional stiffness in the rear. This highlights my earlier point about people who haphazardly upgrade to a very stiff rear sway bar without consideration to the front because they are solely focused on the measurement of the bar not the actual proportional increase in torsional stiffness in relation to the rest. Notice that my front bar has a larger diameter than the rear bar, yet the torsional stiffness in the rear is now quite a bit higher than the front is (even after taking in to account the fact that the front was originally stiffer on the factory setup). This is pretty much the ideal outcome. While I could potentially go a little stiffer in the rear without changing the front, or go a good deal stiffer in the rear while also increasing front stiffness proportionally, I have found no need and it is ill-advised to get carried away with increasing torsional stiffness. If you increase the stiffness too much it will start to reduce the independence of the suspension on either side of the vehicle during cornering and this is when you run the risk of actually reducing traction because when one end breaks loose it basically brings the other end with it OR, in the opposite case, if the outside rear tire has so much lateral force on it but IS able to maintain traction then the inside rear tire actually lifts off the ground which puts that much more strain on the traction abilities of the rest of the 3 tires still planted.

Anyway, what has making all of the above considerations and choosing my sway bar setup accordingly meant for my car? It means I have reaped the full benefits that a stiffer front sway bar can provide on a front-engined, FWD car while ALSO dialing OUT understeering in favor of a more neutral handling car with a slight tendency to oversteer instead when I’ve pushed it to an extreme limit (which serves as a good warning that will not rob performance driving as much and can be fun). This setup has made my Passat significantly more nimble and capable on the track than most people would ever expect of such a car and it absolutely demolishes back and mountain roads. It is very balanced and very fun!


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Front Lower Control Arms/Polyurethane Bushings

For those of us with B6 Passats we actually have a leg up on our fellow enthusiasts with Mk5 platforms in this area because the B6 Passat aluminum front lower control arms (LCAs) are actually quite a bit lighter than the stamped steel front LCAs of the Mk5 platforms. This is important because control arms (along with wheels, brake components, spindles/hubs, and plenty more) represent “unsprung” weight. The less unsprung weight the quicker your primary suspension, your struts/springs or coilovers, can react to ever-changing circumstances while driving and thus the better job they can do in keeping the tires maximally engaged with the road surface. Lower unsprung weight also contributes to sharper steering response and turn-in. So buying lightweight aluminum front LCAs is something we B6ers don’t need to do. In fact, Mk5 owners looking to minimize unsprung weight often replace theirs with B6 Passat front LCAs. They will also buy B6 Passat spindles because ours are also lighter weight. Replacing their front LCAs with those from B6 Passats is far cheaper than buying SuperPro’s front LCAs with polyurethane bushings pre-installed; I’m fairly certain that SuperPro’s front LCAs are literally B6 Passat aluminum front LCAs that have been polished for a high-luster haha. If they are any different the weight difference s negligible. I’ve actually compared them side-by-side. Not with a scale, but by hand, which is better than nothing. Anyway, point is, starting with lighter weight aluminum front LCAs is preferable and since I have a B6 I already had that covered. So all I had to do was buy the SuperPro polyurethane bushings that fit to the front position and the rear position (the bracket that bolts to the subframe). The latter of which had to be pressed into the bracket housing.

Not only are these bushings void-free, unlike the factory bushings, but they are significantly stiffer than the factory bushings, by some margin. I am fairly certain that they account for a decent bit of the stiffness/harshness the car has when encountering sharp bumps or divits in the road. However stiffening these bushings is fairly critical to performance in just about every area because these bushings, particularly the rearward one within the bracket bolted to the subframe, receive weight transfer from the car at pretty much every axis of movement; during acceleration and braking and during lateral movement while cornering. Therefore, stiffening these parts will contribute to more consistent and controlled reaction from the suspension system under changing conditions which will allow for some improvement in traction during acceleration/braking, but more so it will improve steering responsiveness and turn-in quite a bit. In effect, these bushings are SuperPro’s version of the popular WALK bushings (Whiteline Anti-lift Kit). They accomplish pretty much the same thing except SuperPro’s are a significantly cheaper option, are just as high quality (if not higher quality), and come with an unbeatable warranty.

One nuance to the above described benefits of the SuperPro polyurethane bushings for the front LCAs (again it’s particularly the rearward one in the bracket that bolts to the subframe), is that those performance advantages that I described are not just achieved by the actual stiffness of the bushings but also the fact that, like the WALK kit, those SuperPro bushings increase positive caster. Caster is one of the 3 main wheel/suspension alignment measurements/specifications. It is the least talked about typically. Most people understand what camber is, at least at a basic level, if nothing else thanks to the folks who drive around with wheels/tires on a significant slant (negative camber), and most people know about toe because bad toe alignment leads to the car wandering on the road instead of driving straight, as well as poor tire tread wear. But most people know very little about caster. I’m not an expert either, but I can explain the fundamentals. The best way I know how is with a visual explanation. If camber were depicted by drawing a vertical line down the middle of each tire while looking straight on the front of the vehicle and camber was negative if the top of that line slanted inward on each side (positive for the reverse), then caster is the same if you were to draw that line down the middle of the wheel/tire while looking at the car from the side; positive caster would be if you tilted the top of that line towards the rear of the car (and positive would be the reverse). Positive caster is always preferred for performance driving. Just like the other alignment specifications, it is measure in degrees. If I recall correctly, the factory caster specification for the front of the B6 Passat (and likely the Mk5 platforms as well) is approx. 7* of positive caster. The SuperPro front LCA bushing that is pressed into the bracket that bolts to the subframe can be purchased in a version that does not increase caster or can be purchased in a version that does increase caster. The degree to which the latter will increase caster depends on what orientation the bushing is pressed in at, as the hole in which the front LCA itself inserts is offset somewhat from the center. The bushing allows for a maximum of 1.5* more positive caster. This is enough to make some noticeable changes to driving/handling dynamics. More positive caster will typically increase steering effort which is, of course, something typically favored by driving enthusiasts, though not necessarily advantageous in and of itself. It will also, however, improve suspension reaction and steering stability at higher speeds and, most importantly, increase the steering angle which for better tire lean (better traction) in cornering.

Those are all the upsides of the SuperPro front LCA bushings. There are some downsides. Apart from the fact that they increase stiffness and decrease ride comfort, as already mentioned, they also should be serviced (lubricated) periodically. Technically they do not NEED to be but they should be. Again, this is particularly the rearward bushing that is contained in the bracket that bolts to the subframe. It can be serviced without removing the control arm itself. You can unbolt the bracket and slide it off the end of the control arm. This is handy since you then won’t have to worry about getting an alignment done just for servicing these bushings. You just want to lubricate them with some good synthetic silicone or lithium grease. If you live in an area where it gets below 40*F these bushings will make some creaking noises until they’ve been stretched out/warmed up a bit. If they’ve been serviced recently they may not creak until slightly lower temperatures. But if you live in an area where it gets below 20*F they’re going to creak no matter what and lubrication will only reduce it. It’s not that bad if they are lubricated. I find it perfectly tolerable given the benefits they bring to the table but, as I mentioned in one of my earlier posts, I’ve become less anal about these kind of things over the last couple years than I was originally. The thrill of driving a car that performs to the max outweighs the annoyances of creaks, vibrations, etc. as long as they aren’t very, very distracting or omnipresent.


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Subframe Bolts & Locking Collars

I bought the TyrolSport “deadest” subframe bolt/collar kit. There is a similar kit available from CTS Turbo for quite a bit less, even with the ARP bolts included (more on that later). Frankly they are probably pretty comparable but the collars on the TyrolSport kit seemed beefier and that was what swayed my decision (will also explain why shortly).

First let me explain the principle behind this kit. Due to the significant forces exerted on the subframe during driving, especially over bumps or holes in the road, and the fact that the shaft of the stretch bolts used to secure this subframe to the chassis are not actually as wide as the shaft of the subframe they pass through to reach the chassis, the subframe itself can shift somewhat if enough force is exerted on it. This will affect camber, and to an extent caster, alignment specifications. However, these issues only occur in extreme circumstances, like if you hit a significant pothole; more often, the subframe just flexes a bit momentarily. This causes a well-known clunking noise that many B6 and Mk5 platforms have and which VW released a technical service bulletin (TSB) for. It can also allow for some loss of feedback and responsiveness in the steering and overall planted-ness (if that is a word?) of the car since the subframe is connected to steering components.

This TyrolSport (or CTS) “deadest” kit is designed to eliminate that. It does so by provided bolt collars for the head of the bolts and the shafts of the bolts where they meet the chassis to bolt the subframe to it. The TyrolSport collars look beefier, as in they seem to be machined to tighter specifications and perhaps fill in the shafts, thus locating the bolts, better. This is speculation based on the pictures provided by each company for their respective products. I have not actually compared them side-by-side, physically, in-person. The TyrolSport kit includes APR bolts, whereas the CTS Turbo kit comes with them as an option. ARP bolts are specially machined bolts with significantly higher torsional, tension, and compression tolerances, than the factory bolts. They do not stretch whatsoever, unlike the factory bolts, so they can be removed and reused infinitely with no concern. You only really need ARP bolts for the rearmost bolts for the subframe as these bolts receive the brunt of the forces on the subframe and are most responsible for locating the subframe correctly, evident in the fact that VW took care to use special bolts for this location too (though not like ARP bolts).

To be clear, installing this “mod” is unnecessary unless you have that subframe clunk and can’t stand it. I think it makes a slight difference in the areas described above, and it definitely does get rid of that clunk, but otherwise it is passable on its own; however, if you are dropping the subframe anyway, to install a front sway bar or subframe dogbone mounts (coming up), then you may as well install this mod too.


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Subframe Dogbone Mounts/”Pucks”

I am going to refer to the subframe dogbone mounts as “pucks” not “mounts” since it describes what they look like well and there is also a subframe dogbone pendulum bar which connects between the two subframe dogbone “pucks” so the terminology can get a bit confusing if they are both referred to as “mounts”. I generally also refer to the dogbone pendulum bar as a dogbone pendulum “bar” to better describe what it is and avoid confusion.

Let me also bring up another term I’ll be throwing around a lot in this section: NVH. This stands for “noise, vibrations, and harshness” and it basically described the elephant in the room when it comes to upgrading these kind of parts. I touched on NVH briefly in one of my previous sections regarding the 034 Motorsport’s street density engine/trans mounts that I installed. Well, they didn’t make a significant impact on NVH but that is quite simply not the case here. You cannot get away with upgrading these subframe dogbone pucks without, at best, a moderate increase in NVH. The increase in NVH varies quite a bit based on what upgrade option you choose. Another thing that will determine how much of an increase in NVH you have is whether you have a manual trans or a Tiptronic/DSG trans; the auto trans vibrate a lot more to begin with and ANY upgrades to the subframe dogbone pucks will magnify that quite a bit so, for this reason, auto trans owners will experience much more increase in NVH with ANY upgrades to the subframe dogbone pucks.

Let’s start with the basics – why upgrade these dogbone pucks? – for those who are new to modding. Well, it’s actually one of the simpler explanations I’ll cover in this whole section. You upgrade them because the transmission and, therefore, to an extent, the engine itself is linked to them via the subframe dogbone pendulum bar. This means that if you stiffen the dogbone pucks you will reduce movement in the trans and engine. This means less wheel hop under acceleration, less lurch under braking, less lean during cornering, and also less trans/engine lurch when releasing the throttle (particularly nice when you are shifting if you have a manual trans).

I had a few paragraphs written on many different options to choose from for this upgrade but sadly this post exceeded the maximum allowed characters and that info was first on the chopping block since it didn't really directly pertain to my build. I'd be MORE than happy to add it in a follow-up post later at request though (saved in word doc for the thread). As for my choice: I chose the VWR dogbone pucks. These are literally aluminum pucks with a few rings/layers of polyurethane throughout the center to distribute and absorb some vibrations. And, yes, there are two of them; they do replace BOTH of the factory dogbone pucks, which means you do have to remove (or at least lower) the subframe to install the upper puck replacement. Due to their design and, of course, the fact that they replace BOTH of the factory pucks, they increase the stiffness, and thus the performance properties I described earlier, significantly. Let me put it this way: after I installed them, the amount by which transmission movement was decreased literally affected my clutch engagement point/behavior, particularly when starting out moving in first gear. There was suddenly even less margin for error/smaller window of pedal travel in which to apply throttle and take off in first gear than there already was with my sporty and stiff upgraded clutch/pressure plate. As you can imagine, the NVH increase was pretty substantial, but what you might not have expected is that it as wasn’t THAT bad! That’s because it was more situational than anything. It was NOT a constant, omnipresent increase in NVH when just sitting idling the car. In fact, it was really only noticeable during certain actions, like when operating the clutch to start out in first gear as mentioned, or like when turning the AC on because that creates additional load on the engine, transmitted through the trans which is of course linked to these upgraded pucks and the subframe itself. Those are really the only 2 instances in which I noticed much difference. It was a pretty significant difference to be fair, but since it was only in those instances I was not all that bothered. It also got slightly less severe overtime oddly. I was not expecting these particular pucks, due to their design, to “break-in” but I believe they did to an extent. I also probably go more tolerant of it with time, which can never be overstated.

Let me, again, emphasize though that the above will NOT be your experience if you have an auto trans; I strongly suspect that these will be quite a bit less civil if you have an auto trans. I also want to emphasize that, as explained in a previous section, I currently have an upgraded clutch kit designed to work with a factory dual mass flywheel (or in my case the Mk6 Golf R factory DMF). While explaining the design of the factory DMF is not really in the scope of this section, suffice it to say that it is essentially two flywheels bolted together with two large springs set around most of the internal circumference, and these springs compress as the flywheels spin during operation; the springs compression to absorb and dampen torsional forces and thus vibrations that would otherwise be felt in the car. Why am I bringing this up? Because my DMF is likely absorbing some of what would otherwise be increased NVH caused by the VWR subframe dogbone pucks. I don’t think it is a particularly large factor and this doesn’t mean I wouldn’t recommend them to someone with a single mass flywheel (SMF) setup, but it is something to bear in mind as it is a factor. Lastly I would like to emphasize that I think NVH in the cabin will be worse in a Mk5 platform because the interior fit/finish/quality is better on the B6 Passat. It makes mods like these more reasonable.

I’ll end this section by pointing out a general caution. Stiffening these subframe dogbone pucks (and also the subframe dogbone pendulum bar itself) contribute particularly highly to increasing the vibrations that the transmission internals themselves experience. While nobody knows just to what extent this can actually cause harm over time, it is possible that it could contribute to shortening the life of certain parts. One part in particular I am virtually positive would be have a shortened lifespan due to this mod is the factory DMF for reasons that should be very clear based on the brief explanation of its function earlier in this section.


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The Result

All-in-all I’m pleased with the performance of this setup. The ride is definitely on the stiff side when encountering sharp bumps or divits in the road but it’s certainly tolerable. In all other road conditions/situations besides sharp bumps, this suspension setup is smooth and refined and leaves little to be desired. In fact, for a little while I was thinking it was stiff or not as refined as I was hoping but I’ve been in plenty of other setups on VWs since and pretty much every time I INSTANTLY re-appreciated my setup for its refinement. It’s the kind of ride that feels like it “belongs” if it were targeted to be a sportier, higher performance car than it is; whereas, a lot of other VWs I’ve been in have a ride quality and behaviors/noises that feel “out-of-place”, like they’ve obviously been modified (and not necessarily well). I believe that difference is attributed to all of the finer points of choosing suspension modifications that I have considered in my setup. All of these mods have performed as expected; they’ve contributed to tightening up the car and massively reducing body roll, tightened up steering response & feedback, steering turn-in, traction in all circumstances, and the pleasure of rowing through the gears, to the point where it is an absolute thrill to take this family sedan down back roads and a variety of twisties with surprising amounts of composure and speed. It is truly one of the things I enjoy doing most and I NEVER do not thoroughly enjoy driving this car!
 

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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #9 (Edited)
Miscellaneous Mods/Parts


***Note: This post does not fit into an exact chronological time-frame as I frankly forget when exactly I did most of the below; these miscellaneous/minor items occurred over the course of the last few years




New shoes… Again, Again

I wouldn’t really classify it as a mod but I’ll kick this section off with the wheels I eventually replaced my OEM Black Karthoum wheels with. I really did like the Karthoum wheels but I wanted to get away from so much black and I wanted something that weighed less and had sufficient clearance for the calipers without the need for spacers. I chose Enkei M52 in “hyperblack” which apparently means a medium-silver shade to Enkei. Whatever it is, I love it. I really like the spoke design of these wheels. I like the fact that they are fairly light for an affordable 18” cast wheel (21lbs). These are 18x8” w/ ET45mm. Enkei has great quality finishes, a good range of wheels for any budget, and they are very strong for wheels in the price range of even their budget options. Most of their affordable wheels, like these M52, are typical gravity or low pressure cast in most areas but the areas that are most critical like the wheel lips and outer edge of the barrel are formed via rotary flow casting which yields similar strength as a forged wheel in those critical areas. By focusing on only those areas that really need the re-enforcement they keep the costs down but retain a strong wheel.


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Depo Smoked black front bumper side markers/indicators

For the longest time I held off on replacing the ugly/distracting orange front bumper side markers/indicators. I had no reason at all for holding off other than that it just wasn’t really a priority (as a rule aesthetics aren’t a priority for me in general), but considering how cheap and easy they are to replace I wish I had prioritized them much sooner because, despite being so simple, they transformed the front-end of the car.

There are a few different brand offerings out there for these, I went with Depo. Depo (using Helix as their distributor name) makes plenty of OE lights for VW/Audi so I trusted the quality. I replaced the factory bulbs with orange bulbs so that they could still function as turning indicators too.


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BSH Throttle Pipe

In truth, this was an impulse buy and nothing more. I didn’t expect anything particularly impressive, if at all, out of it and that’s pretty much exactly what I got. It was a cheap mod and stood at least some chance of improving throttle response and/or spool somewhat so I figured: “why not?” It comes with an integrated bung for DV relocation but I never made use of that while I was K03 (I preferred to keep the stock location) and, on my new turbo, I now prefer my relocation via a custom intake-to-turbo inlet junction pipe for the same reason: it keeps the DV boost recirculation action as close to turbo and intake as possible. The only feature of the BSH throttle pipe I may ever take advantage of is the integrated water-meth bung but even that is unlikely: if I need the extra fueling later down the road I will likely add a fifth port injector (more on all that in a future post on my big turbo setup, etc.). This mod does very little. I don’t recall noticing any difference from it, but then again I installed it nearly 3 years ago. Still, if it made any difference, it was negligible.


Spulen Silicone Brake Booster Hoses

I had one of those notoriously brittle brake booster/vac pump hoses crack on me a couple years ago. I decided to be lazy and instead of finding a local store to buy silicone hose for cheap from I ordered the pre-formed Spulen silicone hoses for this exact application. They are quality silicone hoses and they fit just right. Not much else to be said. Well, except that while I was replacing them the damned coolant flange that doubles as a vacuum hose pass-through down under the vacuum pump on the side of the block decided to crack when I removed the factory hose connection so I just bypassed it with hose barb fittings and routed directly to the brake booster, as seen below:


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Go Fast Bits (GFB) DV+

I’ve had the GFB DV+ for 3 years now on both my stock turbo setup and now my GTX2867R setup. I’ve also spoken at length with Brett from GFB (the engineer behind it) on both his product and many other subjects. I have quite a lot to say about Go Fast Bits/Brett and the DV+. First things first, Brett is a top-rate guy. Very knowledgeable, very personable, and very kind with his time. He let me pick his brain on many subjects. He's also very honest and, believe it or not, he’d be the first to agree with the not so well-known statements I’m about to make about the GFB DV+ below; in fact, the literature you get with the GFB itself will attest to exactly the following…

The GFB makes negligible performance improvement IF you already had a totally properly functioning (fully sealing) factory DV. The folks who get the GFB and say it made their cars faster or whatever are either suffering from a form of placebo effect or they had a DV that was leaking an itty bit (neither of which is uncommon). While the Rev D piston style DV is far more reliable than the old Rev G diaphragm style DV, it can develop minor leaking where the piston should seal. This is usually due to either age/wear or heavy abuse on setups running in excess of 26+ PSI. As for the GFB, the only technical performance advantage to it is that the progressive nature of the piston opening/closing as compared to the stock DV's binary (full open or full closed) nature, allows the GFB to keep sliiiightly more boost between shifts so when you're back on the throttle you get to full spool ever so slightly faster. On a K03 that spools almost immediately anyway this matters very little as it might shave off a 1/10th of a second of spool time, maybe. I track my car so I'm attentive to these things and I didn't notice a thing. I didn't even notice a difference before and after when I put it on my GTX2867R which obviously spools slower; but there were a couple other changes I made around that time too so it wasn't a perfect before/after test.

