Launching a T56

[woody80z28]

How do you do it?

I swapped one in my 80 and I have a tough time launching it at the strip with 275/60/15 MT Drag Radials. I have to pussyfoot the clutch or it blows the tires away. SPEC 3+ clutch w/ 2.0-2.1 60's.

Any tips? I've heard that wrinkle walls would be better for a manual trans than the drag radials.

[Fastbird]

Each car is different. Lots o practice and trying different techniques. Don't be afraid to launch high rpm and do a lot of slipping of the cluth.

[96LT1355Z28]

It can be done with drag radials but not without a decent amount of money spent on shocks and suspension components that work together and are setup for your cars weight. It's much more common to use a set of bias ply rear tires in a stick car. This is because we shock the driveline very hard on the launch unlike an auto that has a converter to manipulate engine torque and even with a transbrake doesn't hit the tires near as hard. The soft sidewall in a bias ply softens the hit and is much more forgiving than a radial, if you spin a radial it's nearly impossible to get it to recover without removing all your power and starting over. Depending on your setup either tire can work it just boils down to how much $ and seat time you want to invest! Also a 2 step helps tremendously with consistency.

Try adjusting tire psi, a radial probably won't want less than 15 psi. Adjust in 1 pound or even 1/2 pound increments and try to launch at the same rpm each time. Change only one thing at a time and keep a log of each pass. Try and stay in the same lane at the track, lanes vary and data collected is not useful without consistency. You'll probably have to launch from idle or just above it till you can get the car to bog by adjusting the tires, then start upping launch rpm. When you let off the clutch bring your left foot straight back, don't "side step it" that will only make your spin worse. Seat time and data collection will tell you what works best for your car.

BTW a run down of your cars setup would help, power level, suspension components, etc!

[popo8]

+1 on a LOT of clutch slipping......

[BLK95-Z]

+2. Launch at a high rpm and controll the power with the clutch. Kyle and Tanner might have a few secrets to share....

[popo8]

More importantly... Is that 1980 an LT1 car??? If so, I wanna know MORE!!!

[97firehawk]

I can not hook either I smoke myn all the way thru the 60 feathering it I'm goin full slicks .I've played with different launch tricks nothin is working for me .

[woody80z28]

Thanks for the replies.

More seat time would be the best, definitely. The tracks around here are always packed and I'm lucky to get 3-4 runs in a whole day...I think that's what makes it hardest.

I've played with tire psi from 15-20 and it's best at 15. I did dead hook it once on a 4500rpm dump, but it put the pinion through the back seat and snapped the driveshaft off. I think if the rear held it would have had some nasty tire shake. That was my first time at that particular track...and they prep much more than my usual. Now I have a welded, Moser-equipped 8.5" 10-bolt.

The 355 is a 10.55:1 SBC with Vortec heads and an old Comp 280H ft cam with an RPM Airgap intake and 750 carb. The springs (coil front, leaf rear) are Hotchkis corner carver stuff, not drag springs and the shocks are regular KYBs. I thought about a shock swap for track days. I do have adjustable CE Slide-A-Link traction bars that preload the suspension and eliminate wheel hop.

The tires seem to be the biggest problem though. What do you bias-ply guys use? I hear good things about the M/T ET Drags, and in my size there is a "stiff sidewall" option that some NastyZ guys run - but they are auto cars. I'd assume I'd want the softer ones.

[Formula383]

As far as bias ply tires are concerned, cars equipped with manual transmissions or cars with heavier race weights will want to use a stiff sidewall slick. The idea is to allow the suspension to absorb the shock instead of the tires and creates less tire distortion. I have yet to cut a 1.3x 60', but I have been in the 1.4x-1.5x range fairly consistently over the last few months. If you want to launch on DR's, you will have to get the suspension stuff right. Autocross or road race suspension won't cut it. Adjustable shocks and correct springs in the front help tremendously and are almost a necessity to get any car to launch correctly, especially 6-speeds.

Here's a few vids from a weekends ago. I'm leaving at 6,400 RPM off the 2-step. I'm not side-stepping it but I'm not feathering the pedal either. I just release the pedal as if I was driving it down the track. It's good for 6-speed cars to have a small amount of controlled tire-spin when launching. Slicks are MT 28x10.5 ET Drag S (stiff sidewall) at 11.5 PSI.

1.45 60' on the 2nd pass
http://www.youtube.com/watch?v=ZEFaS3jPrbk

1.52 and 1.54 60'
http://www.youtube.com/watch?v=g2K8v...feature=relmfu

Same as the first run in the video above. Different angle
http://www.youtube.com/watch?v=TIXPT...ure=plpp_video

[CALL911]

Kyle, do you rub at all with a 28 inch tire?