boost controller

Re: boost controller (bercatfan)

you'll be fine. these turbos when chipped are pushing more than the 14.5 p.s.i. that this thing gives you.
http://****************.com/smile/emthup.gif

Re: boost controller (spaceman_spiff)

seems to confirm that splitsec has a new controller out....looked under the passat section, they now have one for 99-01, and 02+ http://****************.com/smile/emthup.gif
- scott

Re: boost controller (scotty_passat)

spiff:
good news!
just spoke to split-second, the "fix" is to solder in a 1M ohm resistor pot...into the blue wire (ie cut blue wire, then insert pot inline.) they ar sending them out upon request, or you can pick one up and try it yourself.
to tune, set the BCS to max and the pot to 0 ohms, this is the same as an uncut wire. slowly increase the value of the pot untill it pulls strongly all the way to redline. that is it! the pot could then be removed and a fixed resistor soldered in its place.
the guy I spoke to said that sure enough, this will tweak the clamp circuit just a bit. the throttle plate is closing because the clamp isn't quite right and the ecu is "seeing" the boost.
i'm all over this mod tonight/tomorrow, and will post the findings ASAP.
http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif

Re: boost controller (scotty_passat)

very cool! (you beat me to it -i was just about to call them, too!)
so were they pretty open about talking about how it worked? it's cool that they gave you the fix over the phone like that.

looks like i'm hitting radio (s)hack on the way home.
(if only vag-com would work...lol)

Re: boost controller (CuStOm)

well, i went and played tonight and at about 405K ohms it felt like it was fixed. surging was gone, and the 5,000 rpm dropoff seemed to dissapear. if i had a vag-com working, i could be a little more scientific about it, but i'll leave that to you, scott http://****************.com/smile/emthup.gif

(sorry to bercatfan, we kinda hijacked your topic )

Edit: i messed up on a number...)


[Modified by spaceman_spiff, 5:14 PM 2-9-2002]

Re: boost controller (CuStOm)

scott and a few other people have devoted a lot of time to researching how these bcs's work, and what's happening when they don't. originally there was a post (or maybe even a few) that pointed out how the power was dropping out after a certain rpm. go here for more info on that...
http://forums.vwvortex.com/zerothread?id=173012
now recently i got my own bcs, and after turning it all the way up and flooring it, the car was surging like a pissed off bull in 1st and 2nd, and when i got to 3rd, it would shoot up to max boost (around 15 or so psi on my mechanical gauge) pull like a train, then give out at around 3-5k rpm. when i say give out, it would feel like i let half off the gas instantly and go to about 6 or 7 psi. as scott theorized, the throttle plate was closing after the engine saw the extra power and went "holy poop!!". this seems to happen because on the newer cars, (engine codes AWW (2001.5-2002) and AWP (2002-?)) more boost was created by the bigger turbo, and gains went past what the car's stock ecu was made to handle. thus, by putting in this resistor in the feedback wire, the bcs basically not running the turbo as hard because it's bigger, and less push is needed by the bcs to make the extra power... is this making sense? i feel like i'm rambling.
anywhoo, that's it in a nutshell http://****************.com/smile/emthup.gif did it help?

Re: boost controller (spaceman_spiff)

yep, the fix works.
i added a 1 Mohm pot in series with the blue config wire, then ran some tests. first, set it to zero ohms, and ran a log of block 3. just like before, the throttle plate closed at 5000 rpm, dropping the maf flow. i then set the pot to 50K ohm, and repeated...the throttle plate now stayed at 100% all the way to a tested 6000 rpm. i had been running at 13 psi or so, now at max the boost comes on harder/faster at lower rpms....it finally works as advertised.
I've got a few graphs that i'll add later showing the maf flow difference...pretty dramatic. have to relog block 115, and repeat the dyno estimate run.
Splitsec said that the new units are designed with a 500K pot. should give lots of room for adjustment.
I'm going to add a fixed resister to mine, because the 1M pot is pretty sensitive (and bulky)
to spiff for the info. I's say its definitely a good buy now.
-Scott

Re: boost controller (scotty_passat)

mmmmmmmm.... boost plots!
i haven't tried opening it up because i didn't know what would happen, and the last thing i need is a cel (though thinking about it, i have no idea why it would...) i'll try it on my way home from work -i have a half hour drive to play with it. i should be getting my "magic little box" this week from freedom design, but i think i'll just do the resistor thing so it's not bulky.

Re: boost controller (spaceman_spiff)

yep, the box is just a 500K pot according to split-sec. would be interesting to see if it is calibrated..ie resistance coded for different engine codes.
we'll need the details of course... http://****************.com/smile/emthup.gif
-scott

Re: boost controller (Larry1.8TTU)

my car is a Passat with AUG engine....like an AWW.
"pot" (in this case ) is short for potentiometer...a variable resistor. 1M = 1 mega-ohm resistance...this means you can adjust it between 0 ohms and 1 M ohm.
they usually have 3 terminals, you connect to the middle terminal and to either one of the outer terminals, then use a multimter to set it to the resistance you want. It's like the device used on your radio for volume control.
here is a link for a picture: http://www.radioshack.com/SupportGate.asp?SupportPage=/support_supplies/doc18/18001.htm
to install, cut the blue config wire, and hook one lead to each end of the two terminals your are using on the pot. very simple to install. I soldered a set of alligator clips to it for quick testing.
I set it to zero intitally, since this is equivalent to having an uncut config wire (0 ohm = a short circuit) Note that 1 M ohms is for all practical purposes an open circuit (ie just like having the wire cut)...you now have a way to set it between "cut" and "uncut".
I verified that the throttle plate closed when set to 0 ohms, then just bumped it up a bit and re-tested, when I saw that the plate was no longer closing, I pulled it off and measured it again (was 50K ohms).
I've since added a quick-disconnect connector to the blue wire, and have replaced the pot with a fixed 47K ohm resistor, and it works great. (much smaller) I'm going to play with the value some more and see how it affects boost/MAF, I have a feeling I can get a bit more out of it without tripping the throttle plate.
There are other types of pots if you want to keep it adjustable, look for a 15-turn trimmer...they are small and are tuned using a small screwdriver. radioshack didn't have the correct one in stock so i went with the bulky type.
Pics/plots will be up tomorrow.
-Scott