well a couple weeks back i raced a 00 WS6 M6 and when i launch with it in [D] i power brake and then when i launch i just keep spinning on my Goodyear F1 275/40/17 until i red line. when i red line it shifts into second and then my rpms drop to like ~3000.

he pulled on me since i fell out of the powerband....

i wanted to try to do it in D and feather it out but when i let off it just shifts.... i hear people say it isnt good to throw it down into 1 and then shift your car manually w/ an A4 (4L60E). why is it bad? is there another way i should try launching in my car?... an obvious solution is to buy new tires (DRs) but i dont feel like wasting money on it right now...

couldnt decide if this should be in LS1/LS6, General, Drivtrain, or Drag Racing tech...

-Dakota

 

i could use a little help....

 

There's nothing bad about manually shifting the car unless you are doing it constantly. Why do you think they put those selections there in the first place?

About launching, it isn't going to make a difference from [D] and D. In WOT you can't hit 4th in either. In a stock car you can't really powerbrake the car and have it do much good. The most you can get to is maybe 1800-2000 and your RPM hits that point so quickly it really isn't helping much. Usually when people launch and power brake it's because they have a 3400 stall or something, so they can hold the brake and rev to 3000 safely without the car moving.

 

I've used both techniques - stalling it up before launching, and launching off idle. I can't say that 1 way consistantly works better than another. It really depends on the day and the conditions. Ideally, I think it's better launching off idle, because then IMO the engine has a second to build some momentum, and it flashes the converter a little higher. I find that by stalling it up ("power braking" as you're calling it) then the car feels like it bogs worse off the line. BUT, sometimes that seems to work better if by flashing it off the line, you're breaking loose.

As far as manually shifting ... well, just about all automatics have had GEAR SHIFTERS since the dawn of time! PLENTY of people manually shift their autos, and have no problems. If the tranny craps out, I think it's just because the tranny was bound to crap out . Ideally, if you have your shift points setup right (whether it's stock, or adjusted using a programmer) then leaving it in Drive (3rd) is usually the best. The shifts will be consistant, and always at the same speed/RPM. However, sometimes if the shift points aren't quite in the right place, then manually shifting (to hold onto a gear longer) IS beneficial. Argue all you want people, but I've got enough time slips from Test & Tune nights, and I know that on back-to-back runs, I've improved my times by as much as ~2 tenths and ~1 - 2 mph by manually shifting .

IMO though, a shift kit and tranny cooler would be a good (relatively inexpensive) investment to help your tranny last as long as possible in stock form . Shift kits firm up the shifts by reducing the amount of HEAT GENERATING SLIP ... and for most mechanical components (engines, diffs, and trannies) heat KILLS!!!

 

cani just let my motor bounce off the rev limiter a few times till i am closer to 45 mph then shift it into second? is it bad to let the motor bounce off the rev limiter which means i have to just feather the throttle till my mph get higher

 

Ttt

 

If you're talking about holding each gear manually, and waiting to shift until the motor hits the rev limiter?? NO, don't do that!!!

The stock 4L60E is really slow to react to manual shifts, so if you want it to shift 1-2 at ~6000 RPM, you've gotta move the shifter around ~5500 RPM if you're at WOT. 2-3 doesn't have quite as much delay, but still shift a couple hundred RPM before the point where you want it to shift. If you are too late, you'll know when you hit the rev limiter and it bounces off it before the shift!

 

ya ive had that happen a few times and loose races that way but its all good

 

well not really, lets see if i can explain this...

when i launch, since i dont have sticky tires, my car just spins in 1st gear till the red line; then is shifts into 2nd and i finally grab traction. When i get traction in second gear, I am at 3k rpms and i have come to believe this:

1st gear on my car will go to ~45 mph; when i spin to 6k my car really isnt moving at 45mph so when it shifts into second, i will be going less than 45 mph which will make my rpms fall ~3k and drop me out of the power band....

the way i can only think of is to put it in 1st gear and feather it out or leave it in 1st and let it bouce of the rev limiter till i get traction... i figure it prolly isnt good to let it bounce off but then again, i wont know till i ask. how exctly do you feather it out when you are in first gear... just trying to get a few tips before i race a guy....

Thanks,
Dakota

 

The first three times I can my car at the track I launched foot from brake to gas.
14.1 then 14.2

Power braked it and luanched like a ticked off bat out of hell! Car spun but hook close to second. Hit second and almost threw the back end of the car into the wall when it hit a coolant patch that the track missed when the cleaned it. Car hooked just before I ws going to sut it down... ran a 14.1. If the car would not have got nead sideways I know it would have done a lot better... just my opinion here.

 

I always leave my car in D, although I have manually shifted it before without much difference. The best thing you could do for improved launches is obviously DR's, but you could also get a Stall and eliminate your problems. Stall+Dr's or Stall+Sticky Street Tire, will obviously improve launches and eliminate the "Dead Zone" in A4's. I would check out FuddleRacing.com if your in the market for a stall, a lot of people have had great success with them, and they are cheap compared to Yank, Vig Etc.

 

i am not really down with high stalled torque converters... i just think they are annoying for a weekend driver....

i am saving up some money after i install my SFC to get some nitto 555r on some 17" x 9" 10 spokes

still no one has answered my question....

 

Leave it in 3 and roll into the throttle of idle...Its a rhythm...Don't flat out floor it, just roll your foot into it to the floor and let it shift itself. If you are constantly bouncing off the rev limiter you may have a transmission problem. Get some DRs on 16" wheels. The 17s will be ok, but the added sidewall of the 16 will give you alot more traction. In drag racing your "front to back" tire contact patch means more than the "side to side"..As far as going with a converter and it being "annoying" I would bet that youd have a hard time telling that I have a 3600 stall converter in the car. You can also have someone program your shift point rpms to be consistent.

I'm able to leave off idle and floor it with the M/T DRs 255 50 16s letting the trans shift itself as programmed by PCMForless...

First you need DRs...See where your trans shifts itself when you are not spinning. If your hooking up and you still hit the rev limiter then you may have a slipping trans. Good luck...

--Alan

 

I hear your frustration, but DON'T INTENTIONALLY hit the rev limiter and hold it there 'til you get traction!!!!

You're going to have to learn to come on to it nice and easy, then roll onto the trottle once you're moving. Now I know that if you're too "easy" on it, the tranny will shift into 2nd before you get your foot to the floor, and that's when you feel the need to manually shift. So be it, IMO, for the few times that you're racing and want a "perfect launch", then hold 1st gear until you can get it to hook. But like I said, move the shifter up to 2nd around ~5500 - 5600 RPM so you DON'T hit the rev limiter. Not that it's going to "kill" your engine, but try to avoid it (it won't help your times at all, I can tell you that).

BUT, you really should practise launching with the shifter in 3rd/D, and find a "sweet spot" for how much throttle you can give it without breaking loose like crazy. Until you get good TIRES on your car though (even good street tires) then you may never really find what you're looking for. Put sticky tires on, make the car hook, THEN you'll be wanting that stall converter you don't think you need right now.