Bottom line: The GFB is a great product. It's well designed, it's clever, and it is made by a cool company. But the reason to buy is not for performance gains, it is because it is durable and you will not have to replace the DV ever again, even if you upgrade to a turbo that will make much more boost.

One more note: the GFB can trip up certain custom tuning software and throw boost-related CELs and behavior issues, probably because they don’t expect the result of the progressive nature of the GFB’s main spring/piston. I encountered this issue after upgrading my turbo and having a custom tune written by United Motorsport. The solution is simple: remove the main spring and the GFB unit will behave in the same binary full-open/full-closed way as the factory unit but will, of course, be stronger.

Now a more general note on DVs VS. Blow-off Valves: DO NOT run a blow off valve. They do nothing except make noise. They act much slower than electronic diverter valves and the ECU expects an electronic diverter valve for calculations it makes. The stock rev D diverter valve can hold the boost of a stage 1-2 tune and even some stage 3 just fine. If for some reason you want to upgrade anyway, replace it with a GFB to retain ECU control over the valve but to be stronger than stock. The reason you want to maintain the ECU electronic pulse-width modulation control over a DV unit (stock or GFB only) is because when the throttle valve closes and the motor is in overrun (translation: when you let off the throttle at WOT/high revs) back pressure develops in the turbo housing which reduces speed of the turbine and increases turbo lag for when you get back on the throttle. To combat this, the DV is opened by an electrical actuator which allows the air to blow back to the intake side to the turbine and maintain turbine speed. Then when the throttle valve reopens (when you hit the go pedal) the DV closes. These behaviors COMPLETELY rely on the pulse-width modulation (PMW) electrical signal from the ECU to operate correctly and that ONLY happens with the stock DV or the GFB DV+… so moral of the story is when you get a BOV or an analogue DV that doesn’t retain the connection to the ECU, you are robbing yourself of that design and performance/turbo spool advantage with the regular DV or GFB.


Spark Plugs/Coil Packs

I used NGK BKR7E and BKR7EIX plugs (experimented with gaps @ between 0.026-0.032) up until very recently. I used them while I was on stage 2 tuning with factory turbo and also for some time after I had my GTX2867R setup. I’ve recently switched to BKR8E. I’m not going to belabor this subject… I think everyone in this community knows by now that if you’re tuned you run 1-step colder plugs and if you’re stage 3 BT (not K04) you may consider running 2-step colder plugs, blah blah. And you should lower the gap on your plugs, blah blah.

Frankly none of this is, strictly speaking, necessary if you have a good tune and good engine running conditions as-is. A stage 1, stage2, or even K04 equipped VW will not run the risk of overheating even the stock 6-heat range plugs although it is definitely more ideal for to run the step colder (7-heat range) plug especially in the case of a K04 setup. You do NOT want to go 2 steps colder unless you’re running a high powered BT setup with a lot of boost and cylinder pressures. The cost of running a plug that is TOO COLD is that deposits will develop and eventually spark strength will suffer. 1 or 2-step colder plugs are just extra icing on the cake to help with the combustion temps as these plugs can resist heat better which will contribute to stronger spark and reduced combustion temps.

What is probably just as, or more, important to note is something not so many people realize about the spark plug electrode materials used. A lot of people assume that the Iridium plugs are the highest performing since they are by far the most expensive. Not the case. You’re just paying for the fact that iridium is a more expensive rare metal and that these plugs last longer. Copper is actually the strongest conductor out of the 4 plug electrode materials (nickel, platinum, iridium, and of course copper). The NGK plugs ending in “E” (e.g. BKR8E) are the copper-cored plugs; the ones ending in “IX” are the iridium-cored plugs. Both are great. All of the above aspects of choosing plugs for tuned VWs are not obligatory, they are just more or less ideal.

The story is pretty similar when it comes to the R8 red-top coil packs. These coil packs do technically produce a stronger current (resistance is 5.3ohms compared to around 3.3ohms for stock coils), but this difference is negligible in just about any setup. Actually, running the R8 coils makes it MORE important to run a lower plug gap due to that higher resistance. But in any event, it would take a much more heavily modified setup than even mine to stand to benefit from the R8 coil packs on their own merits. Otherwise the coil packs are effectively the same. They are no more or less reliable than the NEWEST revision of OEM black-top plugs (but they are much more reliable than the older revisions).


TyrolSport Master Cylinder Brace

In the quest for even firmer and consistent brake pedal feel/feedback to prepare for track days I decided to install the TyrolSport master cylinder brace. I was aware of this mod long before I finally decided to install it; what swayed me was a good friend and track enthusiast’s positive feedback on it.

Unfortunately, after installing, I must say my feedback is NOT positive and I wish I had continued to take a pass on it. Long story made short, I got very little noticeable improvement from it. HOWEVER, it is important to recognize that my friend has a Mk6 GTI and I have confirmed by observational testing, on a couple different cars as a test sample, that far more flex occurs for the master cylinder of the Mk5/Mk6 under brake application/master cylinder piston travel than does on the B6 Passat; in fact it is minimal on the B6 Passat. This accounts for why my friend raved about the brace and I found it very underwhelming. I only thought to test this after the fact though and I had to make some modifications to the bracket (more on that in a moment) so I can’t return it. Figure I may as well just keep it for whatever small good it may do.

I should make an IMPORTANT NOTE for anyone considering the TyrolSport master cylinder brace with an APR short shifter kit… you will need to modify the TyrolSport brace by cutting off a corner of it to allow the APR side-to-side shift relay full range of motion. The APR short shifter kit is unique in that it is the only (that I’m aware of) short shift kit that has a side-to-side throw reduction via replacing the side-to-side shift relay as well. The APR side-to-side shift relay is chunkier than the factory one and during shifting it will get caught on the TyrolSport master cylinder brace, completely prohibiting you from shifting properly. The solution is simply to use an angle grinder or similar to cut off a portion of the master cylinder brace. This modification in no way interferes with how the brace is installed nor how it functions. See the pics below…


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Custom Bracket For CAI

This one doesn’t really warrant any pictures or special attention, I’m only bringing it up for whatever good the subject may do for readers because I’m not the only one who’s run into issues in which the cold air intake pipe will smack a hard-line to the master brake cylinder when hitting bumps or during heavy braking. When this happens the feedback can be felt through the brake pedal and it is very annoying. Lots of people confuse it for issues with their brake booster and such. Some companies include a bracket with their CAI kits to prevent this. The Forge “Wintake” did not so I just fashioned my own using some basic items from the hardware store and taking advantage of the unused bolt hole that VW kindly provided on the factory battery tray. So if you are reading this and you have strange vibrations through your brake pedal under heavy braking or especially when on bumpy roads, it might be your CAI pipe smacking your master cylinder…


Integrated Engineering Billet Aluminum Valve Cover & Catch Can Kit

This was probably one of my more lavish and unnecessary purchases, but only in retrospect. At the time that I installed the IE billet aluminum valve cover (which necessitated a different catch can setup than what was my current BSH setup), I had a practical reason for doing so. Sometime in early 2017 my motor began developing the classic rapid oil burn issue that the FSI platforms are known for (to the tune of 1 liter per 1K miles, or worse, depending on how I drive – more boost means more burn). I am going to discuss the several different causes of rapid oil burn on the FSI in detail later on under the “Miscellaneous Maintenance” heading, but for now I will just say that I had already ruled out a couple of the simpler causes and the next cheapest/easiest one to rule out was the valve cover itself. This is because the factory valve cover for the FSI motor has an internal plate/seal that is designed to prevent oil from inside the head from being sucked into the passageway/channel that travels from the front PCV to through the valve cover (internally) and back to the rear PCV. If this internal plate/seal fails then the pressure in the PCV system will suck oil into it and down through your boost loop. What oil remains after it passes through the turbo and intercooler will burn up on your intake valves.

So, that said, I was facing getting a new valve cover as my next step to continue ruling things out. I basically figured I may as well upgrade it to the IE billet aluminum one because it completely deletes the front PCV and rear PCV locations, thus eliminating any possibility of the issue I explained above.

The IE valve cover functions only as a valve cover and, therefore, requires rerouting of the PCV and catch can setup quite a bit, hence why IE has a version of their catch can kit that is designed for their valve cover too. It is worth noting that if you already have a basic catch can setup for the factory valve cover then switching over to the IE valve cover does not necessarily require you to buy their catch can setup specifically for their valve cover; you can absolutely customizing your existing setup with parts from the auto store. This would entail finding the proper AN fittings/joints/junctions, hoses, clamps, etc. to run a hose from the IE valve cover outlet on the top and another from the top of the oil filter housing assembly together into a T-junction with a outlet hose that then runs to the catch can; the catch can then has an outlet hose that runs to the turbo inlet (where the factory rear PCV breather used to connect).

I decided it would be much simpler and look much cleaner to pony up the money and just buy the IE catch can setup.

You’re probably wondering if my oil burning issue was resolved… NOPE. But I had to find out if the factory valve cover was the issue one way or the other and this was the most surefire way to do so and also upgrade to one that I could more readily trust to hold up long-term to the increased heat and pressure that would result from the eventually turbo upgrade that I was planning for eventually. Without further ado, here are some pics…



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BSH Heatshield For CAI & Engine Bay Cosmetics

I wanted to replace the teeny factory heatshield between the exhaust manifold and Forge CAI with a larger and nicer looking heatshield so I picked up the BSH powdercoated heatshield which probably does a marginally better job at deflecting heat from the CAI due to its larger size (it stretches all the way back to the firewall). The effects of these kind of heat shields are probably not all that significant; the engine bay is going to get hot and parts are going to heatsoak when you come to a stop regardless. I did not test before-and-after intake air temps so I don’t know if this BSH heatshield makes any difference at all but it can’t hurt. I imagine it would be quite a bit more effective to wrap the CAI pipe in heat reflective wrap, which I will likely do in the near future.

I also picked up the Porsche 911 coolant reservoir cap and an ECS black anodized aluminum oil dipstick to clean up the engine bay a bit. The blue factory coolant reservoir cap and orange factory dipstick are quite distracting. The dipstick tube itself remains orange and I may paint it at some point but it isn’t nearly as noticeable/distracting as the dipstick itself was. I’m not generally one for cosmetics which is why it took me awhile to get around to these but eventually some things need to be done haha.

The coolant reservoir cap and the oil dipstick can be seen in the pics from the above section about the IE valve cover/catch can setup. The BSH heatshield can be seen installed below


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Magnetic Drain Plugs for Engine Oil Pan and Transmission Drain Port

These hardly warrant a section, I’m just mentioning them because of my dedication to being comprehensive in this build thread. May as well not ruin it now. I think the purpose of these is pretty clear, the magnets help pull out tiny metal shavings in the oil from normal engine/trans wear so that they don’t get circulated and cause additional wear. I bought Dimple brand magnetic drain plugs that I read about on Ryan Jacob’s build thread. They are supposed to use much stronger magnets than your average cheap magnetic drain plugs. I tested this and it appears to be true. How big of a difference this really makes in the application itself is hard to say. It can’t hurt and they definitely do pull stuff out of the oil. Whatever good they can do is worth the few extra bucks.


Vantrue N2 Front/Rear Dash Camera & Power Management System

I eventually picked up a dash camera. There are no shortage of reasons for having a dash cam on-board; not only can you record those more adventurous drives and hang on to them but obviously it is very useful to have something that can prove irrefutably that you were not at fault in an accident or that somebody hit-and-ran in a parking lot or similar.

To be able to perform well in all these scenarios the dash cam would need to having a “parking mode” (motion/sound triggered recording while car is off), have as close as possible to 360 degree coverage, have high resolution recording, and have decent night vision. It would also have to be fairly inconspicuous and be able to be wired stealthily. Lastly, there would need to be a system in place that would prevent the cars battery from being drained past a certain point when the car is parked and the dash cam is set to record events (motion or sound triggered).

The Vantrue N2 camera, paired with the VicoVation Power Plus management system, were the perfect answers to all of these needs. The Vantrue has a forward and rearward facing camera on the same device/body (not a separate secondary rearward camera like many others). This was a large part of why I chose this camera; I did not want to tear up my perfect-condition headliner to run power cables to separate camera in the rear of the car. Another advantage to the rearward facing camera being on the dash cam itself is that it gives a much wider degree of recording coverage from that location since it can see out the side windows too. The downside, though, is that it doesn’t have quite as good of a view out the rear windshield, but it is still perfectly sufficient to prove if someone was driving recklessly behind you or to have a recording of your friend eating your dust in a race haha.

The Vantrue also records in 1440p resolution (if only front camera is enabled) and 1080p resolution if both are enabled. The camera records at 30 frames per second. These are pretty great recording specs for a little camera. I’ll say that preferably the FPS would be 60 instead of 30 but that would be asking a lot. Not many dash cameras record at 60 FPS and the ones that do are even more expensive than this one already is and don’t have some of the other features I liked. It also features infrared night vision. The quality of the night vision is not phenomenal but it is definitely sufficient.

The intelligent “parking mode” allows the camera to detect motion (it is very sensitive and accurate to the slightest movement at surprisingly long distances) and also detect sound or vibrations near the car. Any of these events trigger the camera to record front and rear video for a configurable duration of time.

The camera itself installs via a little attachment that clamps to the back of the rearview mirror (which I bought separately) and can be powered by one of two ways. It can be powered by the cigarette outlet on the center console or, for a cleaner install, it can be hardwired to the nearest fuse box using add-a-fuses or similar methods to wire it to an empty fuse slot with constant power (for the parking mode) and accessory power (for normal recording mode when car is being used). I elected to hardwire mine without hesitation because having a loose cord going to the cigarette outlet would have driven me nuts. Before I got the VicoVation Power Plus power management system I had purchased a cheaper power management in the form of a little guy that I wired in-line between the camera and the fuse slot for constant power. The device was designed simply to cut power to the camera if the car battery drops below 11.8V so that if I have the camera’s parking mode enabled in a place where there is a lot of movement, triggering it to record very often, it won’t kill the battery. However, I found out the next time I went to detail my car while having lazily left parking mode on that the cheapo power management device did not work, or perhaps 11.8V was too low for the battery to have enough juice to turn the car over. Some light research suggested that 11.8V would be okay but that’s not definitive. Plus I have an AGM battery and they tend to run higher voltages. So… enter the VicoVation Power Plus. This unit allows for configurable voltage cut-off so I could now cut power to the camera if the battery dips below whatever voltage I want (12.2v is now my go-to). It also has temperature sensors which allow for power cut-off at a configurable temperature which is handy in the Summer. It features some other configurable settings like a timer too. Most importantly though, it has a toggle switch that allows you to switch on constant power or cut if off. This means that instead of screwing around with the tiny buttons on the camera itself to turn parking mode on or off I can just leave it on all the time and flip a switch on the VicoVation device to control whether parking mode is on or off. So if I’m parking in the garage at home or where I trust people I just leave it off, whereas if I am parking at a store or elsewhere I just throw a switch and get on my way.

I strongly prefer mechanical work to electrical work but this installation was straightforward and pretty impossible to get wrong as long as you have some basic electrical know-how. Basically, you mount the camera, tuck the power wire into a space under the headliner along the windshield to the driver’s side A-pillar, remove A-pillar and run the wire down through a gap in the dash down to the driver’s side fuse box in the dash, connect the male cigarette plug to female cigarette plug adapter (included with VicoVation unit), then wire the VicoVation power wires and ground to respective fuse slots (constant and accessory) and a ground source. DO NOT: try to eliminate the bulky cig plug adapter unit and wire the camera directly to the VicoVation line because the camera takes 5V and the power line into the VicoVation is for 12V (hence the cig adapter). I ALMOST made that move because the adapter is chunky and harder to stuff away securely in the fuse box but luckily I had that epiphany before I snipped anything! I don’t think the install necessitates more than that as far as a DIY goes but I’ll post pictures of some of the steps during the install (this is one of the only things I remembered to take pictures of during install!)…


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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #10 (Edited)
Miscellaneous Maintenance & Troubleshooting


***Note: This post does not fit into an exact chronological time-frame as I frankly forget when exactly I did most of the below; these miscellaneous maintenance and troubleshooting items occurred over the course of the last few years




Low Pressure Fuel Pump, Pump Filter, and Control Module

This was a good example of maintenance/replacements I did 100% preventatively, not because I had any actual issues. I don’t have any DIY pictures; I only bring it up as a means to inform people of a few things.

Firstly, the older revisions of LPFP control module for the FSI platforms and early TSI platforms is well-known to inevitably fail. In fact, in case you missed the memo from VW, there is a recall on this part and it can be replaced for free. However, that recall wasn’t issued until a couple years after I did this maintenance. I replaced the LPFP control module with the newer revision which is a bit more robust, internally, and has a heat-sink on it, externally, because the killer of this part is heat. It heats up naturally by virtue of the current running through it but more so because it is trapped under the rear seats where there is no airflow and little space for heat to escape.

I also replaced the LPFP itself as well as the fuel filter. For those readers with B6 Passats, your filter is actually integrated with the LPFP itself. The assembly consists of a separate upper half and lower half that are combined together within the fuel tank. The pump and a majority of the componentry is in the lower half and the filter unit is integrated into the upper half. For Mk5 platforms the upper half contains very little as the filter is NOT integrated into the upper half; rather, the filter is in-line post-fuel pump. Hopefully this picture makes that clearer to see.


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If you’re having fueling issues, fuel related CELs, or similar, and you suspect the issues stem from the low pressure fuel side then the way you can confirm this is by logging data via VCDS or similar. Ideally your low pressure fuel supply should be between 5 – 6.5bar at idle and able to sustain the same pressure range at wide-open throttle and high RPM fuel demands. If the pressure is any lower than 5bar this is suboptimal and fuel supply related issue may occur. If the LPFP duty cycle is over 90% to supply suboptimal or even lower end of the optimal pressure range then you have a slowly failing LPFP, a weakening LPFP control module, or a clogged up fuel filter. The sensor that reports low pressure side fuel pressure is on the HPFP and reads the pressure supplied before it is increased substantially by the HPFP. This means that if your low pressure fuel supply is suboptimal then ANY of the parts I’ve mentioned could be the culprits. Starting with the LPFP control module is generally the best idea as it is the easiest to replace and does not involve opening the gas tank. The fuel filter is usually the next best idea, followed by the pump itself lastly since it is the most expensive part by far.


Axles and Ball Joints

At somewhere around 80k miles my passenger side outer axle boot developed a small tear and started slinging some grease onto my suspension components, wheels, and a bit on my calipers. Axles are pricey and at the time I was between jobs so I wasn’t in the best position to be dropping several hundred bucks on replacements. I came up with an improvised solution in the meantime that you can see below which actually held up so well at containing the grease inside the boot that I was able to hold off for a few months.


