[jboyorak]

What technique are people using to launch their auto?

I am having a difficult time finding one that is consistent and aggressive enough.

I brake boost to about 2-2500(whatever it lets me do) and let of on the brake while slowing pushing to full throttle. The launches are slow for the most part. Pulling 1.9 60' usually. With the low end torque these have and awd, I should be be able to pump out 1.7 all day long.

[S-P335xi]

try lunching at 3000

[Andrewe92]

im actually curious about this too, with xdrive and auto it's kinda hard to get a good launch... to be honest i cant even brake boost a launch

[deeLow]

Originally Posted by Andrewe92

im actually curious about this too, with xdrive and auto it's kinda hard to get a good launch... to be honest i cant even brake boost a launch

You're A: not holding the brake hard enough and B: not giving enough gas.

It is tricky, and hard on the car

[jboyorak]

Brake boosting the most rpm I get is about 2500. Full throttle/half throttle doesn't seen to matter.

Just tried again this weekend. I see there are people with steptronic pulling some good 60', so I am only to assume there is something wrong with my setup or technique?

[SaviorXi]

I run 1.7-1.8 with consistent regularity.


The procedure I use is-
1) Hold DTC button in until DSC and DTC are turned off. (yellow warning symbol on dash)
2) Shift into sport mode and manually shift into 1st gear.
3) Hold in brake all the way.
4) 4 seconds before green light floor the car.
5) When green, keep car floored and let go of brake.
6) let car shift automatically from 1st to 2nd and then manually shift at 6000 RPMs thereafter.

If results are not good you should check-
1) Tire condition/make/tread/pressure
2) Car condition and maintenance
3) Your cars Tune and settings
4) your body weight
5) Track conditions including what equipment track uses, regular maintenance and calibration.
6) Weather, temperature, altitude

Best of luck

[Nonecure]

Originally Posted by SaviorXi

I run 1.7-1.8 with consistent regularity.


The procedure I use is-
1) Hold DTC button in until DSC and DTC are turned off. (yellow warning symbol on dash)
2) Shift into sport mode and manually shift into 1st gear.
3) Hold in brake all the way.
4) 4 seconds before green light floor the car.
5) When green, keep car floored and let go of brake.

If results are not good you should check-
1) Tire condition/make/tread/pressure
2) Car condition and maintenance
3) Your cars Tune and settings
4) your body weight
5) Track conditions including what equipment track uses, regular maintenance and calibration.
6) Weather, temperature, altitude

Best of luck

Nice write up!

I have not had my car at the track yet, plan to though. How do you know when you have about 4 seconds? My memory from years ago was the light tree moves really fast.

Do you stay above kick-down? Do you let the auto shift 1-2, but then shift after that at a lower rpm?

[SaviorXi]

I try to get to the line and double yellow light before the other car I am racing since I have xdrive and they are usually burning tires it gives me more than enough time. As they are inching up to the line and get single yellow that is when I start brake boost. I let the car shift from 1-2 and the I manually shift after that at 6000 RPMs. Hope that helps.

[M.a.r.k.u.s]

the longer you hold rpm's the harder it is on your tranny. Track is the only place I brake boost and I usually just floor it about 2 seconds before i let off the brake (about 3000 rpm) and consistently cut 1.7's. I have launched the car at 5000 rpm and broke all four tires loose but it didn't produce a better 60ft time and it is harder on the car.

I have noticed that a downpipe helps quite a bit when launching the car due to the throttle response being much better than with stock dp.

[Southjersey128]

Originally Posted by SaviorXi

I run 1.7-1.8 with consistent regularity.

4) your body weight

[v1nc86]

I brake boost at 2500-2750 RPM and cut a 1.7x 60 foot every time.

[X.X.I.V]

Originally Posted by v1nc86

I brake boost at 2500-2750 RPM and cut a 1.7x 60 foot every time.

Nice
Just tried this yesterday
I'm FBO just 93oct
And I can't get the tires to break loose no matter how many times I've tried
It's a testament to how grippy my Conti DWS's are I guess

[jboyorak]

A little late getting back to this. Here is some more technical info.

It appears the car isn't building boost off the line. I am using flash software, tunerpro, and bavarian technic to log.

It appears the car wants to build boost at first. Boost target initially goes to roughly 8-9 psi, then abruptly drops off to nothing and the dme closes the throttle. As soon as I start rolling target boost then goes up to normal.

I'd assume this is in the factory tuning to avoid doing just what I want to do. Is there a way to tune this out with a flash or do I need to use a piggyback to achieve what I want?