what rpm should i launch .......i have a built b18 turbo......make 350hp.....myfriend told me i should launch at 3000rpm...but i try and i broke the tranny.....help

 

broke the trans or a axle?

Cause i already broke a axle.. popping the clutch.

 

I was making 392hp on 24.5x8x15" mickey thompson slicks and I had to launch at 6000rpm with a 2 step. I had a stock b16 tranny with quaife lsd and older stage 5 dss axles. Mine held through several events and is still in the car and the car is now going to be making a lot more power.

If your tranny broke at 3000, then it may have already been at its breaking point and that put it over the edge. "The straw that broke the camels back" so to speak.

What broke?

 

I launch with the 2 step set between 5500rpm and 6500rpm, on M&H 24.5 slicks t67 turbo. shifting at 9600rpm

 

I am going to take a guess and assume that you didnt preload, since you broke the tranny at 3k rpm.

 

stock gsr tranny....stock axles....launching at 7500 on 2 step....24.5x8x13 MT slicks
have not had a problem running 10's, no breakage for almost 3 years
PRELOAD

 

agreed, preload. Ive been lucky not to break anything when I just launch, but Ive always had a sprung disc so that helped. Im going to be using a tilton twin disc that is not sprung. So Ill be preloading now.

 

Are you running stock mounts? I launch 7k, 25x8.7 MH tires, and I've gone through 2 trannys in 6 passes with stock filled mounts.

 

You probably broke because you bogged hard with stock mounts? I say launch higher start at 6000rpm. The actual launch: once you are prestaged (first small light lit), start moving up slowly with the clutch barely off the floor. Once you are staged (second small light lit), pull the e-brake enough to hold the car stationary. Get the revs up and go full throttle as you smoothly release the clutch while dropping the e-brake. Holding the ebrake up while the car is trying to move forward will load your axles to reduce the shock on axles as well as other trans parts-hence the term preload. Adjust the revs depending on if you spun too hard or bogged.

What tire are you running?

 

launching at 7.5k on the 2 step cutting low 1.6's
stock axles

 

I launch at about 7k with DSS 2.9 axles and am running MT 24.5X9 slicks and I am open diff and manage to pull 1.6 60's and I don't really pre load either.

Maybe the halfshaft broke that happened to me once and I though my trans was shot.

 

what does preload mean? does it mean to get moving a bit before you fully drop the clutch?