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Again, I only bring up the subject because it is an opportunity to discuss axle replacement options. Right out of the gate I must point out that there is more to what makes a good (or even decent) axle than its strength, durability, and reliability. The axle must also be perfectly balanced in order for vibrations not to result during operation; if any particular area of the axle, from one end to the other, is lighter or heavier than OEM it can result in vibrations ranging from hardly noticeable to obnoxious, depending on how unbalanced the weight distribution is. It doesn’t matter if the axle weighs the same, overall, as an OEM axle, that weight has to be the same in all the same places as, obviously, the entire axle rotates.

Cheap axles like the ones you’d get at the local auto parts store typically do not pass muster on those criteria. Mid-tier products like Raxles may. I can’t speak from experience on those particular axles though so I won’t claim one way or the other. All I can say is there is too much disparity in experiences from people I know and in information online for me to have personally been comfortable buying Raxles. They have a good reputation as a company, but for this particular application there was too much disparity. Some of their products for other applications may be better. Top-tier products like those from Drive Shaft Shop are the only ones I would trust to be OEM-grade. Drive Shaft Shop makes very, very high end custom driveshaft components for some seriously impressive race car applications so I would have no problem trusting them to design a simple axle to the OEM weight/balance specification for an 02M/02Q VW transmission. Drive Shaft Shop boasts upgraded, stronger axles for this application. There are several “levels” they offer for varying levels of power. Their “level 2.9” axle is supposed to be rated for “500HP” but I have to take exception to using HP to as the measuring stick for durability because HP, technically, isn’t even real. HP is mathematically derived from torque, relative to a given RPM, and is therefore a theoretical figure. Torque, however, is a real and observable physical force. Torque is twisting force and, as such, any components that are subject to rotation – which is almost every component of the drivetrain and most components of the bottom-end of an engine – are subject to torque. Torque is the real measuring stick of what those components, including axles, can handle. But most aftermarket manufacturers rate their parts by HP anyway, which is unfortunate because it is more generalized and less accurate. In any event, the DSS level 2.9 axles are obviously strong and you’re probably thinking I bought those and recommend them because I went into all this detail but you’d be wrong.

I actually just replaced my axles with another pair of OEM (remanufactured) axles. A remanned axle is just as good as a brand new one. VW will only use axles that are in perfect physical condition and just need rebuilt axle boots for a reman so it’s almost exactly the same as if the parts were greased and booted new from the factory… except you pay less. I was able to get OEM remanned axles for around $850 (including a $350 core charge) and then ship my used ones back for a return of that $350. After shipping I spent about $550 on the pair of axles which is fair. But here’s the main reason why I’d recommend getting OEM axles EVEN IF you have a pretty high-powered build… what a lot of people don’t realize is that the OEM axles are actually very strong! The previous generation of VWs with the previous generation of transmission (the 02J) were pretty notorious for weak axles that could NOT hold up to the torque output of bigger turbo upgrades, even K04 turbos in some cases. That is absolutely not the case for the OEM axles for 02M/02Q transmissions. The OEM axle here is well known to hold up to around 450 ft-lbs of torque for plenty of time as long as they are not being utterly abused with frequent/hard launches. I know a laundry list of guys running more powerful setups then my own current GTX2867R setup on OEM axles. So the OEM axles are basically as strong, or nearly as strong, as the DSS level 2.9 axles. In fact, the OEM axles are so well known for their robustness on higher-power builds that I have to call into question just what separates the DSS level 2.9 axles from the OEM; I have to wonder if they aren’t pretty much the same. To be honest, I’m not 100% sure either way. It may come as a surprise but, for once, I didn’t do a deep dive for info from the manufacturer to figure out what’s special about the DSS level 2.9 product other than that it comes from a company with a good name for custom work. I was content to just save myself $450 over the DSS axles and buy the OEM remanned axles. Moral of the story, unless you have a very high-powered build pushing over 450CTQ (which would mean likely over 500BHP) then you don’t need to seriously consider anything other than OEM axles.


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I also replaced my ball joints at the same time I replaced the axles but there isn’t much to say on those. Went with OEM as well. I considered SuperPro replacements since they allow a small amount of adjustable camber and since I don’t have camber plates I still had no adjustability to camber in the front. However, I’m not looking for much negative camber and the -1 to -1.5 degrees in the front that I have as-is is sufficient for my purposes and preferences. Also, word on the street is that the SuperPro ball joints don’t fit with ST-40 calipers anyway.


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Oil Filter Housing Assembly and Oil Cooler Gaskets

The oil filter housing assembly – specific to the FSI platform – is the multifunctional part that bolts to the engine block and, in turn, has the oil cooler and the oil filter housing itself attached to it. The oil filter housing assembly also has the oil separator integrated into it at the top, where a PCV breather hose runs from the assembly up to the front PCV (on cars with factory PCV), to a PCV adapter plate for cars with standard valve cover and catch can, or straight to the to the catch can on cars without a standard valve cover (like mine).

This is an item most folks have to do at some point if they own their B6 Passat/Mk5 FSI platform long enough. The gaskets fail and/or the oil filter housing assembly itself warps slightly over time from frequent hot-to-cold/expansion and contraction cycles from normal operation. I had only a very small amount of oil seepage from the bottom-right (driver’s side) corner of mine. Due to the cost of an OEM oil filter housing assembly I took a gamble and only replaced the gaskets, not the housing itself, because I was fairly sure the housing was not warped. Thankfully I was correct. My research showed that the aftermarket, much more affordable oil filter housing assemblies are not to be trusted.

There’s not much more to say on this subject because I think just about everything else to be said is covered in the below thread where I did actually write and post a DIY. Myself and some other forums regulars weigh in on the subject their so it is a good source of info.

https://forums.vwvortex.com/showthr...cing-oil-filter-housing-cooler-on-Mk5-GTI-FSI


Hunting the Cause of Oil Burning

If you’re reading this far into my build thread chances are you already know that the FSI, and to a lesser extent the TSI, platform has a serious drinking problem. These cars love to burn up oil. Even absolutely meticulously maintained cars like mine eventually succumb to this issue. The amount of oil burn ranges drastically from barely noticeable to enough that you need to add 1L of oil every 1K miles. In extreme cases I’ve heard of it being even worse than that. VW says that up to 1L per 1K miles is “normal”. In a way they are right, it has become normal. But that’s only because of just how many different sources of the issue there are, at least on the FSI (which I know better). Almost every FSI is bound to develop this issue at some point. So, yeah, it has become normal but it definitely shouldn’t be normal. While I generally try not to presume to know better than VW, in this case I think they are full of it when they say it is normal and they know it is not normal, nor should it be.

Anyway, the silver lining is that aside from burning a hole in your wallet and requiring you to be very diligent about topping off your oil, the issue is fairly innocuous. Most of the causes of this issue do not have any major side-effects (with some exceptions as you will see). Below are THE 5 causes of noticeable oil burn on the FSI motor (I can’t speak authoritatively on the TSI motor).

1) Bad front PCV: failing check valves within the front PCV (it has two) can result in the PCV behaving differently than intended under boost and vacuum which may result in greater quantities of oil being pulled through the PCV system.

2) Bad valve cover internal splash plate/seal: this seal, which is integral to the FSI valve cover, separates the open space of the head from the pass-through channel from the front PCV to the rear PCV breather that routes though the valve cover. If this seal fails oil from the head will be sucked into the PCV tract.

3) Bad turbo oil seal: pretty much self-explanatory

4) Bad intake valve stem guides/seals: oil will be allowed to leak through to areas of the engine it shouldn’t be and burn-up; if this is the cause of your oil burn and IF you have a catch can installed you may find that the contents of your catch can is almost straight oil because the oil will leak down only to be pulled in by the lowest portion of the PCV system that doubles off of the oil filter housing assembly unit with a breather hose routing back up to the valve cover (or straight to the catch can if you have an aftermarket valve cover). In either case the next place the oil goes is into the catch can. Whereas on a factory setup it does not.

5) Bad piston oil control rings (NOT compression rings): let’s be clear, there are different kinds of piston rings. When piston rings lead to oil burning that is an indicator of oil control ring failure first. It does not mean the main piston rings (compression rings) are failing so it does not mean performance loss or noticeable misbehavior of the engine. It also does not mean your engine is going to fail soon. It can lead expedite piston wear but it is not an immediate or even near-term death sentence unless the oil control ring leakage is pretty severe.


Most often oil burn is a result of #1 or #2, if disappearing oil is your only sign. If you had #3 you'd know it and you'd have a lot of blue smoke from the exhaust under heavy throttle. Also your turbo would be on very borrowed time and possibly start developing some unsettling noises due to suboptimal lubrication. You may also notice blue smoke under throttle with #5, depending on the severity. So if you rule out #1 and #2, then #4 is the most likely after those. #4 is quite common too. So, basically, if you have oil burning issues replace the front PCV and replace the valve cover with a new one. If neither works then expect #4.

I’m positive the source of my oil burning is #4. I’ve ruled everything else out. It’s been going on for 2 years now (out of 5 years of ownership) and has worsened slowly. When I first noticed the issue was developing I was only adding about 0.5L between oil changes (every 5K miles). Now I’m adding about 2L every 5K miles. In the case of all of the 5 causes I outlined, the harder you drive the car the worse the oil burning rate will be. There is a very noticeably higher burn rate if you drive at high RPMs and high boost often, due to the nature of the failures/mode of the oil loss.

I have accepted this and just keep my oil topped off religiously. It will get dealt with inherently when I do an R&R on my head and build my motor. I’m basically just waiting for the right time.


Monitoring Gearbox Troubles & Gear Oil Selection Info

A few years back I did the first gear oil change, pretty much just because. I ordered OEM gear oil, drained the old gear oil (looked fine), put the new gear oil in, done. Then two weeks later I happened to realize that the gear oil I ordered wasn’t technically the correct type. It was OEM VW gear oil but somehow it was incorrectly listed for my car on the site I ordered it from. I rushed to get the right gear OEM gear oil to replace the technically incorrect gear oil. I was absolutely appalled at what I saw when I drained the technically incorrect gear oil after only 500 miles of driving… there was a ton of small brass flecks in the oil. I call them “flecks” because they were quite fine, definitely not “shavings” by any means. Confirmed not just by color but by the fact that the flecks were not magnetic (brass is not magnetic).


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I told myself: “alright this definitely doesn’t look good but only so much damage could have occurred to the gear syncros in 500 miles, so I’ll just put this correct OEM gear oil in. Run if for another 500 – 1000miles and then to a hot drain to flush out any remaining brass and I’ll be good to go.”

Wellll… it looked exactly the same the next time I drained out the CORRECT gear oil. There was no less brass, in fact possibly more. I thought I was screwed.

Fast forward 3 years and it is still happening. I’ve drained my gear oil 4 times since then, 2 of which were more CORRECT OEM gear oil and 2 of which were with other brands (more on that later), and with increasingly long intervals between drains, and I still have the same amount of brass in the oil every time. And yet I have absolutely no issues with the transmission shifting, gear engagement, etc. It hasn’t changed one bit, it is flawless.

This is one of the only things I have experienced in my time developing this car that I simply cannot explain to this day. It has gotten to the point where I question whether what I see really is brass even though it so plainly is. I just can’t fathom how that much wear could not result in issues, yet I also can’t fathom what else it could be if it isn’t brass (and the fact that there was none in the first drain of gear oil I ever did, prior to putting in the incorrect gear oil). To make thinks even more convoluted, I later found out after intense research that the “incorrect” gear oil I ran for 500 miles was very nearly the same gear oil as the “correct” oil in all of its properties. So while it was technically not correct, part number for part number, it was hardly any different and it was totally fine that I ran it for a couple weeks. So using that gear oil couldn’t have even been the catalyst for this issue. The whole thing is bizarre and there is too much discrepancy to make a conclusion.

At this point I’ve just let it go completely. Even though it looks like there is clearly a problem, there is clearly NOT a problem because my gearbox hasn’t changed behavior one bit in those 3 years.

I’ll use this section as an opportunity to share my advice on gear oil selection, which comes from both experience and loads of research (as always). First things first, VW specifies 75W-90 gear oil for their 02M/02Q gear boxes which comes across as pretty disingenuous when their own gear oil which is supposedly a 75W-90 is actually nothing even close to that viscosity. In fact, it is about half the viscosity. Just like with my engine oil, I have sampled several of my gear oil drains to send to Blackstone labs for analysis, including both OEM and non-OEM gear oils, and the OEM gear oil ranges about 6-7cst whereas the typical, real 75W-90 gear oil ranges between 12-15cst. You can tell it is thinner just by shaking it around in a bottle compared to a real 75W-90. So one might think that the OEM gear oil is to be avoided since it is so thin but every one of the millions of 02M/02Qs on the road with owners that don’t care to maintain their cars that well and haven’t had their gear oil changed once in well over 100K miles would beg to differ. While I’ll admit that the OEM gear oil is worryingly thin, it is a good gear oil and the proof is in the pudding as they say. While I don’t fully buy into VW’s lifetime factory fill claim for their gear oil and I wouldn’t let it go forever, I do concur that somehow despite its viscosity it is a long-term gear oil and VW knows best of all what to put in their gearboxes.

And with that said there is pretty much no reason to buy an actual 75W-90 from an aftermarket brand. Because about the only reason you would do so is for increased lubricity and wear prevention even under high heat, if you feared that the OEM gear oil would be getting so thin it would be sacrificing wear prevention when it gets hot enough (which causes it to get even thinner). But we’ve pretty much established that is somehow not a concern for the surprisingly thin OEM gear oil. Its effectiveness must just come down to its chemistry (which I have zero qualifications to comment on), since the physical observations like viscosity clearly aren’t as significant as one might think in its case. Want a couple more reasons NOT to buy actual 75W-90? Well, if it gets remotely cold where you live you’ll have terrible, notchy shifts in the Winter until the gear oil heats up and thins out. I found this out first hand when I briefly gave Amsoil MTG 75W-90 a try. Also, technically, thicker gear oil means more resistance for gearbox parts which, technically, means an impact on transmission output; emphasis on technically because this is truly just a technicality and in any practical circumstances, outside of the most extreme race car considerations, this would not matter nor be remotely noticeable.

However, if the thinness of the OEM gear oil just scares you anyway OR if you track your car and expose it to extreme heat and demands that could possibly froth a thin gear oil at high RPMs, resulting in poor lubricity, then you could settle for a middle ground. I’ve been using Redline MTL 75W-80 which Blackstone reports a viscosity of about 10cst for. This is a good middle ground that does not result in notchy shifts ever and will not be incredibly thin when it heats up like the OEM gear oil would. I’ve been satisfied with it for the last 1.5 years.


Turbo Wastegate Preload Issues & Loose Exhaust Manifold

Somewhere around 2 years ago, when I was still on the factory K03 turbo and APR Stage 2+ tune, I ran into an issue that perplexed me for awhile but that I ultimately traced down to an issue with the turbo internal wastegate actuator system and was able to solve by adjusting the preload on the actuator rod/arm. Generally speaking you do not want to mess with the preload for the wastegate actuator but in certain circumstances you may. You just need to be sure they are the right circumstances and that you know what you’re doing. For both of those, it is absolutely critical that you have a very quality data-logger like VCDS because you’ll be relying on it completely to diagnose whether you need to adjust the preload at all and to dial in your adjustments properly.

This will be a rare case where I save my fingers some typing and just provide you with a link to one of my other threads because I have explained this in the utmost detail already on another thread. In this thread I discuss proper data-logging techniques, data interpretation (specifically regarding boost curves and boost control behavior), wastegate actuator principles, and plenty more. Seriously, if you have any interest in learning how to log and interpret logs for boost data then it’s worth a read. The thread starts off with me on the hunt to figure out the nature of the issue (which wound of being two separate issues) because I opened the thread as a diagnosis thread, not a knowledge-base thread, at first. So follow the directions at the TOP of the first post in bold font in the link below, it will give you an overview and direct you to the correct post to skip all the stuff you don’t need to read and get to the good stuff later in the thread.

https://forums.vwvortex.com/showthr...-WOT-only-Seemingly-NO-boost-loss-or-vac-leak!


The second, separate issue which was a bizarre zippy, whistling noise that occurred during brief throttle inputs (such as when rev matching downshifts), turned out to be an exhaust manifold leak. There were literally no other symptoms, no typical symptoms of an exhaust leak, especially not one as large as I found. I wound up, by luck, feeling around and finding out that I had a loose exhaust manifold stud and another one completely missing. Got a new stud and new bolts, tightened everything down and that took care of that issue. Not much more to say there. Nothing to wax eloquent on for this one.


ST-40 Caliper Rebuild

Last year, in prep for track season, I rebuilt my ST-40 calipers that I originally purchased used from Ryan Jacobs, aka HYDE16. They were almost 3 years old when I bought them from him and almost another 3 years old by now so I figured a rebuild was in order, especially since both Ryan and I used them heavily.

When it comes to rebuilding OEM style slider calipers I’ve heard mixed things. Some techs say they don’t advise it because rebuilds have a decent chance of failing. Not necessarily upfront either; just not lasting. I’m frankly not sure how much truth there is to that. Other techs and folks I know have done it plenty of times with no issues. But there can be no disputing that rebuilding a race caliper like the ST-40 is not only completely intended but also quite easy, by design. I should emphasize that it is easy if you have the right tools, whereas it can be a massive PITA and probably go bad if you don’t. This is absolutely one of those jobs that demands the right stuff. For starters you obviously need replacement pressure seals, which go inside the piston bores and seal in the brake fluid, and replacement dust boots, which go in at the top of the bore and keep brake dust and debris from getting inside the bore and damaging the pressure seals/pistons. You typically do NOT need replacement pistons unless you suspect one is damage (typically only possible from overheating from track use or from being scratched if a dust boot completely fails).

Otherwise you’ll just need proper brake parts cleaner and brake parts assembly lube (it is important you use brake parts assembly lube NOT brake fluid or generic lube for the pressure seals and pistons). Finally, you’ll need a race caliper spreader, wood working clamps (more on that in a minute), and compressed air. Those are the more rare items that not everyone has but which make or break the job.

After removing the calipers from the car the first thing you’ll do is use the race caliper spreader (just a caliper spread that can contact and spread all pistons at once because you can’t retract one piston at a time without another sticking out more). You’ll use it to retract all the pistons into their bores at once so that remaining brake fluid inside comes out the hole where the brake line bolts to. This is so that during a later step, involving the compressed air, you don’t have a bunch of brake fluid flying out at terminal velocity. So at this point the calipers should look like this:


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Next you’ll use one of these wood working clamps which you can buy at most hardware stores. Avoid the plastic ones, they may not be strong enough. Opt for the ones with metal frame and slides like this one:


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If you have a 4-piston caliper like my ST-40s then you’ll need 3 of those because at any given time you’ll be clamping down 3 of the 4 pistons while you blow out the 4th with compressed air. Since these clamps will be clamping onto the caliper body you’ll want ones with soft pads on the clamp ends so they don’t mar your finish. Setup will look like this:


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Then you’ll use your compressed air gun with a nozzle on the end to fit it tightly to the hole on the caliper where the brake line bolts to. And, yes, if you hadn’t realized earlier, I wasn’t talking about the compressed air cans, I meant an actual air compressor. The end result will look like this when they are all pushed out far enough that you can pull them out by hand. It is a good idea to put a brake pad or something like that right in front of the piston that is going to be popped out at any given time because it will come out with extreme force. WATCH YOUR FINGERS!


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I don’t have any more pictures for the rest, but that this point you’re basically just going to remove the pressure seals from the bores and then use a fine mechanics pick to pick out any baked on remnants of the pressure seals from the groove they sit in within the bore. If you don’t do this the pressure seals will not seat perfectly flush and the pistons will not install correctly later OR they will tear the new pressure seals while trying to re-install the pistons. Next you thoroughly clean the bores. If they are particularly dirty use brake parts cleaner, if they are not then use a clean, lint-free cloth to clean them out. Then you remove the old dust boots from the pistons, clean the pistons thoroughly, and lube them with brake parts assembly lube (do not get it on the dust boot though). Lastly, you lube the new pressures seals with the same assembly lube, install them nice and flush into their grooves, and then slide the pistons back in all the way. The pistons should slide in with minimal effort from only two fingers. You should NOT have to push hard or use any tools to slide them back in. If you do then you didn’t lubricate the seals correctly or you didn’t clean their grooves out enough so they seals are not as flush as they should. If you persist with trying to ram the pistons down you will damage the pressure seals.

