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Discussion Starter · #1 ·
Ok, there are a lot of folks out there who seem to be confusing autocross setup with road racing setup.
In autocross, BFB is your friend.
In roadrace, BF may not be your friend.
The only way to make a fwd VW not understeer is to run really high spring rates up front and higher rates out rear. You can just stiffen up the rear with a BRB, but the front outside wheel will exchange radical changes in camber during a turn. the BFB limits the amount of camber change during the turn. Good for control.
All of the folks that are preaching to run a BRB and either a stock FB or no FB are only selling you half he story. Spring rate is the other half of that story.
If you do not believe BFB has its place in Stock of SP car, then go driveone.
Manix / Wentzel were running a BFB in their FSP nationals winning car, Dude in Fla with the SM Mk1 Scirocco (G60, soon to be other supercharger) id running one. Me, I have won 7 club championships in GS GTI VR6 with the BFB with guys like GH Sharp, Rob Carpenter, etc running against me.
Do some research, and you will discover that a BFB in autocross can be your friend.
--Kevin
 

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Re: BFB debate (bluevr6)

Quote, originally posted by bluevr6 »
Ok, there are a lot of folks out there who seem to be confusing autocross setup with road racing setup.
In autocross, BFB is your friend.
In roadrace, BF may not be your friend.
The only way to make a fwd VW not understeer is to run really high spring rates up front and higher rates out rear. You can just stiffen up the rear with a BRB, but the front outside wheel will exchange radical changes in camber during a turn. the BFB limits the amount of camber change during the turn. Good for control.
All of the folks that are preaching to run a BRB and either a stock FB or no FB are only selling you half he story. Spring rate is the other half of that story.
If you do not believe BFB has its place in Stock of SP car, then go driveone.
Manix / Wentzel were running a BFB in their FSP nationals winning car, Dude in Fla with the SM Mk1 Scirocco (G60, soon to be other supercharger) id running one. Me, I have won 7 club championships in GS GTI VR6 with the BFB with guys like GH Sharp, Rob Carpenter, etc running against me.
Do some research, and you will discover that a BFB in autocross can be your friend.
--Kevin

not again.
i don't roadrace, i autox.
i run BRB exclusively. i've done the simulations, I've done the calculations, and I've gotten excellent results with it.
Anyone who thinks there's only one way to make a car handle is barking up the wrong tree.
 

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Re: BFB debate (bluevr6)

I missed something... BFB?????

big front swaybar.......
 

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Re: BFB debate (SirWillett)

Quote, originally posted by SirWillett »
I missed something... BFB?????

big front swaybar.......

yeah.
BFB = big front bar
BRB = big rear bar
 

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Re: BFB debate (bluevr6)

Like John said, I really don't think there is one set, tried and true, ultimate solution. There are however several methods that _do_ work. I run BFB on my car, and I love it (btw, the SM guy is Neal Tovsen). I've also run BRB bar as well and it has performed admirably. My own personal vote is for BFB.
I'll also say I'm tired of hearing people preach one way as THE answer (Shine) as well as many people who will recommend what they use such as "stock and a rear bar and it works great! I beat *insert car* with it!"
Use caution when determining who you listen to. Be aware of opinions of people who are speaking from street/autox experience. What works on the street, and what works for road racing, is not what works best for autocross. Period. Look for information with results behind it. The most difficult determination when dealing with the Internet is separating fact from opinion.
Speaking of results, I have no championships backing up my experience with BFB. However, BFB has lots of accolades behind it. Shine, to my knowledge, has no autocross experience. They do have loads of road racing experience. These really aren't too related except on a very general level. BRB on a national level has not won any championships, but has done reasonably well. Keep in mind however, that ALL of these cars, both BFB and BRB, are running very high spring rates, generally in the 400#-700# range. This isn't really conducive to the street, especially in a sub 2000 lb car.

I guess here is the main point:
There is a tremendous difference between road racing, having a fun street car that you autocross, and having a dedicated car that is designed exclusively to go around a tight, high transition, coned course as fast as possible in a given ruleset.
Be aware of the difference when asking questions and when giving answers.



Modified by Mhyrr at 4:59 PM 4-27-2004
 

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Re: BFB debate (bluevr6)

I don't know what got this thread started, maybe Kevin Bluevr6 is just stirring the pot.
I have never run the BFB set-up, and autocrossed successfully with a BRB for several years. I freely admit that I have no national championship, nor have I been to nationals, but I have had many regional championships, hillclimb records, and records on permanent autocross course (go-kart tracks). Based on that, here's my opinion:
The biggest factor is maintaining a stiff enough front to control camber change, then getting the front to rear roll couple correct. The wheel spring rate should be about a 5:6 ratio including springs rates and swaybar wheel rates. I chose to get to that point with swaybars on both ends. I added about 50lbs of wheel rate to the front with swaybar, and 85 lbs to the rear. If you do this with 425# front springs, and 500# rear springs, you end up very close to the wheel rates of a 400/600 BFB/NRB set-up. I found this set-up to work for me. I actually arrived at this set-up when converting my ITB car to FSP and not wanting to buy new springs.
Also, IMHO, using higher front spring rates helps control nose-dive under braking, and helps keep the car flatter (front to rear) giving better transition into the corner.
Brad
 

