# Brake Boosting



## BLK225TT (Oct 25, 2009)

So i like to have a little fun in the car and do a little racing. I have the stage 2 revo set up full 42dd exhaust and its pretty quick, but if i could brake boost it would make all the difference! Then those other cars wouldnt pull that car length on me till that K04 spools! When ever i hold the brake in for like 3 seconds while on the gas, the car kills power to the motor! How do we get around this!?


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## Doooglasss (Aug 28, 2009)

Do you drive an automatic?

If not, rev to 6k, drop the clutch in and enjoy.


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## Spinks (Jan 4, 2010)

Obviously there's something in the ecu not allowing you to do it. Look at your throttle pulley, if you have more then one/more than one throttle body then you have traction control. Thank out the throttle cable that doesn't go to your gas pedal and try it then. Also I don't know if you have drive by wire or not, but if you do, the throttle cables wont go to the gas pedal at all, and you'll have to figure out which one is traction control and which one isn't, if the problem lyes with traction control at all...


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## surfinsk8r (Feb 8, 2010)

DougLoBue said:


> Do you drive an automatic?
> 
> If not, rev to 6k, drop the clutch in and enjoy.


How do you do that with quattro?


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## mbaron (Aug 21, 2008)

> How do you do that with quattro?


With a giant smile on your face. 

I don't know how quattro would limit your ability to launch the car like that, it really makes it easier and reduces tire slippage.


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## surfinsk8r (Feb 8, 2010)

mbaron said:


> With a giant smile on your face.
> 
> I don't know how quattro would limit your ability to launch the car like that, it really makes it easier and reduces tire slippage.


I guess I was always told not to drop the clutch with an AWD car because it can bend the axle, so I've always limited my launches to maybe 3-4k the most.

So do you guys just raise it to 6k with the clutch depressed then let out the clutch?


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## Doooglasss (Aug 28, 2009)

how else do you expect to be an E46 M3 off the line???

You have more of a chance of snapping an axle on launch with a FWD car, at least our haldex system distributes the power to all four wheels. The only thing you will be wearing down is your clutch life.

Also to whoever commented above our cars don't have any cables going to the throttle body - this is a DBW car. If you have a nice little ESP button on your dash, which 90% of TT's do, then you have traction control. If you don't then you're lucky like me and managed to get a very early 2001 225.

IF you do have ESP I believe you can have this killed by a tuner on a BT tune, however, 225's don't come as autotmatics so that question was kind of rhetorical before. You're brake pedal should have nothing to do with your launch and the only reason I can see to use the brake & gas at the same time is to left foot brake in an AutoX or track setting.


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## surfinsk8r (Feb 8, 2010)

DougLoBue said:


> You're brake pedal should have nothing to do with your launch and the only reason I can see to use the brake & gas at the same time is to left foot brake in an AutoX or track setting.


Never heard of brake boosting? Its to eliminate turbo lag off the line in a drag race, essentially.


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## surfinsk8r (Feb 8, 2010)

DougLoBue said:


> The only thing you will be wearing down is your clutch life.


So what is the proper way to launch an AWD TT?
I want to minimize clutch wear, I can't launch for 500 miles anyways I just put a st3 clutch in yesterday.


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## mbaron (Aug 21, 2008)

At the AutoX I usually launch at about 4700, I very quickly let off the clutch because I never liked just popping it, then the gas pedal goes to the floor. Then be ready to go to second gear.

I never touch the brakes during a launch.


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## surfinsk8r (Feb 8, 2010)

mbaron said:


> At the AutoX I usually launch at about 4700, I very quickly let off the clutch because I never liked just popping it, then the gas pedal goes to the floor. Then be ready to go to second gear.
> 
> I never touch the brakes during a launch.


So:
Clutch In
First Gear
Raise RPM to 4700rpm
Let out clutch
Floor it

Correct?


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## wrparrish (Nov 13, 2008)

I think alot depends on what sort of abuse your willing to put into your drivetrain.

I drop the clutch at redline, give it a second to catch its breath, and grab second.

