help with launching my car

Tom Tom Turbo

Turbo Goes Woo Woo
Joined
Jul 10, 2002
what is going on here? With the mods in my sig I can only hold about 3 psi before the tires start breaking loose. I want to be launching around 8 or 9 psi to get an awesome 60' time. Right now the car's best with slicks is a 2.0, but that was with a set of control arms that were kinda goofy. Do I need a line lock to hold that kind of boost or just the bigger shoes in the rear?
 
Line lock is for locking front tires while doing a burn out, not launching the car. A transbrake is used to hold car at line and launch hard. :)
 
Try a trans brake. Best bang for the buck. I have 100% stock suspension, even the original shocks and arms. I get an easy 1.51 with a tranny brake. Never tried higher boost. I've gone up to only 9-10PSI launch. VERY fun! Cheap also. Don't get carried away with the He-Man, Uber-launches, the axles may brake around 10PSI. I upgraded that and the wheel studs to the next size up. Driveshaft loop is a good idea.
 
If you want to foot brake it then you will need the larger wheel cylinders from an S-10, manual tranny, non AC ( I think, just search S-10 wheel cylinders ) and get two sets of brake shoes and use the long ones out of both sets. After that you should notice a real improvement. And for whatever reason that doesn't work there's always the transbrake. :)
 
That's S-10 manual brake cylinders. Ron's Automotive used to offer a kit with a bypass valve that diverted all the hydraulic pressure to the rear cylinders at one time. With that, the S-10 cylinders, and a set of all-long brake shoes: you oughta be able to hold whatever boost you want. Are your brake drums fresh(round/no scoring)? If they're not: have 'em turned. That'll help a bunch too! ;) I always wonder about the added stress a transbrake must put on the drive train after the tranny. Has anyone experienced a higher-than-usual failure rate on axles/rearends/lugbolts, using one?
 
trans brakes

I installed a trans brake with a 400 turbo trans and was leaving at approx. 15-18lbs of boost when the 28 spline axles and factory posi unit let go. The LH axle twisted off and damaged the posi. I now have 33 spline Moser axles and a spool. Not the best for everday driving but tolerable. With a transbrake everything in the drivetrain will be stressed to the max.
 
Tom Tom Turbo said:
Do I need a line lock to hold that kind of boost or just the bigger shoes in the rear?
You NEED a line-lock. Using a line-lock while doing your burn-out will keep the rear brakes cool and allow you to hold more boost with no other changes. I am able to hold between 12# - 14# depending on track prep with stock brake pads/wheel cylinders. And when staging hold the brake pedal down HARD.
 
neogeo87 said:
I installed a trans brake with a 400 turbo trans and was leaving at approx. 15-18lbs of boost when the 28 spline axles and factory posi unit let go. The LH axle twisted off and damaged the posi. I now have 33 spline Moser axles and a spool. Not the best for everday driving but tolerable. With a transbrake everything in the drivetrain will be stressed to the max.

I say keep it under 10PSI, or just be ready to get towed home. The guy above is a prime example.

Cal Hartline is still running the Buick rear!
 
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