That’s about it. You may be wondering how I can give such specific recommendations… well, I forgot to clean out the pressure seal grooves at first and had exactly the issue I just described so take my advise if you actually find yourself doing this rebuild on a similar caliper. And, again, don’t bother trying to do this without access to an air compressor and the proper tools to keep the other pistons clamped down.
 

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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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1,818 Posts
Discussion Starter #11 (Edited)
A Definite Turning Point


***Note: Late Spring 2018…




Rear Suspension Upgrades

I figure it’s about time to kick-off a post with some picture heavy content instead of a bunch of blabbing. I’ll just highlight what I did with the rear suspension briefly. I gutted the entire rear suspension, including subframe, all at once to install Powerflex race density (90A) rear lower control arm polyurethane bushings and race density (90A) rear trailing arm polyurethane bushings, as well as 034 Motorsport adjustable rear upper control arms w/ 90A polyurethane bushings and 034 Motorsport adjustable rear toe arms w/ 90A polyurethane bushings. Actually that’s not technically true because originally I installed Spulen adjustable rear toe arms w/ pillow-ball spherical bearings instead of the 034 Motorsport adjustable rear toe arms so you will notice the Spulen toe arms in the pics below. I did this only because the 034 Motorsport toe arms were on back-order at the time and I was not being patient. A few months later I replaced the Spulen toe arms with the 034 Motorsport toe arms. I did that for 2 reasons: firstly, bearings are notorious for getting noisy eventually and requiring service – admittedly in can take awhile – but I wanted to get ahead of that and, secondly, I wanted consistency across all parts in terms of stiffness and allowable deflection, which the 034 Motorsport rear toe arms w/ 90A poly bushings accomplished.

While I had everything off I cleaned it all up with solvents and wire-wheeling (where applicable) and painted everything that was stock with gloss black paint (yes I know the paint job turned out pretty **** haha).

I’ll share my impressions afterward; let’s get to the pics…


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As you can probably tell from the pics, some of those bolts were very stubborn and quite corroded. Heat and PB blaster were my friends for this job, but even so I had one of the eccentric bolts for the lower control arms start to shear on me. I had to angle grind the head off the bolt and then punch out the other end. It earned its place on my shelf along with the M14 triple square rear caliper carrier bolt I mentioned in an earlier post.

As for the mods themselves, well there isn’t really all that much to be said. I didn’t buy the 034 Motorsports parts for the adjustability frankly. There’s plenty of alignment adjustability in the rear from the factory so the additional adjustability range is just a bonus. No, the reason I did all these installs was primarily just to stiffen up the rear end and get rid of the slop that exists due to soft, voided factory bushings. These mods certainly accomplished that. The rear in feels much tighter and more composed in cornering, but most importantly it isn’t vague anymore; I can actually feel what it is doing. I don’t think that these mods inherently made the rear end capable of being chucked around corners any faster than before. Rather, they give me the ability to better feel what the rear end is doing and, therefore, have better confidence and ability to chuck the rear end around a corner faster. So they don’t inherently improve cornering speed, they grant the driver the attributes needed to be comfortable and controlled with higher cornering speeds.

You may recall I mentioned this at the very beginning of my thread as the “ace” of the B6 Passat’s sleeve. Its chassis torsional rigidity is rated at 32400 Nm per degree; equivalent to a Porsche 911 (977) and significantly better than the 25000 Nm/degree of the Mk5 GTI. A setup like mine now, where there are no longer parts with give and where the tires I run at the track may as well be glue, is where a car with high chassis torsional rigidity comes particularly in handy. A lot of load goes on the chassis itself now and it can take it, whereas a car setup similarly but without so much torsional rigidity will start to feel twitchy after coming out of a high speed corner when the flex it was subject to essentially rebounds. THAT is where having a stiff chassis is terrific and very, very noticeable. I actually genuinely love how my car takes corners despite ostensibly being a 4-door family sedan.

The rear end is surprisingly quiet in all conditions and situations except when it is cold out. But pretty much all poly bushings squeak when it is cold out. I barely drive the car in the Winter anyway so this is of little concern to me, personally.



Track Alignment

I’ll mention my preferred alignment specs (for alignment geared towards spirited street and track driving) but first I should cover what exactly the alignment specs represent and what they accomplish depending on how they are set (not the basics, I mean the finer details).

1) Toe:
Let’s start with toe. Toe is arguably the most important alignment spec, especially for a FWD car. Strategic toe adjustments have the ability to greatly change the handling of a car for turning into corners, mid-corner steering and throttle input, drag levels on straights, and tire wear. Toe basically gets involved in everything. I’ll primarily focus on the effects of toe on the front/driven wheels, but a majority of the same principles apply for the rear wheels. Toe-in (or positive toe) is when the front point of the tires point inward, towards one another, and toe-out (or negative toe) is the opposite. VW factory specifications call for slightly positive toe. That’s because cars with a bit of positive front toe tend to track straight even with slight steering inputs, so essentially this popular specification choice for street cars is a safety measure for drivers. However, this is counterproductive for performance driving because it means the car is less eager during turn-in and requires more steering input with less feedback through the wheel. On the flip-side, negative toe makes the car more eager and responsive during turn-in and steering inputs. Too much toe out, however, makes the car overly eager to initiate changes of direction and even the slightest input in the steering wheel will do a lot more than you expect it will.

I experienced this first hand right after I performed all the above suspension work because my rear-end had significant toe-out (about -2 degrees) on each side and it was almost dangerous to drive. Granted no-one in their right mind would have that much negative toe, ever, but I'm using the example to illustrate the point. With that much negative toe, the back end wanted to step out of line of the front-end in virtually any scenario other than going in a perfectly straight line, and even then I could feel it wanting to go somewhere else. I can’t imagine how bad it would be with that much front toe-out.

So as you can see, as with most things, toe specifications are a balance. You don’t want too much of either. And to further illustrate that point, I should point out that everything I just told you about toe is completely the opposite once you are in HARD cornering (so we’re talking most likely just on the track now). That’s because under HARD cornering your inside tire is unloaded significantly and its role in the behavior of the car now, from an alignment standpoint, is minimal. Now it’s the alignment spec of your outside tire that matters and if the outside tire has toe-in then it will now be more resistant to understeering through the corner and be more responsive to steering input, whereas when both tires are fully planted it has the opposite characteristics. The reverse is also true for toe-out when the outside tire is the one that is under a majority of the load/contact patch with the road.

And that is why most FWD track car drivers prefer to have their toe zeroed out. While toe can be used to change many characteristics of how the car behaves in cornering and even how it puts the power down under cornering (particularly important for cars that steer and put power down with the same tires), ultimately there are always cons to having one or the other, toe-in or toe-out. Zero toe avoids this and it also ensures one very important thing: zero toe means you won’t have drag on the straight which means you won’t be scrubbing speed potential and that is important for lap times.

2) Camber:
Alright let’s talk camber now. I think most everyone knows what the camber alignment spec represents thanks to the kiddos who run obnoxious amounts of negative camber, not realizing (or perhaps not caring) that too much negative camber is terrible for performance driving. Simply put, camber is when the top of the tire leans inward toward the car (negative camber) or outward away from the car (positive camber). It is highly uncommon to see positive camber. Most cars have a small amount of negative camber, up to -1 degree, from the factory.

Just like toe, the behavior and impact of camber is different when driving straight or lightly cornering compared to hard cornering. It’s only natural and logical since the suspension geometry itself is changing. Camber ultimately controls the amount of contact patch the tire has with the road surface. When driving straight, the tire has the most contact patch when camber is zeroed such that the wheel is completely perpendicular to the street. As soon as you begin cornering, especially cornering hard, that changes because the outside wheels gain positive camber while the inside wheels technically gain some negative camber, but during hard cornering the alignment of the inside wheels is not so important since they are unloaded compared to the outside wheels (same as in the toe explanation). This is why SOME degree of negative camber is desire-able because it will counteract the positive camber gain on the outside wheels when the car is leaning in a corner, with the idea being that during heavy cornering the outside wheels are actually relatively close to zero degrees of camber and thus the tire contact patch is the greatest it can be.

Of course you don’t want significant negative camber because then your contact patch in straights is very poor, which affects not only ability to put power down but also braking performance as the tires contact patch is critical to holding up to heavy braking too. For this reason, FWD track drivers typically have minimal negative camber in the front at -1 to -1.5 degrees max and a bit more in the rear. Rear camber angles range from -2 to -4 degrees absolute max. I tend to now tick in the -2 to -2.5 degree range, but I’ve experimented with more and didn’t like it. That’s because while what I said about the inside wheel alignment not mattering so much during heavy cornering was mostly true, it’s not entirely true. There does come a point where if you have so much negative camber (around or beyond -3 degrees), statically, then when that inside wheel gains even more negative camber from the car leaning into the hard corner, it is basically doing absolutely nothing and then ALL the demands are placed on the outside wheel/tire instead of a majority. That can overburden your rear end grip and you can have counterproductive rear-end handling and decreased grip in ALL scenarios.

Some advanced drivers leverage that tendency on purpose for FWD cars because they actually WANT the rear end to kick out. When the rear end kicks out enough that their front end is now pointed in the direction they want to head out of the corner then they punch the gas and if they have a LSD installed it will tend to pull them out of the corner in that direction. I do not currently have a LSD so I can’t take advantage of this strategy, but that’s coming eventually. Even then I likely won’t run that much negative camber.

3) Caster:
Finally, I’ll cover caster, though there isn’t as much to say here. Caster applies to the suspension behind the drive wheels and essentially is determined by the strut/shocks orientation; whether the top is more forward than the bottom (negative caster) or the top is tilted more rearward than the bottom (positive caster). VWs have quite a bit of positive caster, even compared to most other FWD cars. Mine is even more so due to the type of SuperPro bushings I have in my front lower controls arms (which I covered in post #8). I have about 8.5 degrees of positive caster. Positive caster essentially inhibits positive camber gain mid-corner, so it indirectly translates to better contact patch during cornering. It’s by far and away the least impactful of the 3 alignment specs.


Track Wheels/Tires

I had pretty strict criteria going into the search for a track wheel/tire set so my options were pretty narrowed down from the start. For starters, I was strongly against rolling my fenders to fit an especially wide setup because I am a big fan of the B6 Passat’s body lines as they are and I did not want to stand a chance of ruining them, nor of potentially cracking the beautiful paint. So I had a certain maximum wheel width and offset to work with right from the get-go. Of course I also had maximum wheel weight (of 20lbs. / 9kg) in mind.

Additionally, I had a pretty low budget in mind because, after all, these were going to be primarily track wheels and I tend to prefer spending more money on the rubber than the wheels anyway. So already my criteria were narrowing the options down.

Originally I was looking at 17x9” wheels. Particularly from a weight and dimensions standpoint those would have been ideal. However, there were two problems: firstly, I couldn’t find any 17x9” wheels that met my criteria and looked even halfway decent – and I wasn’t even being that picky about the looks considering these are track wheels – and secondly, the assortment of tire sizes for 17x9” wheels in the categories of tires I was looking at were lackluster. That latter point about tire selections is a massive factor in why I ultimately couldn’t go with 17x9”.

I started looking at 18x9”. There were a few options available that mostly met my criteria but not enough. Some were the right dimensions and weight but simply too expensive to justify. Others were affordable enough but not quite the dimensions and weight I needed.

Ultimately I settled on Motegi MR140 18x8.5 E.T 45mm, weighing in at 19lbs. (8.6kg.) each and costing only $650 for the entire set. These are a decent enough looking wheel and they hit all my criteria perfectly. The ONLY downside to these wheels is that being an 18x8.5” the absolute widest tire I can run is a 255 wide – which is fine since that is most likely what I was going to get on the 18x9” anyway – but on the 18x8.5” the 255 wide is slightly bulgy, instead of squared or slightly stretched which is preferred for performance driving.

No I don’t mean absurdly stretched like the kiddos do. I mean a slight, almost hard to notice, stretch. The reason for this is that a taught contact patch is more efficient at generating friction/heat and thus greater traction on the kind of tires run for track driving and racing than is a less taught contact patch. I deemed the slightly too wide 255 width tires on the 18x8.5” wheels more or less a non-issue though because in the end I still have a pretty large contact patch and the sidewalls of the kind of tires I was looking at are extremely stiff which means that despite these tires having a slight bulge they should hardly have any rollover under cornering, if at all.

On that note, the criteria I was considering for tires made the selection fairly straightforward as well. I wanted the absolute best performance I could get in a tire while still remaining street legal so that if I wanted/needed to use the tires on the street I could. I also had to consider that there are certain classing rules and stipulations for cars running non-street R-comp tires too. So for these reasons I was searching within the “max performance summer” tire category, the stickiest category of street-legal tire. In this category you’ll find legendary tires like the Bridgestone Potenza RE71, still considered the stickiest, best performing street tire of all-time, with good reason. In fact, some speculate that even though the tread compound is given a 200AA A treadwear rating, that the compound is closer to an R-comp. This is plausible as the RE71 wear incredibly fast, even compared to other tires in their category. That is the primary reason I did not go with those legendary tires; not only are they quite expensive, but they wear very fast, sometimes fast enough that you can’t get a full season out of them if you hit the track a handful of times.

I elected to go with the new Hankook Ventus R-S4, the successor to the very popular R-S3. I had never used the R-S4 at time of purchase, but all the research I did suggested that these tires could nearly match the dry performance of the RE71 but wear extremely well compared to any similar category tire. I can now confirm that these tires do not wear like other 200AA A rated tires. That is because when the compound is not hot from heavy use it remains a bit harder, more resistant to wear. Not surprisingly then, for track use these tires need an extra-thorough warm-up lap to get some heat in them. What is surprising though, is that EVEN when they are heated up they still wear incredibly well; these tires are practically immortal to heat. Their outstanding dry traction even in the face of a low-wearing compound is accomplished by a very aggressive tread pattern/design, and therein lays the one concession this tire makes; they are dreadful in wet conditions. Standing water would be dangerous and even a damp surface is not particularly safe with these tires. I was caught in the rain on them once and while I didn’t feel completely unsafe I had to be cautious. But how often does one really intend on running a tire like this in the rain anyway? For me, it’s a non-issue. I’ll take any max performance summer tire that can survive multiple track seasons and street driving and still give it all in dry performance, even if it means poor wet performance.

Anyway, without any further ado, here are some pics of the setup…


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Race Brake Pads & Fluid

I can keep this section pretty short because I’ve said basically everything there is to say on pads and fluid in post #7 under the headings “Notes About Pad Upgrades” and “Notes About Brake Fluid” where I discussed necessary details for considering both street and track applications.

I chose Porterfield R4 pads, the race pad version of the Porterfield R4-S pads I came to love for street use. Porterfield already provided the R4 in the proper pad dimensions for my ST-40 calipers but not in the right dimensions for my factory rear calipers; Porterfield was kind enough to do a made-to-order shipment with a very quick turnaround time.

Both through research, and now personal use, I can say that the Porterfield R4 race pads are a flexible pad in that they cover a lot of key areas and needs well without sacrificing much. Firstly, their optimum operating temperature range is 400F – 1450F (204C – 787C). This maximum temp. range is only marginally lower than some of the most hardcore race pads readily available, and still PLENTY high enough for heavy track use, whilst the minimum temp. range is a few hundred degrees lower than pretty much all other comparable race pads. That few hundred degrees makes a significant difference in how quickly these pads are ready for full stopping power compared to other race pads. These pads get up to temp very quickly. They also boast very consistent bite and performance throughout the entire heat range and at varying levels of braking force, making them predictable and easy to modulate. This comes at the expense of only one thing that SOME track drivers like; these pads don’t have a particularly hard initial bite. I personally prefer the consistent bite though because it means I can better predict when I need to get on and off the brakes than if my pads give a false sense of stopping distance by biting really hard initially and tapering off, but it comes down to personal preference.

The typical routine for a track day involves swapping the R4 pads in BEFORE I leave for the track so that the R4 pads, which on the street rarely get up to temp, will be operating in full abrasive mode (as described in post #7) and will clean the pad material deposits from my street pads off of the rotors prior to getting to the track. This is important for consistent performance of the R4 pads. All the tracks I go to are within 70 miles of either my place or a friends place in CT which isn’t enough to cause any significantly increased wear to the rotors, despite the fact that when the R4 pads are NOT up to temp. on the street they are harder than the rotors. If I had to travel much further than that I would swap the pads at the track and have to use a practice lap to polish the rotors with the R4 pads. After the track day I basically do the same in reverse; I drive back to my place or my buddies with the R4 pads on to polish off their own pad material deposits so the rotors are clean and ready to accept a new bed-in of pad material from the street pads after I swap them back on. I swap the track wheels/tires on at the track though typically, although considering how well the Ventus R-S4 tires wear this is really not necessary (a few hundred miles on the street is nothing to those tires).

As for fluid, I use Castrol SRF. As said in my post #7, Castrol SRF is king of track fluids for folks who don’t want to flush their fluid every or every other track event. That’s because it has an outstandingly high wet boiling point. Its dry boiling point is nothing to sneeze at either, although some higher tier Motul race fluids have higher dry boiling points. But if you don’t want to flush your fluid multiple times throughout the Summer the Castrol SRF is the way to go. It is very pricey, but if you buy from FCP Euro you can literally return the used brake fluid and get the same fluid new for free. They literally let you warranty used brake fluid and get replacements, so you can essentially buy Castrol SRF once and have a lifetime supply. They are based out of CT so while I was up there for track season I stopped by and they explained that this business model pretty much only works because it keeps customer loyalty and the word of mouth helps too… so spread the word! Really cool guys by the way.


Track Density Motor/Trans Mounts

I’ll cut right to the chase… there are good reasons that I chose to call this section “A Definite Turning Point” and while the rear suspension upgrades were one, the major one is these mounts; when I replaced my 034 Motorsport street density motor/trans mounts with track density mounts (Torque Solutions 75A poly mounts) I basically ruined the nice, balanced refinement I had with my Passat between a pretty pleasant street car and a pretty capable track car. These mounts crossed the line. While I have gotten used to these mounts myself, there is no denying that this car is no longer pleasant on the street for anybody but a gearhead.

In larger gears (e.g. the lower gears) like 1st and 2nd gear I can hear literally everything the trans is doing at low to medium speeds and throttle input. I mean I can hear the gears and input shaft spinning and I can hear the gear syncros interfacing with the gears when I downshift to 1st gear and begin decelerating afterward. Only if I give medium to heavy throttle input in those gears would the engine and exhaust sound drown out what I hear from the trans. Mind you that’s all assuming the windows are up and there’s no music on; although I prefer to listen to the music of the car itself over actual music, I do have the windows down most of the time and it’s not bad with windows down.

When I first installed these mounts it literally changed how I get going in 1st gear. It changed the way in which I had to use the clutch to get started such that the window of engagement is even narrower then it was before on this fairly heavy clutch. The race density trans mount removed every bit of slop that was left.

Thankfully the vibrations aren’t obnoxious in smaller, higher gears. Everything smoothes out pretty well up there so at least highway cruising isn’t bad. And of course this car never felt so locked down and solid as it did after I put these mounts in. It’s basically what I described in my post about the 034 Motorsport street density mounts but x5 (the good and the bad). The final pro is that, just as with the 034 Motorsport mounts, engine noise under heavy throttle is amplified and sounds even more “angry”. The engine actually sounds pretty damn nasty (in a good way) now for a tiny 4 cylinder. The sound makes you think: “there’s definitely some pent up power in that thing”.