Ive got a Stage III endurance series southbend clutch, and a lw flywheel though. Its ****ing glorious on the launch. :beer:


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## mbaron (Aug 21, 2008)

Very true, with your upgraded clutch, you should be able to go higher than 4700


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## surfinsk8r (Feb 8, 2010)

wrparrish said:


> I think alot depends on what sort of abuse your willing to put into your drivetrain.
> 
> I drop the clutch at redline, give it a second to catch its breath, and grab second.
> 
> Ive got a Stage III endurance series southbend clutch, and a lw flywheel though. Its ****ing glorious on the launch. :beer:


I have the Clutchmasters Stage 3 clutch, and a steel lightweight flywheel (13lb vs 22lb, chatters).
So I can do the same thing? I will be honest I have very little experience with launching an AWD car, and just want to do it right before I f*** things up.


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## Doooglasss (Aug 28, 2009)

Honestly any time that the motor rev's are going faster than the drivetrain is traveling than you're going to have clutch wear. You might as well enjoy every launch and do them less frequently. The only real way to "do it right" is to learn on your own. I remember spending early mornings (3-5am) on the road stopped, launch the car hard, stop, do it again - about 20 times a night until I got it down. After that I abused the hell out of it and had completely destroyed my clutch at 68k.

I'd have to agree with Mbarron I don't exactly pop the clutch but I quickly engage it then be ready to slam the car into second gear shortly thereafter. 

I just installed a 13 lbs. flywheel by Spec - is that what you have? How is the chattering and when does it occur? Just with the clutch depressed at a stop right? I ask because I won't be able to drive the car for another 2-3 weeks at least...

FYI: Stock dual mass 240mm flywheel is 39 lbs.


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## surfinsk8r (Feb 8, 2010)

DougLoBue said:


> Honestly any time that the motor rev's are going faster than the drivetrain is traveling than you're going to have clutch wear. You might as well enjoy every launch and do them less frequently. The only real way to "do it right" is to learn on your own. I remember spending early mornings (3-5am) on the road stopped, launch the car hard, stop, do it again - about 20 times a night until I got it down. After that I abused the hell out of it and had completely destroyed my clutch at 68k.
> 
> I'd have to agree with Mbarron I don't exactly pop the clutch but I quickly engage it then be ready to slam the car into second gear shortly thereafter.
> 
> ...


Oh wow - didn't realize it was 39 lbs stock.
I just went with the clutch/flywheel package by clutchmasters, the fx300, as recommended by my vw/audi specific performance shop. Its a steel lightweight flywheel, I was told 13 lbs.

Chatter is just when the clutch is NOT depressed, if you depress it than its silent.
I've also noticed the chatter is inconsistent, it does not always chatter, but when it does its not that bad and its the same volume (db) every time and its not that loud at all.

I have yet to really push my car since I got the clutch in, because apparently my clutch has 'significant break-in required' and my tuner recommended really taking it easy on shifting and overall driving.

I think I may have a problem with my boost controller as well, and my n75.
With my boost controller, if I set the boost to what I used to have it at about a month ago, 22 psi, it boosts to it real fast than blows off to around 8-9psi.
However, if I use my low boost setting, setting B, it will boost to 15/16 psi no problem and hold it.
Its almost like my setting A doesn't work correctly.
And I run the boost controller as a standalone, because last time I plugged the n75 in I would boost to 25 psi which is way too much.


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## wrparrish (Nov 13, 2008)

surfinsk8r said:


> I just went with the clutch/flywheel package by clutchmasters, the fx300,.


One thing to keep in mind, is that when you take the time to purchase parts that are designed and intended for a specific use, you are then able to match your driving habits to that behavior. 

The parts you have selected are designed to see abuse, far beyond what a stock clutch should, and then operate comfortably within that level. I understand your hesitance, and thats normal, but keep in mind the equipment youve given yourself, and its intended purpose. 

So, to say it simply, launch the **** out of it and have a good time.

Now also for what its worth, alot of guys have a preferrence otherwise, but i completely snap my clutch pedal out when im launching. Its the most harsh way to do it, but i bought the components i did for a reason. :beer:


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## bvgoosedd (Mar 5, 2009)

I a ? I have a WOT BOX set at 5200. Launch is f++king nuts. Quikly let go too like the others. I have st3 cluthnet. I didnt get the fly wheel tho. Do u guys ever have a problem getting into second. Like my car it wont let me go to secobd if my rpms are past 5500 only in first to sevond. no grinding either. Is that cus I didnt do the flywheel or is it my trans?


