View Full Version : Better launch...
lswing
June 16th, 2013, 02:38
Ok, I bring this up every few months. Anybody been doing launches while building boost with left foot braking?
I keep trying to weigh the pros (faster, fun) and cons (wear on tc, trans, driveline).
Anyone ever break anything launching?
I totally would have beat that Carrera S I keep telling myself...:addict::revs:
10SecS4
June 16th, 2013, 03:05
Yes, I have. After a couple hundred or so launches, I snapped my transmission's input shaft clean in half.
I would not recommend it unless you want to spend thousands in labor and/or parts.
lswing
June 16th, 2013, 03:11
Sounds about right, I'm thinking every month or two, but who knows when a part can pop...
makaveli42
June 16th, 2013, 21:46
I try it once and awhile. Seems I can always do it just randomly at a stop light but never get it to build boost at the track! I have viper tune with left foot braking too. Fun as hell when it actually works but car launches like a dog turd when it doesn't. Just flooring it with no building boast is sloooow. I know the RS6 isn't a 0-60 car but I'd love to figure out how to make it launch better!!
BigD2500HD
June 16th, 2013, 22:35
Anyone installed a high stall speed converter? Say, maybe 2400 rpm stall speed?
lswing
June 17th, 2013, 02:27
Too much spinning under dailing driving conditions, raising fluid temps. Thought about raising the speed when my tc was rebuilt, stayed stock. There would be too much delay, although you could drag it good.
More of the point is spinning up the turbos, dealing with stock stall speed. Rev, rev, rev go!, sounds like the trick to bringing up boost while dealing with stall...
Think I got this right...
v8a6
June 18th, 2013, 17:21
Yes, I have. After a couple hundred or so launches, I snapped my transmission's input shaft clean in half.
I would not recommend it unless you want to spend thousands in labor and/or parts.
cost for repair of input shaft / couple hundred launches = around $20 per launch ? Seems like it might be worth it :)
Other_Erik
June 18th, 2013, 17:31
cost for repair of input shaft / couple hundred launches = around $20 per launch ? Seems like it might be worth it :)
Really, it's $0/launch, until it breaks. Then there's a single really expensive launch. Kinda like skydiving without a parachute, it's not the fall that kills you, but the sudden stop at the bottom...
Other_Erik
v8a6
June 18th, 2013, 17:49
Really, it's $0/launch, until it breaks. Then there's a single really expensive launch. Kinda like skydiving without a parachute, it's not the fall that kills you, but the sudden stop at the bottom...
Other_Erik
ahahHAHAHAHAha .... you're right :) It's the launch that costs four thousand dollars LOL.
I had a ceramic clutch installed on my 4.2 that is putting down almost 300 lb/ft to the wheels. I went through a period when I was dropping the clutch, spinning the tires, and launching like crazy. It was a blast until my car suddenly started making a huge banging sound. I thought it was something major, and felt really bad and stupid for abusing the car. Turns out, it was a bad driveshaft. I picked up a used one and was back on the road for under $300.
So, you think I would have learned my lesson. But, I soon forgot about the bad feelings that I had, and started launching again. Not as often, but now and again. I am still awaiting my $4000 launch
Kgnast
August 30th, 2013, 02:33
I don't know if it's actually brake boosting as I have not logged the car from a launch, but I do get all 4 wheels going at about 2700 rpm when I let the brakes go. Gas, Gas, Gas and hold, RPMS come up and as soon as they stop moving upwards, off I go. If the traction control is on, it blinks all the way through 1st. If its off, all 4 tires rip the pavement. I am pretty sure at the rate I am going, I'll be ponying up for the 01E before long.
Ok, I bring this up every few months. Anybody been doing launches while building boost with left foot braking?
I keep trying to weigh the pros (faster, fun) and cons (wear on tc, trans, driveline).
Anyone ever break anything launching?
I totally would have beat that Carrera S I keep telling myself...:addict::revs:
Kgnast
August 30th, 2013, 02:35
No need, I believe they call it, Duck Rat Foot Technique or something like that.... Gas once, gas twice, gas a 3rd time and hold, RPMS will climb up to 2700 or so rpm, then dump the brakes. When I say gas, I mean brake stand it, and hit the gas pedal like you were revving it up, rev once, rev twice, rev and hold..... on...... hahah.