You’re probably wondering, why I installed these in the first place or why on Earth I kept them in. Well, here’s why…


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That’s actually not my 034 Motorsport engine mount, it’s my good buddies. His failed first because he put more track days on it than I had at the time. But seeing how loose his engine was after that crack and how bad that could have been if it had gotten any worse, I decided to get out ahead of the problem and upgrade mine before anything bad happened. When I pulled mine out they were pretty much fine, but I realize I had to make this change to the race density mounts if I intended to track my car consistently. So the answer to your hypothetical question of why I chose to do this to my car, why I chose to effectively ruin what was a nicely refined car, is that I really had no choice. I wasn’t about to let this stand in the way of doing what I enjoy most with the car, what I spent all this money up to this point to be able to do with it.

It’s still perfectly street-able and it’s not really that bad once you get moving and out of the lower RPMs/gears. I got used to it all pretty quickly, although I have to give a heads-up to new passengers so they don’t think the engine is about to blow up when I start out from a stop HAHA. That’s fine, I don’t have many passengers in this vehicle anyway. These mounts were basically a small concession I had to make for the larger objective of my car. And, yes, that objective changed significantly over the years.

The last hypothetical question might be: “well why did I choose torque solutions?” Well, frankly, because they were by far the most affordable and because for the most part mounts are mounts. If you’ve read this far into my thread you know by now I’ll spend a pretty penny if there is an appreciable significance to the design that justifies its cost, but when it comes to motor and trans mounts that really isn’t the case. It’s a thing that mounts to the chassis on one end and the motor or trans on the other, with a medium in-between, typically made of either rubber or polyurethane. There may be some slight design variations from mount to mount that impact their ability to articulate a bit irrespective of the rubber/poly bushings (I’m thinking mainly of the redesigned version of 034 Motorsport’s track mounts), but when it is all said and done the vibrations are going to be obnoxious no matter what. It just comes with the territory. I’ve been in other VWs sporting almost every other kind of track mounts on the market, and some that were made custom, and they all have pretty much the same results. So I chose Torque Solutions since they are the simplest (yet effective) and most affordable design.

Here are some shots of installation, for some reason I forgot to get an after-picture of the trans mount though, oops…


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Custom Machined Dogbone Pendulum bar

As early as the time I was looking at upgrading to the VWR subframe dogbone mounts (covered in post #8) I was also interested in upgrading the dogbone pendulum bar itself but I couldn’t. The reason for this is that, despite how all the dogbone pendulums out there are marketed, there is no offering on the market that properly fits the B6 Passat. I owe it to Charles from NGP Racing of Aberdeen, MD for pointing this out to me back then. Charles is a very knowledgeable and stand-up guy and it’s thanks to him that I became aware that the B6 Passat shares its dogbone pendulum with the Mk2 TT, NOT the Mk5/6 Jetta/GTI. The B6 Passat’s dogbone pendulum is slightly longer and this means the bolt holes don’t line up unless the engine/trans were to be pulled into line to force the fitment. I don’t think this would even be possible with my extremely stiff engine/trans mounts with 75A durometer poly bushings that have very little flex. However, on a car with factory or lightly upgraded engine/trans mounts (e.g. 034 street density rubber mounts) it would be possible. It would be a bad idea, though, because it would put extra static load on the mounts, increasing noise, vibrations, and harshness (NVH) even more AND decreasing their lifespan.

I decided to do it right. It took me awhile to make that happen though. I had to come up with the design specs and I had to find someone with the right equipment/machinery to make it happen. I procured a Torque Solution dogbone pendulum bar for the Mk5/Mk6 platform to use as the design inspiration. My thoughts on the Torque Solution dogbone pendulum bar are the same as on their engine/trans mounts that I have on my car: they have a simple but effective design. For the most part, mounts are mounts. They’re a thing that anchors one thing to another thing and, in my opinion, simplicity is best when it comes to mounts with the single purpose of track performance. The Torque Solution dogbone pendulum bar is the closest one on the market to mimicking the design of the factory mount too. It is basically just a stiffer version of the factory unit. Again, simple but effective. The more complicated, the more things can go wrong and the more they need servicing so I’ve avoided that.

So once I found the right guy for the job we got to fabricating my very own custom piece, based closely on the Torque Solution pendulum bar, but with the proper measurements to bolt right up to the B6 Passat without needing to move the transmission whatsoever. The pendulum bar is CNC machined out of Kaiser 6061-T6511 billet aluminum with a polyurethane bushing that is 75A durometer (track density). It is not anodized or painted as this would have added extra overhead that I wasn’t interested in. Aluminum is resistant enough to corrosion and I don’t even take my car out in remotely wet conditions these days so the raw aluminum mount should be fine.

What were the results? It actually made fairly little difference and I suspected as much. That’s because with the Torque Solution engine/trans mounts there was already so little movement that the factory pendulum bar was barely an inconvenience. By the same token it did not magnify NVH to any noticeable extent. So basically it had no downsides (besides cost and effort, but what are those? Haha) and the upsides are just slightly less movement in the engine/trans when accelerating and shifting, as well as a very durable bushing instead of the weak factory one that could have conceivably ripped from track abuse. I’d count it as a success even if it didn’t carry any substantial benefits in itself and, at the end of the day, I had to upgrade it to know if I was missing out or not.


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Registered
2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
Joined
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1,818 Posts
Discussion Starter #12 (Edited)
More Powaaa


***Note: Summer 2018…


At long last, a full year and a half after the fact, I’m diving into my write-up on the "big turbo" project. I imagine that, for those of you waiting, the time it has taken for me to get to this post, as well as the many premature “it’s coming soon” teasers, has all probably gotten wearisome. Hopefully I haven’t lost too much original interest and hopefully this will still be viewed by a good number of people to spread the info that I will be packing it with; knowledge sharing is primarily what this thread is about after all. As usual, I will endeavor to put out as much useful information as possible within the character limits of a forum post (actually 2 because it just wasn't possible to fit all that I wanted to into 1 post without making massive concessions).

What follows is some mid-install and post-install pics and info about the factors that went into my decisions on parts selection, as well as my retrospection on the choices I made and performance of the parts so far since I am writing this well afterward. Let’s kick it off with the big one…


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Fundamentals For Turbo Selection

There are loads of turbo options on the market and choosing from among them involves consideration of many factors. Some factors are influenced by personal preference/goals and are somewhat subjective, whereas others are pretty much concrete/factual. The way I would describe it is that out of the total number of options on the market, the concrete factors – the ones that determine objectively better or worse options – help to slim the list down to a much smaller and more manageable number of options. Then, with that slimmed down list of turbos that would all be pretty fine, one should start taking into account their personal preferences in turbo behavior, characteristics, so on, and their goals like current/future power goals, budget, etc.

Two of the biggest weed-outs for turbo options that I would characterize as concrete/factual weed-outs, come down to quality and size. There are certainly more than that but most of them probably fall under those two umbrellas anyway. Those are the two I am going to discuss.

1) Quality:
I don’t have all that much to say on the “quality” subject because while I am pretty knowledgeable, at the end of the day, I am not an engineer (not that kind of engineer anyway) and I don’t have insider industry information either. Anyone with the same inclination as I have for voracious researching, cross-analyzing information, and going to check out/try out different setups in-person, could learn what I have so I’m not going to claim to be an authority on the subject nor make claims about quality that would require me to be an authority. All I will offer is an emphatic reminder of some prevailing knowledge/wisdom that you can pretty much take to the bank; that is, when it comes to turbos the age old adage “you get what you pay for” really does apply. It is in one’s best interest to give greater consideration to OEM brands like Garrett and Borg Warner, or high-end aftermarket brands like Precision and TTE. Though you’ll find plenty of people backing “Frankenturbo” and borderline no-name turbo brands prevalent on eBay, those are experiential anecdotes and, in my opinion, count for less than the simple fact that those kind of options use cheaper materials and have less R&D (which all comes back to the above adage). Whether that actually winds up mattering and biting any given buyer in the arse later is something no one can predict. It’s simply something that should be considered along with all the other factors that go into choosing a turbo.

2) Size:
The most fundamental principle behind making a good turbo selection is choosing one that is well matched to the displacement of the motor it will be paired with. A lot of people talk about turbo size almost as if it is a self-contained subject but choosing the size of a turbo is entirely relative to the size of the motor and should ALWAYS be considered in that light. Recall Jeremy Clarkson’s famous words: “exhaust gasses go into the turbocharger and spin it, witchcraft happens, and you go faster.” Surprisingly accurate for a joke. I’ll just add clarity about some of the internal parts. There is a turbine on the turbo “hot side” which is spun by the exhaust gases and a compressor wheel on the turbo “cold side” which is attached to that turbine via a rod and spins along with it to compress air and stuff more air into the engine per unit of time. The turbine and compressor wheel can only spin so fast (relative to their own size and the volume of exhaust gases acting on the turbine). So a turbo’s air flow potential (and thus power potential) is capped at how much air it can feed to the engine when the compressor is spinning as fast as it physically can. The reason that is all relative to the engine size is because a given engine of a given displacement (e.g. 2.0L) needs a given amount of air to mix with a given amount of fuel at a given RPM. So many “given” factors at play there, and some of it ultimately comes down to other hardware and software tuning parameters, but the turbo has to have the potential and the underlying point is that the ideal turbo is capable of flowing enough air at its limit to sufficiently feed the engine at its own RPM limit.


Understanding/Assessing The Ideal Turbo

Think of the turbo’s air compressor like a typical house fan because it is fundamentally the same thing and, not coincidentally, their flow potential is measured in the same way (cubic feet per minute, or CFM). If you were to set up a well-controlled experiment with a smaller house fan and a larger house fan (within reason of each other) and you were to measure the air flow they produce within a short period of time after plugging them in to a wall outlet, the smaller fan should produce more flow as it requires less energy to spin up and reach its faster peak speed. If you increase the period of time at which you take the air flow measurement, however, the small fan will lose because even at its peak speed the limit of flow potential is lower due to its smaller size and ultimately the larger fan that spins slower will out flow the smaller fan; the larger fan just requires more energy to get going. This is basically a point-for-point analogy of how a turbo operates, wherein the energy is literally conferred by the exhaust gases instead of a wall outlet.

The ideal turbo is just large enough to comfortably provide enough air flow potential, within its own efficiency range, to satisfy the engine’s air intake needs at its maximum RPM and thus continue building consistent power all the way to redline; the turbo should NOT be so large that it is overkill for that purpose, at the expense of “spool” time (time it takes to spin up and start making good power in the lower RPMs). This is how to choose a turbo that makes full use of the widest range of engine RPMs possible, otherwise referred to as the “powerband”, which will make the cars power deliver well-balanced in all situations (barring all extraneous, non-turbo related factors like traction, other hardware, software, etc.).

Secondary factors that play a role as well are things like the material of the turbine and compressor wheels (lighter is better) and engine exhaust manifold design (e.g. tubular manifolds which improve exhaust gas characteristics like temp and flow to improve turbo delivery characteristics), and while these are important, I am not going to dive into those particulars. I think with the above fundamentals covered, any reader can figure how those other factors come into play.

One of the best ways to determine if a turbo meets criteria, based on the above understandings, is to look at the turbos compressor maps. Most companies release this information and it can be found on the web. Also pay close attention to the engine displacement that the manufacturer notes the turbo is most appropriate for. Recall earlier I mentioned that AFTER taking into account concrete decision factors like all of the above, that you should then start to weigh in your own personal goals like power goals, etc. If you’re following closely along to my explanations so far, you may realize that your personal power goals are going to have to bend to the above concrete goals of achieving perfect turbo efficiency balance for your engine size. You can’t have it all. You simply can’t have a turbo that makes massive amounts of power at lower RPMs and higher RPMs. It is all a balancing act. Some people choose to chase after peak power figures so they choose larger turbos that flow tons of air at the highest RPMs possible but at the expense of power everywhere else in the RPMs range. These cars are pretty much only fun on the highway or drag strip. Other people, like myself, prefer to choose a turbo that is perfectly sized to achieve pretty good low RPM power, phenomenal mid-to-high RPM power, and consistent power approaching redline. This is functional in any driving situation. Literally all of this assumes you’re focused on a single turbo setup; it all goes out the window if you’re considering trying to fit a twin-scroll turbo setup with 1 smaller turbo and 1 larger turbo working in tandem (these are exceedingly uncommon on VW platforms due to space constraints).


The Turbo I Chose

I was able to find the most solid information (including compressor maps, performance characteristics by engine platform, etc.) on several Garrett GTX series turbos I had my eye on. I originally had my eye on some similar-sized EFR series turbos from Borg Warner but was not able to find as much data. Of course, I also considered the tried and true BW K04 as well as modified K04 “hybrids” from companies like HPA, TTE, etc. Ultimately I ruled out K04 and K04 hybrid options quickly. That is because my goal was to achieve the limits of my stock engine (which are quite a bit higher than most people think – more on that later), while also leaving ample room for greater power in the future if I upgrade the engine with stronger internals. I also wanted to achieve this on 93 octane pump gas (NO increased fueling like higher mixtures of ethanol or auxiliary fueling like water-methanol injection). So, in other words, the turbo would be bearing the brunt of the demands to create greater power through greater air flow, rather than through the increased engine timing advance that is possible with the aforementioned additional fueling “upgrades”. That said, contrary to popular belief, a standard K04 is NOT able to maximize the power potential of even the FSI 2.0T on stock engine internals, with 93 octane pump gas. It could with E85 or WMI (as mentioned above) but not on pump gas. Even with E85 or WMI, to reach the power potential of the stock FSI engine the K04 would need to be pushed beyond the limit of its efficiency range. Recall that earlier I emphasized the “efficiency range” because although a turbo can be pushed hard to provide just enough flow for peak RPM, pushing it this hard will cause it to get very hot which shortens its lifespan and increases the air temps going into the engine. Increased air intake temps (IATs) lead to higher combustion temps, which can cause pre-detonation/knock in extreme cases, but in all cases will still cause the engine to run hotter, produce higher exhaust gas temps (EGTs) and heat up the turbo and everything else more and more, cyclically. This is not ideal for a long-living turbo or engine, especially if they will be beaten on daily or for extended periods at a track. The story is pretty much the same (albeit to a slightly lesser extent) for the K04 hybrid turbos which have a little bit more flow potential at their peak but still would be pushed near their efficiency range limits to meet the goals I had.

Since it was down to the GTX or EFR series turbos and I had much more data on the GTX series, as well as the fact that they were a little more affordable, I chose to go that route. I had my eye on the 2nd generation GTX 28-series. The 2nd generation have light turbine/compressor configurations, great compressor map data, and impressive peak output potential for a 2.0L engine. They are well reputed to be reliable and the 28-series has an assortment of sizes that are all reasonably suited to a 2.0L engine. The only matter, then, was to decide on which of those. I settled on the Gen 2 GTX2867R which is one of the larger of the 28-series but not the largest. The smaller Gen 2 GTX-series turbos would not be pretty comparable to a K04 hybrid; where, as the largest of the Gen 2 GTX-28 series would have been slight overkill for my intentions. I wanted to retain quick spool and be able to build and hold power right up to redline. Based on my research, data suggest the Gen 2 GTX2867R would do just that perfectly, as the data showed that it reaches full spool on a 2.0T only a couple hundred RPM later than a K04 but builds power much more easily to a higher RPM.

With the turbo choice made, I then had only to decide whether I was going to buy the additional necessary parts (e.g exhaust manifold, wastegate, coolant lines, oil lines, etc.) to install the turbo with a piece-meal approach or buy them as part of a kit. At the time I was mostly focused on choosing the best possible turbo itself but otherwise getting run-of-the-mill, decent quality installation parts that would get the job done. I wasn’t entertaining fancy exhaust manifolds, special oil/coolant lines, exhaust manifold and downpipe thermal coatings, or external turbo wastegates, etc. Had I known I would later be faced with somewhat too-high temps at the track, fitment issues with my turbo heat blanket due to the kits hardware, and immediate reliability issues with the standard internal wastegate design, I might have considered a more thorough setup. I’ll detail all of those issues later in the post. Ultimately, since I didn’t see those issues coming, I chose a run-of-the-mill ATP stock-location turbo kit.

To be clear, the ATP kit was/is fine. The quality is good enough and ATP customer service is excellent. The things I mentioned above that I will dive into later, even the wastegate issues, are not ATP’s fault. The ATP kit came with the turbo and all the major parts requirements but is NOT a bolt-on kit like you would get from APR and similar. As you will see below, some creativity was necessary. It is also a hardware-only kit; it does not include software like APR and some other companies do. I was very close to buying the APR stage 3 kit that uses the Gen 2 GTX2867R but chose to go the ATP kit route with custom tuning by United Motorsport to save money. I can tell you definitively now that after fabrication costs for some additional custom parts I needed (which I would not have needed for the APR route) and after separate costs for tuning, I did NOT save much money and the net result (for now) is not as good as what it would have been if I had gone with APR. Had I gone with APR all the hardware that supports the turbo installation would have been better (e.g. an inconel exhaust manifold which is highly heat-resistant and corrosion resistant compared to the standard cast iron ATP manifold). Since the APR kit is plug-and-play I also would not have had to relocate so many parts, which took up more of my time, nor would it have required custom fabrication, which costed more.

The ONLY silver lining is that my setup is more unique and also since I am using UM for custom tuning there is room to exceed what APR tuning offers if I build my engine to handle more power in the future. That is, of course, because custom tuning will allow me to push greater limits than APR’s “off-the-shelf” tune. That is just about the ONLY circumstance in which custom tuning winds up being better (see my post #4 regarding misconceptions on “custom” tuning vs. “off-the-shelf” tuning). I’ll expand later on a lot of the hardware subjects I brought up above, for now enjoy the pics…


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Custom Work For Turbo Installation

There was some custom work needed to accommodate the turbo installation due to limitations of the kit I went with. I had turbo inlet and outlet pipes fabricated. The outlet pipe is a pretty standard charge pipe but the inlet pipe needed to be a little more intricate because the diverter valve and N75 units needed to be relocated and I elected to have the inlet pipe serve as a junction for both the obvious air intake function as well as a pressure dump location for the DV and N75. In addition, the inlet junction pipe accommodates the outlet from my catch can and the EVAP cross-over tube that would traditionally hook into the valve cover if weren’t for my IE valve cover. Basically, the inlet junction pipe accommodates everything that the factory K03 turbo housing used to accommodate in various locations but that the new turbo does not have any provision to accommodate.

I also needed somewhere to locate the physical N75 unit itself so there’s a small bracket that it bolts to along with my catch can, which puts the N75 in a nice, service-able position should I need to replace it. I like how all these custom-fabbed items turned out. They add a unique touch and the shop who did the fab work did great work. Below you can see the inlet junction pipe before it was wrinkle-painted black and you can see the DV relocation adapter provided by ATP, as well as the results after installation.


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Wastegate Actuator Info & How to Avoid My Troubles

Not everything turned out perfectly with the turbo kit I chose. Under hood temps, turbo temps, and thus oil/coolant temps (since they run through the hotter turbo) are higher than I’d like and that is due to the very run-of-the-mill exhaust manifold and the fact that my turbo blanket wouldn’t fit due to the massive turbo-to-downpipe adapter plate that comes with the ATP kit. Since I wasn’t anticipating that I never shipped the exhaust manifold or downpipe out to be thermal coated by Swaintech (a company renowned for their very effective and durable coatings).

But those are more irritations after-the-fact (and mostly because I track the car) as opposed to the straight-up problems I had with the wastegate actuator unit I initially got with the kit, so I’ll go into some depth on wastegate actuators, their function, and when to use which kind.

Let’s start with the basics. All turbochargers have this thing called a wastegate and there are essentially 2 kinds; internal wastegates (IWGs) and external wastegates (EWGs). Factory turbos have IWGs and I’m going to start with how they operate.