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Re: BFB debate (Gazornan)

Speaking as a total novice in the suspension tunig department (I've been doing a lot of reading lately trying to decide my path)...I would think the BFB like Mhyrr and Gazornan are suggesting to be a better solution to the problem my Mk3 GTI faces:


With sticky Victoracers and stock (2.0 w/plus) suspension the car just dives into corners...The stiffer front spring would do a better job keeping the car flat in the heavy braking and tight turns...though I have been lusting after the Shine set-up for quite sometime...dang nabit...back to the drawing board...
 

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Re: BFB debate (gottagti)

Quote, originally posted by gottagti »
Speaking as a total novice in the suspension tunig department (I've been doing a lot of reading lately trying to decide my path)...I would think the BFB like Mhyrr and Gazornan are suggesting to be a better solution to the problem my Mk3 GTI faces:
With sticky Victoracers and stock (2.0 w/plus) suspension the car just dives into corners...The stiffer front spring would do a better job keeping the car flat in the heavy braking and tight turns...though I have been lusting after the Shine set-up for quite sometime...dang nabit...back to the drawing board...

the BFB setup runs softer front springs.
 

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Re: BFB debate (John A)

the BFB setup runs softer front springs.
Yeah...I knew that...I can't belive you thought I didn't know that...been a long day...and I think I read everyother word

Damn..I need to read more (carefully)
 

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Re: BFB debate (gottagti)

blah blah blah blah blah.. everyone hows done any reading knows there are many many different ways to set up a cars suspension.. me i run NO bars! yup thats right non.. but then my spring rates where designed to work without a bar... so i have a little lean.. but i have some kickass front camber gain in corners!!
stop the fightin and choose your own personal route!

at the end of the day drink some
and half a
with the competition
 

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Re: BFB debate (dextervw)

Not that it matters to this discussion,but cars prepared by me have won more than a dozen SOLO2 national championships,including 4 FTD overall.SOLO isnt my main business,but if you think I ignore it or dont understand it,you are terribly mistaken.I am busy most weekends at tracks around the country,but when I have time I bring my whole family to a parking lot and go through the cones. I use an ITA Golf and with a good driver it wins Street prepared and usually beats all other Prepared and some modified cars and I can assure you that it doesnt have any front bar!! If you can make a BFB work,more power to you.I love to see it.
Dick Shine
 

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Discussion Starter · #12 ·
Re: BFB debate (bluevr6)

Ok, lets take the opportunity to beat on Kevin for extending his experience and trying to open up a more civilized debate on BFB / BRB debate.
I believe most of the responders missed to point of to post, which ws to explain the differences of the bFB or BRB position.
As for tring things out, I have spent days (not hours, days) on a friction circle with my old GTI (one both Mk1 Sciroccos, the 2 Rabbit GTI's, the 8v Mk2 GTI, the two 16v Mk GTI's, and the Mk 1 16v GTI) trying to see what works, and what does not.
The main point I was trying to make was that the addition of the BRB only, does not solf the other issues with the FWD platform.
If this were intended to be a my opinion vs your opinion type discussion, then it doesn't belong here, but if it is for relaying experiences and data, then so be it.
I have driven BRB cars (Mk1 Scirocco, 2.0 16v, quaife, 475lb springs front, 650 lbd springs rear, OE front bar and no front bar, and Koni's custom valved to handle the particular spring rates). It did make the car faster that the previous setup (400lb springs and BFB, 800lb rear springs with dinky little rear bar (17mm If I remember correctally), proper valved Koni's. It was significantly slowers (amonghts three good drivers). Swapping bars around no matter which springs did not help the situation. The car just stuck better with the BFB and High compression and rebound on the rear koni's. That set up worked well for the Solo 2 and Solo 1 events the car owner has run.
I am not preaching that there is only one way to do things, but that you must look at the alternatives before preaching one way or the other.
Peace,
Kevin
PS: It's always fun to set FTD in a GS car in the rain against the likes of former national champions in SP, Prep, and Mod cars...
Woohoo!!!!


Modified by bluevr6 at 11:45 PM 4-27-2004
 

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Re: BFB debate (SRSVW)

Quote, originally posted by SRSVW »
I use an ITA Golf and with a good driver it wins Street prepared and usually beats all other Prepared and some modified cars and I can assure you that it doesnt have any front bar!!

Care to share the set up with us?
 