Anyone installed a high stall speed converter? Say, maybe 2400 rpm stall speed?
lswing
August 30th, 2013, 06:21
I am pretty sure at the rate I am going, I'll be ponying up for the 01E before long.
Yes you will...it's only a matter of time. Dropping $7k every year or two just to launch this beast seems a bit high. If my back was better and a manual was in the future that would be nice. Thinking another high power car for that fun, Corvette or Cts-V maybe...rs6 does a lot, but limits are there for sure.
ttboost
August 30th, 2013, 12:06
I don't know if it's actually brake boosting as I have not logged the car from a launch, but I do get all 4 wheels going at about 2700 rpm when I let the brakes go. Gas, Gas, Gas and hold, RPMS come up and as soon as they stop moving upwards, off I go. If the traction control is on, it blinks all the way through 1st. If its off, all 4 tires rip the pavement. I am pretty sure at the rate I am going, I'll be ponying up for the 01E before long.
Take a ride back up some time and go for a ride in one...you will be convinced.....
G2
August 31st, 2013, 19:48
If the traction control is on, it blinks all the way through 1st. If its off, all 4 tires rip the pavement.
Curious what tires? And conditions- dry, wet, cold, hot?
Styhl
May 16th, 2014, 15:20
Iswing, did you figure out a good launch technique? I'm thinking of taking mine to the drag strip here, they have a 'true street' bracket I'm sure is full of zo6's and mustangs. I was wondering if our quattro was enough to keep me in.I cloned my car into forza 4 on my Xbox but that's still not gonna tell me when I snap my input shaft... I was thinking of a 2k rpm brake release since the torque curve lines up there, thoughts?
4everRS
May 16th, 2014, 23:54
If your holding the brake, the ecu won't let you build boost.
You either need to fool the ecu to allow boosting while holding the brake(duck foot rat), or get it tuned out. Most tuners will call it left foot braking.
Styhl
May 17th, 2014, 00:52
Ya but peak torque is still at 2k rpm, right isn't that a good point to launch from?
4everRS
May 17th, 2014, 01:26
If your car is stock, then ya, torque builds strong at 2k and above. If tuned, torque will continue climbing to about 4500ish.
It doesn't negate the fact that you can't get torque without boost. And holding your brake will not allow boost
Styhl
May 17th, 2014, 01:39
Idk if my Revo tune defeats the no left foot guess I'll just play around.
4everRS
May 17th, 2014, 02:00
It has to be requested. Not a standard tune option, as speed limiter disable would be.
Styhl
May 17th, 2014, 03:30
Hmm need to get my tune scanned then. Thanks for your help.
DHall1
May 17th, 2014, 04:27
did you fix the oxygen sensors yet.
Styhl
May 17th, 2014, 05:02
No it turns on and off Ive not got vagcom yet. It turned off after the alternator change and didn't come on for a couple days til it got really hot outside again.
I noticed that it takes a moment for the ECU to reduce the torque request during left foot braking. Haven't tried a hard launch, but if correctly timed, it might allow a brief window to load the engine....
kilian tuning
May 18th, 2014, 17:49
can the 517 box handle launches while building boost with left foot braking?
lswing
May 20th, 2014, 00:09
I never launched the car since I've found other ways to break the trans....but, I did try building boost, and it sure seems like it WOULD launch.
Left foot on brake, rev once, rev twice, rev thrice....revs pop up above 2,000 and you can hear turbos spool, car lurches around in place. My guessing is a nice drop off the brakes and punching of right foot would achieve great results.
If I ever try this I'll be doing it on wet pavement with my winter tires, so I know it will spin.
A slow launch easing into the gas gets me a 4.3-4.5 0-60, that's not too shabby!
I haven't tried it and the car is sitting at a car lot on consignment to be sold. But I did try the launch control in an s7 over the weekend, now that is how it is supposed to work.
makaveli42
May 20th, 2014, 23:25
I haven't tried it and the car is sitting at a car lot on consignment to be sold. But I did try the launch control in an s7 over the weekend, now that is how it is supposed to work.
what side of Indy is the carlot on?
what side of Indy is the carlot on?
it was in Melbourne fla, where my daughter goes to school.