1) IWG function:
The IWG is simply a little hatch door inside the turbo that opens outward into the exhaust gas stream. The WG door is connected to an actuator via a rod. The wastegate actuator (WGA) has a diaphram and spring setup inside that is designed to open at a certain level of boost based on the spring rate of that spring (and also based on the tension on the rod - which is adjustable but not always externally adjustable). Those are the physical components for boost control but there needs to be a controller: enter the N75 boost control solenoid.

2) N75 solenoid function:
The N75 has a total of 3 vacuum lines connected to it. One goes to the WGA, another goes to a dump (into the intake stream or turbo hot side somewhere) to do nothing, and the last picks up the boost from a boost source. The ECU commands a "duty cycle" of the N75 which reflects how open the N75 solenoid is. If the N75 duty cycle is maxed (usually represented by 99.6% if you’re logging that data) then it is fully open and ALL boost running through the N75 from the boost line is getting dumped to the intake stream though the other line. That means that NONE of it is going to the WGA so the WGA has FULL force on the WG door itself which will stay fully closed, thus the turbo will build full boost because it is not releasing any of the exhaust gases it needs to spin the turbine and compressor. If the ECU commands a completely relaxed N75 duty cycle (0%) then ALL the boost (that the N75 will ALLOW) is going to the WGA which means the WG itself is wide open. I emphasize what the N75 will "allow" because that is actually a MAX of approx. 50% of total boost and we’ll touch on that later). If the N75 duty is fluxuating the WG will be flipping through the range of either mostly closed or mostly open and anywhere in between in order to VERY rapidly adjust boost levels built by the turbo. The ECU commands all this based on the actual boost (seen with the MAP sensor) vs. the specified boost (modified by tuning software) and makes predictions of how to keep actual as close to specified as possible via the boost control functionality described above.

3) EWG function:
For EWGs, all of that behavior described above is fundamentally the same. However, as you may have guessed, the EWG is not incorporated into/onto the turbo itself; rather, it is remote and has the necessary boost/vacuum lines going to it in order for it to behave and be controlled similarly to the IWG. The advantage, however, is that since it is remote it can be more easily serviced/modified. You can swap out different WGA springs with different spring rates to compensate for higher boost or lower boost tuning, as needed for the given build plans, rather than buying and installing a whole new unit like you would need to for an IWG actuator. So not only can you control the EWGs themselves to be more precise but they also tend to be more robust and reliable as well.

The only drawbacks are that EWGs tend to be a bit more expensive and must be setup/calibrated/tested to use just the right spring. Some say that EWG setups do not cooperate with the N75 boost control as well but that is a false premise. The EWG operates in the same fundamental way as the internal wastegate and can be used perfectly well in tandem with the N75 factory boost control/ECU tuning; it is only in extreme and specialized builds where the N75 boost control itself may not be accurate enough or in cases where the tuner otherwise has a boost controller they prefer more where the N75 may be replaced and that is not the EWGs fault, that is simply representative of the level the build is at or the preferences of the tuner. Switching to other electronic boost controllers or especially manual boost controllers is bridge that should only be crossed if it is absolutely necessary because it involves dialing in settings that are totally divorced from the ECU itself. The boost control parameters will behave as a separate entity and exist and are adjusted separate from all the other data the ECU processes and controls. The factory ECU and boost control system should pretty much always be trusted and leveraged together if at all possible and only replaced if it is genuinely insufficient which would be a rare build. There are much more powerful/specialized cars than mine using the N75 factory boost control perfectly well.

4) IWG vs. EWG:
The WG decision depends largely on how much boost you plan to run. IWGs have a sort of sweet spot in which they are most effective. Contrary to popular belief, they aren't particularly good for lower boost applications because in lower boost applications a significant amount of exhaust gases are being bypassed away from the turbo out the WG to keep boost down and that means more volume of exhaust gas needs to make it out that relatively small IWG door. If too much needs to be bypassed for that little IWG door then you get back-pressure. On the flip side, IWGs tend not to be used on very high boost applications because it’s hard to design ones that can hold up to very high boost with those small internal actuators and springs.

That said, you can usually get IWG actuators that are up for all the boost that your typical or even pretty extreme VW BT build is going to throw at them. Recall that earlier I mentioned that the MAX boost the N75 solenoid will allow to reach the actuator is approx 50% of total boost created by the turbo. Good, then it should make sense that the rule of thumb, IF you have the factory N75 boost control system, is that the IWG door can stay closed against approx. 2X what the actuator is rated for. So you could theoretically hold up to 3 bar turbo boost (44PSI) on a 1.5bar (22PSI) IWG actuator. Be careful who you get an IWG from. My original 1bar IWG (14PSI) that came with my kit seemingly was not QC checked very well. I believe that was Garrett’s fault not ATPs. I would still recommend Garrett turbos, I would just recommend testing the IWG actuators before installing so you can adjust the rod tension while off the car (that goes for IWGs from ANY vendor because they just aren’t super accurate devices). Anyway, my original actuator should have been good for 14PSI and thus I should have been able to make up to 28PSI but I could only make 24PSI (barely) because the wastegate was struggling to stay closed. The actuator I got wound up only being able to hold up to about 12PSI instead of 14PSI. I later found out that is "within acceptable range" for some vendors! So it seems that at least in some sectors of the industry IWG ratings are not very well controlled from the factory. If you bought a kit from, say APR, though they would probably check it and calibrate it if needed BEFORE selling to you.

As far as EWGs... well there isn't really much else to say. They do what they are meant to do as long as you choose the right spring rate and are willing to put in the time to get everything right. You have the control.




The New Tuning

I mentioned that I nearly went with APR’s stage 3 GTX2867R kit which would have included tuning software. While I am upset I missed out on the quality of the kit, I’m generally happy I went the route that I did with custom tuning by United Motorsport because, while my current UM tune has little or no advantage, after my build evolves in time there will be room to evolve the tuning with it and then the advantages will be realized. That is the only reason I went the custom tuning route, because for a big turbo build that you anticipate evolving with non-standard hardware setups that no shelf tunes accommodate then you will have that versatility with custom tuning. Otherwise I advise against custom tuning (read post #4 on the subject).

There are loads of custom tuners out there using lots of different software and different tuning strategies, preferences, etc. As a software engineer, avid VW enthusiast, general tech enthusiast, and dabbler with some of the tuning software out there, I’ve become pretty familiar with how tuning works and I briefly entertained the idea of doing it myself. Eventually I decided that I just didn’t have the time to get it just right nor did I want to risk burning lots of money if I screwed up and learned something the hard way. I had a pretty high degree of confidence that wouldn’t happen but that’s impossible to predict. I decided it was better to go with a professional and one that does not rely on mainstream software that is somewhat watered-down in order to be approachable by the average end-user (e.g. Eurodyne and, to a lesser extent, Cobb Accessport). Post #4 goes into more depth on what I mean by that last statement. I wanted a tuner that has an actual software developer on staff, has their own software to perform tuning, and has a history of success getting the most out of the 2.0T VW platforms while remaining safe.

To that end, I wound up deciding on United Motorsport. They’ve basically lived up to those expectations. From the get-go they had to write large parts of my tune from scratch, instead of using an existing template as a base, because of the B6 Passat electronic parking brake module. They were sparse on the details as to why (which did bug me and we’ll come back to that theme later) but they did NOT charge extra for all the extra work that this required so I’ll give them kudos for that. If I had to guess the problem was likely that, since they had never written a tune for a B6 Passat before, their templates did not include that data at all and could not be imported to replace mine. So, rather, they probably had to export the data from my ECU, including that EPB module data, and write a tune mirroring their preferred starter template tune within that matching dataset and then import THAT back into my ECU so that the EPB module data would not be missing or corrupted.

I’ve had a few revisions of tuning from them so far. There was the first tune which was done with the bad wastegate actuator and was functional and safe but far missed the mark of my power goals. Then there were a couple more revisions done after I replaced that with a free overnight shipped 22PSI base-pressure IWG, courtesy of ATP for the first failure. The latest of those tunes is the one I’m currently on and making my power and drive-ability goals with. They’ve produced pretty great tunes that are on the aggressive side but have been safe for almost a year and a half of hard, hard abuse on my stock-internals motor. These tunes have had no drive-ability issues, they always feel smooth and start-up, idle, part-throttle, full-throttle, etc. all behave well.

My only complaint is that UM doesn’t seem very interested in taking customer input/opinions seriously during the tuning process. In their defense that’s probably because a lot of their customer don’t know enough but there are surely those that do and they should be heard. So far, I can’t argue with UM’s results and I do not regret going this route, they do good work and definitely know what they’re doing. I just think that if specific circumstances should arise in the future as my build evolves to where I want one thing and they want to do it another way we might butt heads. Hopefully not though.




Hitting The Dyno With a Weak Wastegate Actuator

When I was finally ready to go for a good hard drive, while data-logging to assess the tune, I could clearly see that I was not able to reach specified boost. I was peaking 3-4PSI less than I should have been even with a maxed out N75 duty cycle which indicated that the IWG was opening prematurely and allowing too much exhaust gas to escape at WOT (I knew this since I had already ruled out boost leaks). This was definitely taking a hit on my power figures, my powerband, and my spooling time, which I could prove with logs and some calculations. There are actually formulas using mass airflow, fueling, and timing data that can calculate power output. The mass airflow data alone can be used for simple calculation but the fueling and timing data can be added to try to improve accuracy. I expected these figures to be rough either way but it turns out they were quite accurate.

I calculated that I was making only 350bhp and about the same in torque at the crank, which was underwhelming for sure. I wanted to determine if this was really the case before I definitively decided to go to the trouble of replacing the wastegate immediately. To that end, I went to a Mustang dyno run by a shop with a reputable guy who doesn’t tamper with the factory settings of the dyno. People argue all day long about the accuracy of dynos (and frankly they can’t ever be totally accurate), but Mustang dynos tend to be the most accurate as long as they aren’t tampered with. They can be made to spit out pretty much whatever result the tech wants. The dyno I went to is not adjusted and I did NOT tell them anything about my build or what I expected very intentionally, so that they could possibly skew the results…. And the results wound up being pretty spot-on consistent with my calculations.

IMPORTANT NOTE: The calculations I mentioned above were for HP and TQ at the crank and the dyno measures at the wheels. The below results at the wheels translate pretty much exactly to my calculations for crank figures.


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DEFINITELY underwhelming, but not unexpected with a failing wastegate. After I addressed that and got a new tune revision, I did the same calculations and estimated just north of 400bhp / 380ctq. The boost data also shows that I reach peak boost at least 500RPMs sooner which goes to show how badly that failing wastegate was impacting my turbos spool. My first tune with bad wastegate was making 24PSI peak and since the wastegate was wide-open at that point the turbo was working extremely hard just to make that amount of boost. Now with a working wastegate I make MORE power with LESS boost (22PSI peak) because the turbo is making the boost effortlessly. I have NOT yet gone back to the dyno to confirm the new power figures because I’m confident enough that those calculations are close as they were before and I frankly don’t care enough to spend money for complete confirmation. The power is a night-and-day improvement. I will get another dyno test eventually, it’s just not high on the priority list.




***THIS POST IS CONTINUED IN POST #13***
 

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Discussion Starter #13 (Edited)
***THIS POST IS CONTINUED FROM POST #12****




Some Points on Stock Engine Internal Limitations

After reading the last post you might be questioning how I have managed to reliably make 400bhp / 380ctq on an FSI (BPY) motor with completely stock internals, for over 1.5 years so far with heavy abuse like the kind at race tracks. The truth is there’s actually nothing special about it.

See, the problem is that there’s a lot of misinformation spread around forums and elsewhere about what these engines can really handle with stock internals and we’re going to dive into some of that. Before we can have that talk though we need to clear up what horsepower actually is and what it should and should not be used to determine (because it is misused a lot).

HP is only a theoretical figure that is derived from torque (specifically HP = TQ x RPM ÷ 5252). TQ is the REAL figure because TQ is an actual observable, acting force in physics. The motor produces a certain amount of TQ at the crank and then a certain amount of that force (after accounting for drivetrain parasitic losses, etc.) actually goes to the wheels; we call this crank torque (CTQ) or wheel torque (WTQ). TQ is what acts on ANY component of the car that is subject to twisting/rotating force (not all engine components). Crank HP, also known as brake horsepower (BHP), is just mathematically derived from TQ as seen above. If you’re following along then you may see why it is unacceptable to use HP figures to determine the limitations of an engine’s connecting rods (the weakest link of the 2.0T and many other engines) because the con rods are subject to the same rotating force as the crankshaft they are connected to, which means TQ is the proper (most accurate) figure to use to cite their limitations. However, for parts that are not subject to rotating force (e.g. pistons, valves, etc.) HP is acceptable to use because those parts’ weaknesses are typically things like heat, cylinder pressures, etc. so HP can be used perfectly fine as a frame of reference for approximately where you can start running into reliability issues. Simply due to the nature of the math mentioned above, TQ is the best figure to denote low and mid-end power and HP is the best figure to denote top-end power. TQ gets you ripping off of the line, HP helps you follow-through after you get up to speed and start hanging on to longer gears, spending more time in the RPM range above 5252 (due to the arbitrary way somebody chose to calculate HP).

That said, many people espouse that the stock connecting rods of the FSI platform can only handle up to 350ctq. I’m here to tell you that is plainly NOT true. In reality, the stock FSI con rods have the potential to handle around 400ctq fairly safely for a decent amount of time (if your definition of decent is a few years or less). I’ve even know of some FSI motors surviving track abuse for a year or two at 420ctq but that is the absolute ragged edge if you ask me. And as for the 2.0T TSI platforms, they have even more robust rods so you can add about 50ctq to the numbers I stated above.

Don’t take these figures at face value though because the above is assuming that some other variables are just right; there’s more than just the numbers behind this risk equation. The condition of your rods, their level of fatigue essentially, plays a huge role in their torque threshold. The only window you have into this is the mileage on them, type of driving they have coped with, and your engine maintenance practices.

The size of turbo plays a HUGE part in how much torque the stock motor can handle because it determines how quickly the torque comes on. The larger the turbo, the more gradual the torque curve which not only can be safer for the powertrain and drivetrain, but also aids in traction issues. For instance, a K04 tuned for high octane (100+ octane), using water-methanol injection or ethanol, can put out comparable torque figures to my current setup (with 93 octane pump gas), but the torque would come on faster for the K04 setup; that K04 setup described above is therefore actually more dangerous (and also a hell of a lot worse for traction).

Some also worry about the reliability of the pistons, however, the stock FSI pistons are forged and typically considered good on typical setups that are around the 500bhp mark. That’s a generalization though and there’s always more to it, just like with the rods. Heat is the biggest killer of the pistons and so a very well sorted and well running build at 500bhp with good combustion temps and lower cylinder temps (as low as feasibly possible on such a build) will fare well for awhile. The crankshaft, bearings/journals, etc. can also manage. All components of the head will typically manage under that mark for some time too, however you may encounter exhaust valve float on some builds that are above ~400bhp depending on turbo and exhaust manifold setup.

If you take away one thing from this section it should be that nothing is guaranteed. In the end, determining how far to push the limits comes down to knowing your car and the components, deciding how reliable you want it to be/how long you want the stock internals to last, and your general risk-tolerance. If you have very low risk tolerance and want a good balance of power and reliability for as long as possible then a 350ctq setup (even on a pretty fast spooling turbo) is totally safe if the rods aren’t fatigued from substantial mileage or poor maintenance over their lifetime. People who are open to medium-high risk (but not the ragged edge), are confident in their setup, and don’t mind possibly rebuilding an engine in a few years, can aim for more like 380ctq as I did. Anything beyond that is probably asking for trouble sooner than later. Remember, add about 50ctq to the above if you have a TSI (2.0L, not the newer 1.8T TSI)

It’s not all about hardware though, software is a significant factor in the game too, because software has a large part in determining the conditions the hardware are going to have to live with. Some tuners try to squeeze most of the power out of boost while others try to get more power by pushing the envelope with timing advance more than boost. A good, safe tune balances both boost and timing because pushing either too far is dangerous. They both basically end in excess heat if pushed too far. High boost means more air flow which means more fuel to compensate and the amount of fuel/energy in the combustion event directly increases heat generated and absorbed by engine components because that energy has to go somewhere. It also means higher cylinder pressures which means heat; both pressure and heat are hard on components. Lots of timing advance is actually fine just so long as it isn’t so excessive that it causes detonation/knock or more than a couple degrees of timing pull (although ideally none). When detonation/knock happens, the engine detects it and “retards” the timing (slows it down) for safety; this scenario goes hand-in-hand with excessive heat generation.

HEAT IS A KILLER! So a good tuner that knows how to write a good tune that makes the most of a given setup’s hardware by way of a balanced and precise approach to boost and timing (and fueling for that matter) will avoid unnecessary heat generation which will definitely prolong the life of engine components.


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Fluidampr

One upgrade that can theoretically help the stock engine (or any engine configuration for that matter) to survive more strain is an upgraded harmonic balancer/crankshaft pulley unit; enter the Fluidampr pulley. On the 2.0T platforms the crankshaft pulley performs double-duty as a harmonic balancer which does its best to absorb vibrations that travel through the crankshaft from both engine operation and some transmission component operation transferred through the flywheel which is on the other end of the crankshaft, opposite the crank pulley. The inside of the factory crank pulley has an “elastomer” material that absorbs vibrations/engine harmonics. Independent tests and Fluidampr’s own tests show that the factory crank pulley does a fine job at balancing these at low and mid-range RPMs but a pretty poor job at high RPMs, especially on setups with high-strung engines due to increased power demands and also those with lighter weight flywheels on the other end of the crankshaft. A very high-strung engine with high enough levels of vibration/harmonics can be counterproductive to power output; conversely, a smoother running engine make power more easily/efficiently. We’re not talking about substantial differences here, mind you; the impact of engine vibrations/harmonics on engine efficiency is a nuanced subject that is pretty far down the list of priorities for power output in the grand scheme of things, but it still shouldn’t be ignored. An engine with less vibrations/harmonics as it operates, especially in high RPM ranges which are by far the most stressful conditions, will theoretically be healthier longer too. I believe I have a pretty good working understanding of the actual mechanical/physical forces at work here and why the above explanations are the case but I certainly wouldn’t claim to have an expert’s understanding so I’m not going to chance overstepping my bounds with any micro-details on WHY the above statements about engine efficiency and health are true. As I understand it, through research, they stand on their own merit as generally accepted fact.

Now, as for the Fluidampr… the inside of the Fluidampr pulley, as one might expect given its namesake, contains a viscous fluid material. Again, some independent tests and Fluidampr’s own tests agree that this material has no advantage over the factory material at absorption/balancing at low or mid-range RPMs because the factory unit is already pretty good at that. In fact, I recall some tests showing that the Fluidampr may be just a little bet worse at this during low and mid-range RPMs and, consequently, in that test the engine made slightly less power at those lower RPMs too (like 3-5hp less).

As a test methodology purist (due to my background in sciences and now software development, both of which involve – or should involve – stringent test methodologies), I am skeptical of the validity and generalize-ability of test results that show such small differences. There are countless factors that the testers could have failed to control for, despite their best efforts, that could lead to such a small difference in results. I’m personally content NOT to hold those results against the Fluidampr and, instead, suggest that the most reasonable, generalize-able conclusion is that the Fluidampr works just as well as the factory crank pulley in low and mid-range RPMs. However all tests show a statistically significant improvement in performance at high RPMs with lesser engine vibrations/harmonics and power gains anywhere from ~10 – 20hp at the crank. While the exact numbers can easily be debated on the same premise as I brought up above, the results can’t be ignored altogether and the reasonable, generalize-able conclusion is that the Fluidampr is the better part for high RPMs. For my part, I have found ample reason to agree with that conclusion based on my own experience with the Fluidampr on my car as well.