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## Doooglasss (Aug 28, 2009)

Sunfinsk8r:

a lightweight flywheel will make your car rev faster and also drop RPM's faster. So you should enter boost faster and get out of it faster as well when letting off the pedal.

Also if you're using a mechanical boost gauge than you might not be getting accurate readings. You should run a vagcom log with your N75 acting as your boost controller and see what you get as a result.


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## surfinsk8r (Feb 8, 2010)

DougLoBue said:


> Sunfinsk8r:
> 
> a lightweight flywheel will make your car rev faster and also drop RPM's faster. So you should enter boost faster and get out of it faster as well when letting off the pedal.
> 
> Also if you're using a mechanical boost gauge than you might not be getting accurate readings. You should run a vagcom log with your N75 acting as your boost controller and see what you get as a result.


I had the problem right before I got the clutch/flywheel, so I don't think they're related.

I'm using the AEM TruBoost Boost Controller and Boost Gauge. Its hooked up to a T in the FPR line, and it is hooked up correctly. The gauge is digital and I get pretty exact/instantaneous readings.

I am thinking of hooking up my N75, it at least holds boost but it boosts too high, to 25psi.

I may purchase a VAGCOM before I return to school friday.


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## bvgoosedd (Mar 5, 2009)

is that refering to me. so i should get a flywheel?? or should i just redo the clutch and flywheel? which flywheel do you guys recommened. i know the steel single mass flywheel, but is there a spefic company? 
Thanks by the way


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## surfinsk8r (Feb 8, 2010)

bvgoosedd said:


> is that refering to me. so i should get a flywheel?? or should i just redo the clutch and flywheel? which flywheel do you guys recommened. i know the steel single mass flywheel, but is there a spefic company?
> Thanks by the way


Is what referring to you?
And I don't know if your 5500rpm problem is flywheel related.


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## Doooglasss (Aug 28, 2009)

A flywheel will not change your cars first to second shift. Maybe check your shifter cable alignment and refine your shifting habits.


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## bvgoosedd (Mar 5, 2009)

Well as far as shifting habits it doesn't matter if i try to get on it or if i rev it out slowly and it i would say it does it like 80% of the time. it's not like i don't know how to drive my car. i've had it for 5 years. i do have a gt30 under the hood as well. but this only happened after i changed the clutch. never had a problem with my trans. and still it doen't grind it's like when you try to shift to first and the car doesn't let you. it like forces it so you can get into that gear. with the WOT box i can do the no lift shift and it'll still do it. or i can drive normal and it'll do it. only first to second do. i have gotton the shift bushings and flushed the trans i got the dog bone redone just in case. i don't know what else to try. that's why iam asking for your ideas. i don't even know were to bring it to get looked at. when i brought it to the shop it didn't do it. it shifted fine. i don't wanna do the intake manifold and w/m untill i figure this out. can someone tell me were to look?


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## Doooglasss (Aug 28, 2009)

Link me to the clutchnet disc that you have?

I just went through a clutchnet install on my car. I'm not sure you did the install correctly. Most clutchnet yellow/red (stage 2/3) clutches require a single mass flywheel because they are mounted inverted to a normal disc.

A normal disc has it's center hub (where the springs are) facing the pressure plate. The clutchnet discs face the flywheel - which is why they advertise they require a ligthweight flywheel on their website because the dual mass flywheel doesn't have a recess for the sprung hub to fit in. See the below pictures for what I'm talking about:

My fingers are holding the clutchnet huge hub...



stock DMF doesn't have a place for that...



SMF has a space for the hub...



If you install the clutch with the hub facing the pressure plate there isn't enough space for the slave cylinder to fully depress the pressure plate thus it won't fully release the clutch because it will hit the giant clutchnet hub. This is why they have you face it towards the flywheel.


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## bvgoosedd (Mar 5, 2009)

That is what I was looking for. I honestly didnt do the install. Do u think it would be worth it to change the whole thing or just do a flywheel. Can a shop look at that for me or should I just replace everything.


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## Doooglasss (Aug 28, 2009)

Honestly I have zero trust in all shops and other people dealing with my car. If it's not done by me then it's not done right.

If you trust your shop then just purchase a flywheel from Spec SV81S like pictured above and give them very detailed directions on how the clutch is not installed traditionally. If I were you I'd do the job yourself- it's not that hard...


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