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Discussion Starter · #14 ·
Re: BFB debate (JBrian)

I am not Dick Shine (Hi Dick
), but i will share my past setups:
98 GTI VR6 (GS) Autotech solid BFB, Koni's revalved at Koni NA's race shops to give an effective spring rate using OEM springs of 600lb/in2/sec with stock springs at 1/2 stiffest rebound setting and 1/4 stiffest compression setting and an effective spring rate in the rear using OEM springs of 1100 lbs/in2/sec at softest rebound setting and 1300 lbs/in2/sec at the stiffest setting. Very stiff for a daily driver.
This car was sold to buy baby hauler (1994 Audi S4) and new owner intends to go a different route with car (StreetTouring).
84 x-1/9 (DSP). Adco FSB (27mm) mounted via threaded rods to the strut spring perchs, 400 lbs/in2 up front and 550 lbs/in2 in rear using GC's custom valved struts.
(I ain't about to dig through 2 decades of paperwork for the info on the other cars right now).
Just thought I would through anpther peice of me on the fire....
--Kevin
 

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Discussion Starter · #15 ·
Re: BFB debate (Gazornan)

Quote, originally posted by Gazornan »
I don't know what got this thread started, maybe Kevin Bluevr6 is just stirring the pot.

Seems like with so many other discusison going on where poeple are jumping in with the you gotta use this, or you gotta use that, that the BFB / BRB deserved it's own discussion.
It is also currently going on over on the yahoo vwautox discussion list at the same time
As far as stirring the pot, "need garlic"

--Kevin
 

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Discussion Starter · #16 ·
Re: BFB debate (John A)

Quote, originally posted by John A »
i've done the simulations, I've done the calculations,

Are simulations and calculations am appropriate substitute for on couse data acusition?
Not triing to flame, just wondering how the data transferred?
Peace,
Kevin
 

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Re: BFB debate (bluevr6)

Quote, originally posted by bluevr6 »

The main point I was trying to make was that the addition of the BRB only, does not solf the other issues with the FWD platform.

are people recommending JUST a huge rear bar and removing the stock front bar without spring changes? the rear bar would help, but i wouldn't remove the front bar without serious spring re-config.
Quote »
I have driven BRB cars (Mk1 Scirocco, 2.0 16v, quaife, 475lb springs front, 650 lbd springs rear, OE front bar and no front bar, and Koni's custom valved to handle the particular spring rates).

just as a note. most BRB setups are made up the following: big rear bar, stiffer springs in the front than the rear, and little to no front bar. what you tested isn't very typical at all -- those are the same rates that most BFB setups run.
 

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Re: BFB debate (bluevr6)

Quote, originally posted by bluevr6 »

Are simulations and calculations am appropriate substitute for on couse data acusition?
Not triing to flame, just wondering how the data transferred?
Peace,
Kevin

no, but no amount of driver skill can make up for bad physics. lots of the things i've done relate to the amount of lowering, calculating roll centers, and figuring out roll couple distribution. if one setup can get me better physics to start (i.e. car will roll less, more front tire is kept to the ground) then to me i'd take that over a setup that's bad on paper and likely worse in practice. the software to do this stuff isn't cheap or easy, but it's accurate.
i take things that i've worked out in advance and use those figures to tune the car at the events. so far i think the results have been positive.
 

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Discussion Starter · #19 ·
Re: BFB debate (John A)

Quote, originally posted by John A »
are people recommending JUST a huge rear bar and removing the stock front bar without spring changes? the rear bar would help, but i wouldn't remove the front bar without serious spring re-config.

Yes, that is what I am seeing....

Quote, originally posted by John A »
just as a note. most BRB setups are made up the following: big rear bar, stiffer springs in the front than the rear, and little to no front bar. what you tested isn't very typical at all -- those are the same rates that most BFB setups run.

True, we also tried some higer spring rates (like 600, 700, 800, and back to 750 in the front with the rears dropped to (foggy memory here) like 400 or 500.)
Didn't make a hug difference. Our consensus was that the car was tritchy at constant loads on long sweepers, and the only improvement was at turn-in. Not enough of an improvement to make it work for us.
How do you guys get the twitchieness out of the front end, to keep the car from feeling like it is going in seven directions at one time?
Peace,
Kevin
 

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Discussion Starter · #20 ·
Re: BFB debate (John A)

Quote, originally posted by John A »

no, but no amount of driver skill can make up for bad physics. lots of the things i've done relate to the amount of lowering, calculating roll centers, and figuring out roll couple distribution. if one setup can get me better physics to start (i.e. car will roll less, more front tire is kept to the ground) then to me i'd take that over a setup that's bad on paper and likely worse in practice. the software to do this stuff isn't cheap or easy, but it's accurate.
i take things that i've worked out in advance and use those figures to tune the car at the events. so far i think the results have been positive.

Good to know. If you are interested (and I can get my onld data sheets off my (2 generations ago) computer, would you be interested in a sway of data?
Now that i am devenoping the Fiat, I am not sure how useful it will be, but I like having all those dta poings stored away in case i evenr need them.
BTW: Any tips on setting up a STS class VAG AWD car which will later a SM AWD car?
Peace,
Kevin
 
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