To that end, I would at least recommend the part to anyone who has a big turbo application of any kind because even smaller-sized “big” turbos like mine live in the upper RPM range so, naturally, that is where you will want to be often. I would say the Fluidampr is still a worthwhile upgrade for K04 owners, perhaps even stock turbo owners, but I’d simply suggest that they prioritize their money on this part versus other, possibly more important, parts. At the end of the day, it also comes down to the individual owner’s driving habits too, though. While stock turbos and even K04 turbos make the most power in the mid-range RPMs and technically aren’t efficient in the high RPMs, some driver’s rev them out to redline often anyway. In that case, the Fluidampr would still be a good idea.


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Fueling the Beast

One of the biggest limitations of the FSI platform is the stock fueling system. It is pretty pitiful. The 2.0T TSI has significantly better fueling (both low pressure end and high pressure end) and can allow for adequate fueling of a GTX2867R turbo to at least half of its power potential, though to maximize its power potential would require upgrades. As for the FSI, well it requires pretty much everything to use such a turbo to really any potential at all.

We start with upgraded injectors. There are, of course, two very common injectors upgrades that most everyone knows about: S3 injectors and RS4 injectors. The S3 injectors (which are the same as Golf R injectors) are typically sufficient to max or nearly max a turbo the size of the GTX2867R. These injectors are good for setups in the range of 500bhp on the FSI platform, but not more (not without auxiliary fueling from water-methanol or port injection anyway). The RS4 injectors are capable of a bit more but not substantially more. However, the S3/Golf R injectors are the better choice if refinement is a concern because their spray pattern is very, very close to that of the factory injectors, whereas the spray pattern of the RS4 injectors is not. This is because the RS4 injectors, being designed for the RS4 of course, are designed for substantially higher fuel rail pressures than the FSI fuel rail will typically see (even on very modified setups). So the fuel passing through the RS4 injectors on an FSI is not passing through at the pressures the injector is designed for, which impacts the spray angle, which thus impacts start-up and idle quality at a minimum. I’m told this can be worked around by a competent tuner that is used to tuning with these injectors but I can only see that being partially true. I suppose that increasing the specified rail pressure and/or injector duty cycle for idle may help narrow the spray pattern somewhat but I just don’t see a physical limitation like that being totally tuned around.

Anyway, that said, I went with the S3/Golf R injectors and they’ve done the job so far.


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For the FSI, the high pressure fuel pump (HPFP) is something that needs to be upgraded as well but I already went over that in a previous section since it is required even on some stock turbo tunes. My low pressure fuel pump (LPFP), however, was still stock when I went BT so I had to upgrade the lower pressure side too. There are a few options for that. First, and worst, is to keep the factory LPFP and other LP components and simply add a Torqbyte PM3 controller to boost the amps to the factory LPFP, thus allowing it to flow more fuel than it does with the factory pump controller alone. I’m not sure this would even be sufficient to properly fuel a turbo like the GTX2867R to its max potential though, never mind anything at all bigger. It would also be a short-lived solution as pushing the factory LPFP this hard would lead to a premature demise from, you guessed it, overheating. Soooo many things when it comes to car failures come back to heat!

A perfectly viable option is to add an auxiliary in-line fuel pump which will boost the fuel pressure AFTER the factory pump. There are a number of options on the market for this approach and they typically allow for fueling that is much more than sufficient for a modest sized “big” turbo like a GTX2867R. Guys running turbos that are quite a bit larger use these kind of pump setups.

I went for option three: an RS4 fuel pump retrofit. It was the cheapest (only by a small amount) and it was also recommended by my tuner; ultimately, you sometimes have to bend to your tuner’s preferences. This option is basically just transplanting the guts of an RS4 LPFP into a basket that fits it and everything else together properly, including the integrated fuel filter (specific to the B6 Passat platform – Mk5 platforms have an in-line filter). The factory LPFP controller works perfectly with this retrofitted pump. This setup has been more than sufficient so far and should likely be more than sufficient for maxing this turbo. If for some reason it is not, then it would be a limitation of the factory pump controller NOT the pump itself so that could be easily rectified with a PM3 unit to boost power to the LPFP like mentioned previously (except this would NOT overheat the LPFP because this RS4 pump is designed for greater demands/amperage than it is currently getting with the factory controller)


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The last fueling-related upgrade was a simple, but sometimes overlooked one, that I should bring attention to: the fuel rail pressure relief valve. This little valve on the fuel rail under the intake manifold is a relief valve to bleed pressure out of the fuel rail if it gets too high. The factory FPRV is designed to crack open at around 130bar which is typically sufficient for factory turbo tunes and even some K04 tunes. Actually its even sufficient for low-to-mid output big turbo tunes like mine even. Since I have higher flow injectors then factory and since I’m not pushing this turbo all that hard right now (for the sake of my engine) my fuel rail pressure is actually lower than it was on APR stage 2+ tuning. I was right on the line of 130bar with APR stage 2+ but on this GTX2867R setup I’m at 118bar. Again, these S3/Golf R injectors don’t need as much pressure behind them to get a lot more fuel into the chamber. HOWEVER, when I later build my engine and seek to max my turbo, I’ll definitely be pushing fuel rail pressure that exceeds what the factory FPRV can handle.

It’s also worth noting that the FPRVs are somewhat notorious for weakening over time and beginning to open prematurely at lower rail pressures. I did not have this issue, but I have helped plenty of people diagnose fueling issues that wound up being due to a weakened FPRV. So when running a mildly or highly modified setup, it is typically wise to get ahead of the curb by upgrading this part. A common upgrade is the RS4 FPRV. As mentioned previously when discussing the RS4 injectors, the RS4 injectors, fuel rail, and of course the FPRV, are all designed to operate at pressures that are a good deal higher than the FSI. I wasn’t able to turn up info on the exact pressure rating of the RS4 FPRV though so I went with another option. I bought a 155bar-rated FPRV from a site I have since forgotten the name of but I wrote down in my build list that it was from a company called Tork Motorsports so I guess it was something along those lines. There’s also an FPRV rated for the same that is offered by APR which I wasn’t even aware of at the time.




More Intake Air Volume

I currently have the Integrated Engineering intake manifold. I am only aware of two offerings for this part, IE’s and HPA’s (though I have no doubt there are lesser known ones out there). My choice was made easy because I had a friend willing to sell me his IE manifold for almost half the price of retail. That was a VERY large part of my decision to even “upgrade” the intake manifold at all; as you may have noticed I put that word in quotes so there is definitely some subtext we need to discuss about intake manifold “upgrades”. However, let it be known that if I had ever decided to pay full retail for one I would have gone with the IE manifold anyway. Not only does their product description inspire more confidence in terms of the R&D that they performed for the design compared to that of HPA, but I also came across some information that suggested HPA actually acquired their manifold’s design from a much smaller company/shop. Now, I’m not saying that small businesses/shops/fabricators can’t necessarily put significant and SCIENTIFIC R&D into their designs, but the chances they can afford to (since it requires very expensive test equipment), or even desire to for that matter, are not high chances. If it is true that HPA acquired the design in such a way, and since I couldn’t find any info to suggest that HPA did any R&D or minor re-engineering of their own after acquiring the design, this called into question whether the HPA manifold could possibly be as well designed as the IE counterpart. I am not saying I have definitive proof of any of the above, but even the possibility was enough to sway more towards the IE manifold which I figure has to be at least as good at worst anyway. Here is some eye-candy before I dive into the technical stuff haha


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In a way, the above is splitting hairs though because here is my input on upgraded intake manifolds…

I’m going to cut right to the chase and point out that there are VERY FEW reasons to upgrade the intake manifold and doing so is not the least bit necessary on the vast majority of builds, even most big turbo builds, unless they are very big (e.g. in the GTX35-series ballpark, and if you read my previous section about turbo selection criteria you know I think a turbo that large on a 2.0L engine is assinine). Also, an upgraded/larger intake manifold is, in fact, counterproductive on K04 and smaller BT builds. The significantly larger volume of larger intake manifolds leads to lower volumetric efficiency in the charge air loop. That’s a fancy way of saying that it makes it more difficult for small-ish turbos to compress the space and, therefore, increases turbo spool time/lag and decreases low/mid-range power. This is simple physics and no amount of talk about special tuning or other smoke in mirrors from IE and HPA, whom both advertise K04 tunes to pair with larger intake manifolds, should convince you that a larger intake manifold won’t increase turbo spool time. It is a fact that it will, point blank. Only a turbo that is large enough to compress this increased volume almost instantly anyway, will not suffer from increased lag.

Based on my heavy research, which consisted of getting as much concrete information (any numerical data/graphs related to builds with and without larger intake manifolds compared to each other across a range of turbo sizes), I deduced with as much certainty as possible for someone in my position, that my turbo would be just on the cusp of large enough to compress the increased volume of an upgraded intake manifold (e.g. IE and HPA) with little to no increase in lag. This was nothing more than educated guessing at the time, however, it turns out I was pretty much right on the money because after I corrected the initial wastegate-related issues I had with my setup (as detailed in my previous post), I did confirm that even with the IE manifold installed my turbo was behaving only slightly less efficiently compared to what would be expected based on the turbos published compressor maps. That could be attributed to any combination of the perfect conditions that Garrett ensures when publishing compressor map data and the larger intake manifold plus the very large intercooler (more on that later). This was a good result!

You might be thinking: “wait, so if a turbo as small – in the grand scheme of things – as a GTX2867R is able to neutralize the volumetric efficiency concerns for a larger intake manifold then why did you suggest that they should only be considered as a necessity for turbos that are substantially larger like a GTX35-series turbo?”

An astute hypothetical question, reader. The subject I brought up was about necessity though. And while it is true that a relatively small BT can neutralize the volumetric efficiency concerns of larger intake manifolds, it is also true that the factory intake manifold is FAR from a restriction on those same setups. BT builds with turbos much larger than mine, even those in the GTX35-series territory, have been shown time and time again to flow properly with the stock intake manifold (as long as the factory intake runner flaps are removed for those on the FSI platform). Likewise, larger intake manifolds have been shown time and time again to only achieve significant/noteworthy gains in high RPMs in more realistic applications, not perfectly designed tests by their manufacturers. That depends somewhat on the size of the turbo and its CFM capability but on average I’d say noteworthy gains aren’t seen until 6,000RPM and up.

What this boils down to is that larger intake manifolds should NOT be considered as a primary means to increase flow and thus power; rather, they should ONLY be considered as a means to increase flow and thus power if you specifically do NOT want to simply get a larger turbo and if you DO want to be able to squeeze a little extra out of the setup you have/have chosen IF your setup is already being maximized and IF the turbo is large enough to compress the extra space without increasing lag and decreasing low/mid-range power.

As you can see, the above is a set of highly contextual criteria; there are a lot of “ifs” in there. Not everyone’s build/plans will meet those criteria and, even if they do, I still hold to what I said about the “necessity” of a larger intake manifold because at that point it becomes a cost-to-benefit calculation more than a strict necessity. However, in my case, I did meet those criteria. I specifically did NOT want a larger turbo than a GTX2867R because turbo lag is especially detrimental for track cars; however, I did want to “future-proof” my build in the sense that I wanted to be prepared to squeeze as much out of the setup as possible someday and I knew that I was trusting that I would not have any noteworthy volumetric efficiency concerns based on my research. But MOSTLY, as I said earlier, I was just enticed by the opportunity to get the manifold for almost half of retail.

Also, in the spirit of future-proofing, I foresaw that I would probably eventually need to run water-methanol injection and the IE manifold comes pre-tapped for direct port injection in each runner of the manifold (whereas you have to get it special-made that way from HPA). The stock manifold can be tapped for DPI WMI too but I just used this as another excuse to justify buying the IE manifold. I guess it doesn’t hurt that it looks nice too (although I’ll give HPA’s manifold the distinct edge in aesthetics).

Was it worth it? Nope. Definitely not so far. Will it be worth it in the future? Perhaps. For one thing I am going to be setting up DPI WMI in the not to distance future (in prep for 2020 track season). As for whether the IE manifold will ever be paramount for realizing additional gains with my setup that I couldn’t have already achieved with the factory manifold and a relatively small BT… we shall see but I don’t hold my breath for it.




***THIS POST IS CONTINUED IN POST #15***
 

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Discussion Starter #15 (Edited)
***THIS POST IS CONTINUED FROM POST #13****




Better Air cooling

There are a lot of things to take into consideration when it comes to selecting the best intercooler (hereafter referred to as “ICs” for brevity). Of course money is one of the biggest considerations because there are ICs ranging from $250 to over $1000 for VW turbo platforms like the 2.0T platforms. In any case, but budget is a personal decision so I won’t get into that; I will aim to explain all the other factors fully enough so that one can make the best decision within one’s budget.

1) Mounting location:
That having been said, the first major factor is the desired mounting location, which itself has implications on the size of the IC’s core (another major factor in its own right). As many readers are probably aware, there are 2 viable mounting locations for upgraded ICs: the stock location and a “true” front-mount location, which refers to an IC that is mounted in front of the AC condenser NOT behind it (like the stock location), typically very close behind the front grille. As both of these locations are technically front-mounted I will refer to the latter of the 2 as a “true” front-mount just to be clear.

Ask a majority of folks in the modded VW community (or probably any modded car community for that matter) which of the 2 types are better and most will tell you the true front-mount IC is better. If you’ve read much at all of my build thread then you know what I’m going to say now…. It’s just not that simple. There is more to it than the mounting location.

Yes, the true front-mount IC DOES indeed get greater and colder air flow because it is right up front behind the grille INSTEAD of sandwiched between the AC condenser and the radiator like any stock-location IC. That also plays to the advantage of the true front-mount IC doubly so, because since the stock-location IC is sandwiched between 2 other heat exchangers its efficiency can have a parasitic (negative) relationship with the others, mainly the radiator because there is VERY little space between an upgraded/larger stock-location IC and the radiator. While that last specific point is typically only a major concern in track applications, it is still worth mentioning. It would seem, then, that the true front-mount IC is best... BUT...

2) Core size:
Those advantages of the true front-mount IC come at major costs. All true front-mount ICs are substantially smaller than upgraded/larger stock-location ICs. The average upgraded stock-location IC is about 3X taller than the average true front-mount IC and at least 1 inch narrower. Both of these characteristics are advantages to the stock-location IC. We’ll discuss the height advantage now and we’ll discuss the width (or rather the narrowness) advantage later as it pertains to a separate factor. At the end of the day, an intercooler is simply a heat exchanger so, like any heat exchanger, the biggest – or at least one of the biggest – factors in its performance is its mass. The greater the mass of an object, the greater its thermal capacity per unit of time. The greater its thermal capacity per unit of time, the more heat it can dissipate (exchange) into the air around it, and more quickly. For this reason, any upgraded stock-location IC has a MASSive (pun intended) advantage over any true front-mount IC, with regard to heat dissipation potential. So massive, in fact, that this advantage alone is enough to allow an upgraded stock-location IC to perform as well or even better, in some cases, than a true front-mount IC, despite the true front-mount IC’s other advantages mentioned previously. There was a qualifier in that last statement, though, so let me explain what I meant when I said an upgraded stock-location IC can perform even better “in some cases”… it can perform better IF air flow to the IC is sufficient to somewhat negate the inherent advantage in the true front-mount IC’s location while ALSO accentuating the advantage of the upgraded stock-location IC’s mass advantage. So, in other words, at low speeds even the greater mass of the upgraded stock-location IC may not be enough to outperform its rival because it heat-soaks worse being between other heat exchangers that are heating up the surrounding air, BUT as soon as you get moving at medium or high speeds the advantage goes to the upgraded stock-location IC.

3) Core design:
That is, of course, all assuming that we’re comparing ICs of relatively close design efficiency and quality. Such should always be a considered factor when comparing parts, so we will discuss that too. There is much talk of the 2 major IC core design types: bar-and-plate vs. tube-and-fin. You’ll probably see it universally agreed that bar-and-plate is the superior design. In most ways, that is true. For one thing, bar-and-plate is indisputably the more durable design (giving it an edge when it comes to resisting damage from road debris). It is also often the more efficient design for doing its job at heat exchanging. However, that’s where it gets a little wishy-washy. What most people don’t realize is that there are different subtypes of tube-and-fin design. Some are better than others. Extruded tube with squared and louvered fin design is the best among these subtypes. When you buy an IC from a top-rate company that deals exclusively with intercooling products you will probably get that type of tube-and-fin design, which is actually capable of cooling performance that easily competes with that of bar-and-plate design; however, it’s still unquestionably less durable than bar-and-plate. Durability would matter a lot more for a true front-mount intercooler, but for an upgraded stock-location intercooler it is almost irrelevant because the AC compressor is shielding the stock-location IC from debris (unless of course you’ve removed your AC system). But, in essence, the bar-and-plate vs. tube-and-fin debate is missing the bigger point, which is that it has less to do with the core design in and of itself as it does with the quality of the part's design. Buying an IC from a top-rate company that deals strictly in intercooling should almost always be given precedence over buying and IC from a company that makes a little bit of everything that the aftermarket community demands/requires, especially if you can confirm that they use bar-and-plate OR extruded tube/squared and louvered fin design, because you’re likely to get better R&D and tested performance from the former company than the latter company. There are, of course, exceptions to that rule; for instance, APR and IE are known to put in substantial R&D to their products (primarily because they can afford to), despite the fact that they are not strictly an intercooling company.

You might be asking: “why would I buy an intercooler that uses extruded tube/squared and louvered fin design, even if it is from a company that specializes in intercooling, if it doesn’t have a distinct efficiency advantage over bar-and-plate, and is definitely less durable?” Another good hypothetical question. The answer is because, even as specialized as it is, the extruded tube/squared and louvered fin design is cheaper to produce so you save money and get the same performance. And again, you should only really be concerned about durability if you are looking at a true front-mount IC or deleting your AC condenser that shields the stock-location IC.

4) Pressure drop:
There is one last factor to consider when it comes to choosing an IC, referred to as pressure drop. Every charge air system, including the factory system, has some degree of pressure drop between the turbo outlet right after air is pressurized and the intake valves of the engine where it is ultimately fed. During normal operation, we cannot nor do we focus on measuring/considering pressure drop in the last stretch of that path because our ECUs get boost pressure data from the manifold absolute pressure (MAP) sensor about halfway up the throttle body pipe BEFORE the throttle body and intake manifold. In any case, the boost pressure difference read from the MAP sensor and, say, an analogue boost gauge tapped into the intake manifold would be pretty negligible anyway. That is because a majority of pressure drop comes from the IC (and sometimes its charge piping).

So what this pressure drop means is that you might be seeing, say, 22PSI in your data-logging or on your boost gauge but your turbo is actually making, say, 24PSI at its outlet. The difference of 2PSI is lost in the charge system after the turbo. That is incidentally about how much pressure drop the factory charge air system has so if you have a stock turbo, stock IC, and stock charge air pipes, that are all sealed tight then you can expect your turbo is making about 2PSI more than what you see in data-logs or a boost gauge. The goal of any upgraded charge air cooling system is to not stray much from that amount of pressure drop because 2PSI pressure drop across the whole charge air system is pretty good, it doesn’t get much less than that.

There are multiple causes of pressure drop but, ultimately, what they all have in common and what pressure drop really all boils down to is loss of kinetic energy in the charge air stream. On the average setup, at least 50% of pressure drop is lost from the IC itself and basically all of the rest is lost in the charge air piping to and from the IC. We’ll start by assessing the main things that influence pressure drop in the charge air piping since it is simpler.

For the most part it comes down to how many bends there are in the charge air piping, how severe the bends are, the length of the piping, and size of the piping (typically measure by inside diameter). At the surface, it is probably pretty intuitive how loss of kinetic energy of the charge air stream, and thus pressure drop, occurs as the number of bends and the severity (angle) of those bends increase but let me break it down. Since the charge air stream has momentum and inertia, like anything else with mass and velocity, it will tend to slam into bends rather than flow perfectly around them; this becomes more and more exaggerated for sharper angled bends, of course. These bends represent a decrease in velocity, thus kinetic energy of the charge air stream, and thus pressure drop. Bends in the charge air piping should as few as possible and as gradual as possible. As for the subject of piping length and size, it’s a little more subtle. In this case, what we are concerned with is surface area itself. Yes, even the smooth surface of charge air piping is a contact surface that represents loss of kinetic energy for the charge air stream because oxygen molecules like to attach themselves to surfaces. You can observe this with your own eyes when you bleed your brake calipers; any air bubbles in the system tend to cling to the side of the hose leading do you drain can (and likewise they like to cling to the inside walls of your calipers which is why it is recommended to tap the calipers with a mallet while you bleed brake systems). This tendency of air does not have as dramatic an effect on the loss of kinetic energy/velocity/pressure in the system as does the bends in the charge air piping, but it should still be considered.

You may have realized already that all the things we have discusses so far that deal with pressure drop in the charge air piping itself, go in favor of an upgraded stock-location IC rather than a true front-mount IC; true front-mount ICs typically require about 2x as much charge air piping length and despite the best efforts to reduce number/angle of bends they will almost always result less favorably than the simple charge air piping to/from a stock-location IC.

Lastly we must consider pressure drop of the IC itself. The root cause is the same as what we discussed previously; loss of kinetic energy/velocity. In the case of the IC, however, the subject of surface area is a bigger focal point than in the case of the charge air piping. While the substantially larger surface area of the upgraded stock-location IC worked in its favor for cooling efficiency, it most certainly does NOT work in its favor when it comes to pressure drop for the same reason that longer and wider charge air piping is unfavorable for low pressure drop. The design of the core is a factor too. Bar-and-plate design cores are smoother than tube-and-fin cores and so they have an advantage when it comes to pressure drop. The rougher tube-and-fin design perturbs the air flowing over its surface and more kinetic energy/velocity is lost this way. However, the higher end extruded tube/squared and louvered fin design, discussed previously, is reputed to minimize this to the extent that it is about comparable to bar-and-plate for minimizing pressure drop.

Since most true front-mount ICs have a bar-and-plate core, as their location demands they be more durable, and since they have less surface area you might be thinking that the true front-mount IC has a distinct advantage in terms of pressure drop to make up for its mild, overall disadvantage in cooling performance (assuming we are comparing units of comparable quality and design). Unfortunately, you’d be wrong. If you’ve somehow managed to remember that one thing I mentioned many paragraphs ago that I said I would be circling back to, you might have an inkling as to why… it turns out that the fact that the true front-mount IC is quite a bit thicker than upgraded stock-location ICs pretty much negates its other advantages in terms of pressure drop. Velocity is decreased through wider spaces and, conversely, it is increased through narrower spaces.

In the end, you will find that when considering a good upgraded stock-location IC and a good true front-mount IC the pressure drop specs from inlet to outlet of the ICs themselves will tend to be about the same. The absolute best of the best achieve as low as 1PSI pressure drop (I don’t think I was able to find any in the VW aftermarket that achieved quite that low), and the worse ones tend to have around 2PSI pressure drop. Most tend to fall closer to 1.5PSI of pressure drop OR they just don’t state pressure drop specs at all. I take that to suggest their pressure drop specs are probably not favorable so I ignore ICs from companies who do not advertise their pressure drop specs.

5) Conclusion:
If the a majority of the ICs available to us (assuming you own a 2.0T platform like me), tend to have pretty similar pressure drop specs, and if the charge air piping for a true front-mount IC tends to contribute to higher pressure drop (probably at most and extra 0.5 - 1PSI) then does that mean that, on average, true front-mount IC setups have mildly worse pressure drop AND mildly worse cooling performance?... YEP, pretty much. And thus is my very long-winded but substantiated debunk of the prevalent theory that true front-mount ICs are always better. The truth is that while upgraded stock-location IC's will tend to have a minor overall edge, in general, either or can perform a little better than the other and that comes down to the numerous factors outlined in this section, which have just as much to do with IC core design, who manufactured it, and your personal setup plans, than the location itself.

It was by taking ALL of the factors I just covered into consideration that I decided on the Wagner Tuning upgraded stock-location IC. This IC boasts the largest core on the market for the 2.0T platform, as far as I’m aware. It is truly massive, a couple inches taller and wider than the APR and IE stock-location ICs, only slightly thicker, but $200 cheaper because it uses the extruded tube/squared and louvered fin design instead of the more expensive bar-and-plate. It also boasts comparable pressure drop specs at 1.5PSI of pressure drop which is definitely as low of pressure drop as you can possibly get with an IC this massive. That’s a testament to its design excellence, which should come as no surprise since Wagner Tuning is a German manufacturer that specializes in intercooling products. Despite the enormity of this IC it is a bolt-on replacement as long as you have a factory radiator. I confirmed that during install by sizing up with the factory radiator in place initially. However, I did ultimately put in a larger radiator too and that required some modification/trimming of the RADIATOR corners (which you can see below) but the IC did not have to be touched.


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Better Water/Coolant Cooling

It is a fact that more powerful cars produce more heat. Even naturally aspirated cars without turbochargers adding lots more heat, are still subject to this rule. More power requires more fuel and more fuel burned directly translates to more energy released in the form of heat which the engine absorbs. Engines that derive a lot of their power increases from turbochargers are substantially more subject to heat management issues because on top of the engine itself running hotter from increased fuel demands, turbochargers get extremely hot from the energy it takes to compress given volumes of air into much smaller space (which makes me think about the macrocosmic example of the immense heat generated when gravity compresses large volumes of gases into a much smaller space to form a star). Compression is “expensive” in terms of energy which takes the form of heat in this case (and most cases)

So with that understanding in mind, and also considering that I had chosen the massive Wagner Tuning stock-location IC, I decided it’d be wise to upgrade my radiator too so that water/coolant cooling, and thus engine cooling, would be better. After all, the Wagner Tuning IC would block more air flow to the radiator do to its taller, wider, and especially thicker core. For the same reason it would also be physically closer to the radiator which would result in them heating up the air between them more and less fresh cool air between them which is not ideal for heat exchangers.

Much like an IC upgrade, an upgraded radiator is physically larger, has a larger core, thus more fluid capacity, and also has aluminum end tanks unlike the factory radiator. Additionally, upgraded radiators typically have dual-pass cores which means the fluid going through the radiator passes through the core twice and thus spends 2x as long in the core. All of these factors equate to a better performing radiator. A physically larger core is favorable for exactly the same reasons explained in the previous section about air cooling with ICs and more fluid capacity is an advantage for the same reason as well; more fluid means more thermal capacity to absorb engine heat and carry it to the radiator to be dissipated. Aluminum end tanks are not only more durable but aluminum also conducts heat about 5x better than plastic which means the heat trapped inside the radiator escapes to the outside to be dissipated into the air 5x more efficiently, therefore the factory radiator end tanks trap a lot more heat. Lastly, the more time the fluid passing through the radiator spends in the radiator core itself, the more heat is dissipated in total.

There are a handful of compatible upgraded radiators but the 3 most readily available and well-documented ones are from TyrolSport, CSF, and Mishimoto. If judging these options based on the criteria presented above then the TyrolSport is indisputably the winner. It’s larger, has the greatest fluid capacity increase, etc. It’s also almost definitely the highest quality of the 3; in my experience any that of everyone I know, TyrolSport makes quality pieces no matter what it is. However, it’s also 4x as expensive as the others and so that was immediately off the table. I was already over-budget at the time, as always seems to be the way of these things, and a $1100 radiator was just not in the cards. Even if I didn’t have a budget, I have very serious doubts about whether the TyrolSport radiator could possibly be that much more efficient as to justify 4x the cost. In my mind, not a chance. I compared the specs and design of the radiators closely and they aren’t that much different. Overall build quality, machining quality, and the cost for a smaller operation like TyrolSport to R&D such a piece are what I believe to be the real reasons that radiator costs so much more, not that it inherently performs so much better as to justify 4x the cost. Now, unfortunately, at the time that I was selecting parts for this project, back in 2018, I was somehow not aware that CSF made an upgraded radiator. I knew of CSF for their factory replacement radiators but I did not know that they made a full aluminum upgraded version very similar to the other 2. If I had, I would have chosen that without much hesitation. The price rivals that of Mishimoto at $250-$300 and CSF manufacturers some OEM parts for German auto manufacturers, with a solid reputation for quality. It’s hard to find any bad things to say about CSF. Not so in the case of Mishimoto. You’ll find plenty of good and plenty of bad feedback about Mishimoto. So it was with some reservation that I bought a Mishimoto upgraded radiator.

As far as I could find at the time, the only major concern about the Mishimoto radiator was that they had a penchant for leaking at the quick-connects machined into the inlet and outlet. After consulting with the same shop that did the fabrication work I mentioned previously in post #12, I decided I would buy the Mishimoto radiator and spend a little extra at the shop to cut off those quick-connects and weld on some standard hose barb ends. Simple enough. I figured that with that taken care of reliability concerns would be pretty minimal and the core itself should be an improvement. I even confirmed with Mishimoto, in writing, that modifying the quick connects would NOT void my lifetime warranty with them.

I’m happy to say that after 1.5 years with the Mishimoto I’ve had no reliability issues nor do I anticipate any at this rate given the abuse I’ve put the part through. I was told later by a guy I generally trust from a VW specialty shop that these radiators also have a reputation for core leaks, something I hadn’t found in my own research previously.

Bottom-line: it seems a Mishimoto radiator is taking a gamble. It might turn out fine, it might now. The do have a basically no-questions-asked lifetime warranty but then there isn’t really much point in taking a gamble when CSF offers a radiator with nearly identical specs for the same price and is reputable as an OE supplier for some German autos


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Retrospective on PERFORMANCE of Wagner Tuning Intercooler & Mishimoto Radiator

You may have noticed that I refrained from commenting on my actual experience with the performance of the Wagner Tuning IC and the Mishmoto radiator after install. That’s because I was saving those details for this separate section.

I’ll admit, this section is a little “fluffy” as a chunk of it is just relaying all the things I observed as time went on with my use of the Wagner Tuning IC and Mishimoto radiator. If you want to skip to the meat of the matter, you can skip to the “conclusion” paragraph towards the end.

You may have also noticed in the mods list of post #1 I noted that I removed both of them as of late 2019 (after 1.5 years of use). That’s because, despite my best efforts to consider every single facet of what constitutes good performance of these parts, I still missed some details. Actually, I think I was so focused and myopic in my research on the smaller details, specific to each of the parts separately, that I missed some bigger picture type stuff. I wasn't giving enough emphasis on how much one part (in this case the Wagner Tuning IC) can impact another (in this case the Mishimoto radiator) and how they are both part of larger systems. I’ll expand on what I mean by that and how I came to realize it more holistically.

First let me say that the Wagner Tuning IC does very well at its own job of air cooling. Even on hot Summer days, which here are easily 90F and sometimes closer to 100F, it was capable of bringing IATs down to around 10-15F over ambient, which is about as good as you can expect from an intercooler in hot weather and an engine/turbo setup that runs pretty hot in and of itself. In more mild temps like 60-70F the IC was capable of getting IATs even a little closer to ambient. This is actually very impressive. I don’t fault the IC for its performance. I only fault it because it is an impediment in the radiator’s performance.

It turns out that despite all that stuff I explained about upgraded radiators in the previous section, none of that was enough to combat the efficiency issues, and thus temperature issues, that tend to arise when you have 2 large heat exchangers right next to each other and with barely any space between each other. I underestimated the impact of having a massive and relatively thick IC (for a stock-location IC) like the Wagner Tuning IC in front of the radiator and with barely any space between them. I got my first taste of this when I noticed that after driving long enough to get the water temps (and by that I mean water/coolant mix) up to operating temperature, if I happened to be going less than about 50mph (or especially stopped in traffic) for over a minute or so, the water temps would go a good deal higher than they did in the past. I was paying close attention to the water temps with my P3Cars gauge which reads from the ECU which, in turn, reads directly from a coolant temp sensor in the engine-block (this is much more accurate than the dummy gauge on the dashboard). In the heat of the Summer on a 100F day, with the factory IC and radiator, the water temps might spike up to ~215F briefly in traffic and quickly go down with the fans running pretty lightly. That’s all pretty typical behavior. Now, with the Wagner Tuning IC and Mishimotor radiator, under the same conditions they would spike to 225F (or slightly higher on occasion) pretty much any time I was going slow or stopped and would hover that way for longer; the fans would have to run much faster and for longer too. I also noticed that same behavior with the fans whenever I would park the car. VW fans typically do run afterward, that itself is normal, but they would run incredibly fast/loud and for much longer than usual. Mind you, this would occur even if I had NOT been running the car hard at all.

At first I told myself this was okay on the grounds that it was just a natural result of the fact that I had a bigger turbo and, overall, hotter running setup with 2 large heat exchangers in very close proximity with low airflow… that may be true. I also told myself that logically they’d perform great on the track when airflow was in constant supply… that turned out not to be true and that is when I realized I had to make some changes.

My first track day with this whole setup was a pretty mild day around 75F. I had a high ratio of water-to-coolant because coolant (contrary to what its name suggests) is not good for cooling. Coolant is there for anti-corrosion and anti-freezing properties; water is what does the better cooling job. Despite this I saw peak water temps of 240F throughout each track session. It only peaked that high once that I saw and only briefly. Aside from that it was more common to glance and see the temps hovering around 230F. I’d be concerned if the temps were more consistently around 240F, but as it stands brief peaks to 240F on a setup like this are not straight-up dangerous. An average of around 230F or slightly more isn’t all that bad either. These results were just not as good as I was hoping for, ESPECIALLY on a relatively mild day and a fast track (meaning pretty good airflow). It is very likely these temps would be much more concerning during a track session on a hotter day and/or a slower, technical track. That’s why I decided something had to be done.

After more observation and more research I came to a few conclusions about what contributed to my water/coolant temperature woes. The first was obviously that the IC was blocking a lot of air flow to the radiator. The second was that my setup is very demanding on the cooling systems, especially because my tune is very aggressive with the timing advance and in certain conditions has to pull back some timing (and I believe I explained that contributes to A LOT of heat energy in post #12). But I couldn’t shake the nagging feeling that there had to be more to it than just that. Despite other guaranteed factors in these high water temps, I felt like the radiator itself might be partly to blame because even when I wasn’t driving the car hard at all water temps had a tendency to sore on average 10F more than I’d expect. After more holistic research, the third conclusion I reached was that these upgraded radiators might just be overrated. A “one step forward, two steps back” sort of issue.

See, the radiator is just one part of a whole system. Fluid flow rate in a closed loop system like this is very important. VW’s engineers design the system to certain specifications. The water pump is capable of generating a certain amount of pressure in the system, the passageways throughout have certain width and other specifications to maintain the specified pressure, and even the radiator is designed with a certain flow rate in mind. There is no empty space in this cooling system. Any interval of time that water is in the radiator being cooled, is time that other water is in the engine heating up.

After seeing the bigger picture I had an epiphany. Water spends at least 2x as much time in large, dual-pass radiators which means it can cool more but that also means water is spending at least 2x more time in the engine where it heats up more. So while everything about these upgraded radiators is designed so that the radiator ITSELF will perform better at its job of cooling the water/coolant in it, it does not take into account the rest of the system. On top of that I realized that the fin density of the Mishimoto radiator is not as high as the fin density of the factory rad which impacts cooling efficiency too.

So the ultimate question is whether or not the upsides of the “upgraded” radiator more than make up for the downsides it introduces. It would be very, very hard for me to prove one way or the other with any kind of valid test and I definitely won't be able to conduct a valid test in the 2020 track season because I have made significant changes between 2019 track season and the upcoming 2020 track season which would completely invalidate even a casual test. All I could say for sure is that my water temps were too high at the track in 2019 and something had to be done about it before track season 2020. With new observational and theoretical info, I decided that to combat the water temps I’d need to solve for the air flow blockage by the Wagner Tuning IC, the aggressive timing issues, and the Mishimoto radiator itself.

Details on my solutions for those problems, and several other unrelated 2020 track prep items, are coming in a future post when I get some more time to make it!
 

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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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Discussion Starter #17
Probably check in on this from time to time. Just got into the Passat life with my 3.6 4motion wagon. Nice build so far.
Thanks! While a lot of the parts I cover in here won’t be directly applicable to your 3.6L platform, there will still be plenty to pickup that will be useful in the course of making your own decisions on what you want to modify and how. The first post covers all the mods to date in detail. I haven’t gotten the build detail posts themselves caught up to present yet. Still work in progress. Feel free to shoot over any questions.
 

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Probably check in on this from time to time. Just got into the Passat life with my 3.6 4motion wagon. Nice build so far.
Thanks! While a lot of the parts I cover in here won’t be directly applicable to your 3.6L platform, there will still be plenty to pickup that will be useful in the course of making your own decisions on what you want to modify and how. The first post covers all the mods to date in detail. I haven’t gotten the build detail posts themselves caught up to present yet. Still work in progress. Feel free to shoot over any questions.
I’ve silently followed many builds here on vortex, and must say really like where yours is headed.
I may be new to owning a Passat but definitely not new to vw. As far as mods go to my 3.6 I don’t have too many plans as I built my 12v mk4 vr6 for having fun. Most recent dyno on 12lbs was 308whp and 362ft lbs torque. Although plan to up the boost as I just installed a bahn brenner Sri. So for my Passat I might get an apr stage 1 (only offered stage) coilovers, wheels and maybe suitcase delete. Just did the timing chains, rear main seal, torque converter seal, all the fluids, plugs, and brakes. Just got it running really good for starters. Posted it in the thread here in the b6 forum “what did you do to your Passat today” lol.
Anyways I look forward to see where this goes. Really clean b6 👍🏻
 

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2007 B6 Passat 2.0T, 1994 E36 M3 3.0L, 2004 Silverado Z71 5.3L
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Discussion Starter #19 (Edited)
I’ve silently followed many builds here on vortex, and must say really like where yours is headed.
I may be new to owning a Passat but definitely not new to vw. As far as mods go to my 3.6 I don’t have too many plans as I built my 12v mk4 vr6 for having fun. Most recent dyno on 12lbs was 308whp and 362ft lbs torque. Although plan to up the boost as I just installed a bahn brenner Sri. So for my Passat I might get an apr stage 1 (only offered stage) coilovers, wheels and maybe suitcase delete. Just did the timing chains, rear main seal, torque converter seal, all the fluids, plugs, and brakes. Just got it running really good for starters. Posted it in the thread here in the b6 forum “what did you do to your Passat today” lol.
Anyways I look forward to see where this goes. Really clean b6 👍🏻
Thanks man, that's encouraging! I'll be updating it as often as I can. Should get some time this weekend. And cool, I post on the "what did you do to your Passat today" forum here and there too. I actually have one from just a few weeks back when I did my Fall full detail and I think I had an engine bay shot from a few months ago (few pages) so if you wanna get a sneak peak at what the car actually looks like now compared to the build thread here so far you could! But I'll get the thread caught up sooner or later so you'll see either way.

That's a lot of power for 12PSI, nice! Perks of a 6-cylinder haha. What turbo setup did you put on there?

I have some mustang dyno sheets but I'm gonna wait until I get to the dyno again to post up because the ones I have now are from when I was having some wastegate actuator/boost control issues and performance was pretty **** at the time so they're really not worth posting.
 

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Yea I went ahead and checked out the spoilers for your build lol. Wow! Makes me want to go detail my engine bays 😳. Never really worried too much about it, more for function then beauty myself lol.
I have the kinetic stage 3 kit from c2. Has performed extremely well over the past 6 years.
Finally ditched my stock plastic manifold so will see how it does on 18lbs. But that still won’t be for awhile either as my bell housing has a giant crack in it lol. Probably just gonna garage it and work on it over the winter, while also trying to accomplish some small stuff on my Passat.
But it feels like I’m taking over your thread when I was just gonna watch quietly lol 🍿.
 
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