z28boysteve

iTrader: (9)

Ok so first time out with my 2002 trans am (402 with PT101, 1200 flywheel horsepower, 4,000 stall circle D, Th400, 3.88 Gear 9" 3,150 lbs MT ET Drag 28x11.5x15s)

Run one... Shocks at 8 clicks loose, slicks at 14 psi.. 3,300 launch on two step and trans brake.

Car reacts lazily off the line and turbo blows the tires off makes slight right and I lift all by the 60' Casey Rance my tuner says it didn't hook because we babied it so bad off the line that when the turbo did kick she spins.

Run two.. Shocks go to 13 clicks loose, tires down to 13 psi two step to 4,400

Spool up on the line to 4,400 and probably 10 PSI.. Car hooks perfect and launches like a rocket, I instantly loose sight of the track and car continues up and up past the 60' but I feel it pulling way left and lift because I have no idea where I am, I come down just over the center line and it hits hard. I stop and shut it down and get out and see oil coming out the pan.. damn.


Ok so the day before racing I took the car and got it aligned The rear thrust angle was off 3/10 of a degree so it got straightened back up and I didnt even think to re-adjust the pre-load on the wolfe anti-roll bar since it was completely lost moving the rear end. I completely forgot now how to adjust the preload correctly on these things where does everone run theirs at?

and the 3.88 gear..well I have a pro-geared rear center section so I cant get much higher than 3.88.. Is there a way to make these gears work for me without wheelstanding so bad?

Should I tighten the shocks back up or leave them set at 13 loose and make some suspension limiters?

Is the lack of preload what made the car turn left?

Just wondering where most people sit on a setup like I've built.

Phil99vette

iTrader: (11)

Make suspension limiters, start at 3" of travel, back the boost down a # on the hit and see what she does.

z28boysteve

iTrader: (9)

I'm going to have to get my tuner to look at the log to see what boost I launched at for sure. and I have nothing to control boost other than a directly plumbed waste gate.. what do I need to put on there?

Phil99vette

iTrader: (11)

The fastest way is no boost controller and get the chassis to work. You've got a good 6-7" of travel now, cut it in half and see what she does.

1320

iTrader: (6)

That and just turn the 2 step down......and work your way up 100 rpm at a time....

z28boysteve

iTrader: (9)

Ill set it up next time for a 3800 rpm launch with 3" limiters and shocks still at 3/4" loose. Also need to set my preload on the sway bar but not sure which end to tighten to get it to steer which way, if the car went straight I may have been able to ride it out...or flip it over lol. I also need to I think raise the car back up 1" for a little more cushion to come down on. She's in the weeds now we did it thinking the car would be less likely to wheelie that way.

z28boysteve

iTrader: (9)

Oh, and the car 60'ed 1.36 on the rear tires, what is that in front tire land? lol

98Z28CobraKiller

iTrader: (17)

Well, the first thing is that your converter is not a 4000 if the transbrake goes to 4400.

The good news is that the car hooks. Tighten the rear all the way and tighten the front all the way, then try it again. if it feels like it's getting away from you, you can pedal it down until you find the right launch RPM/boost combo. Another way to bring it down easier is to short shift when it's getting away from you.

You really should be able to make it work without limiters yet as you don't even have a controller.

1320

iTrader: (6)

its odd that it drove left. Ussually they drive right due to the rt rear tire spinning more then the left. The left tire gets pushed into the ground while the rt is lifted.

Measure the tires circum.....and I think ......tighten the rt rear shock....and or lighten the left.....and maybe get someone with a good video camera next time to see what its doing.

98Z28CobraKiller

iTrader: (17)

Or just get rid of the slicks and get some DR's. Not sure if this is your first go around at these power levels but I find slicks to be a wild ride at 140+ MPH.

MUSTANGBRKR02

iTrader: (91)

Might need Madman SYA bars too! Travel limiters sound like a must also.

z28boysteve

iTrader: (9)

Well there's the first problem, I built myself a $55,000 car (all parts expenses I did all the fabrication and building myself including the turbo kit and cage) and I still have stock rear shocks lol .. I have a full spool so I don't quite see how one tire can spin and the other hook.. and with my converter I can trans brake all the way to 7,000 if Im on the trans brake long enough with no two step.. it stalls up to 4k initially then the turbo starts honkin real hard and it creeps up and up through the converter.

z28boysteve

iTrader: (9)

I would like to use my wolfe anti roll bar to "steer" the car if possible .. If I apply a downward force preload to the right rear will that make the car go right, or left? (if it was already going straight)

1320

iTrader: (6)

That would make the car drive left......

But you cant see how one tire can spin, even with a spool? Think about a funny car, crazy wild ride, but still has a spool.....

If the rt side tire hooks better then the left it will drive left, the spinning tire acts just like a turning brake on a sandrail........and it goes that way.

hawk584

iTrader: (1)

skid plate

kmracer

iTrader: (1)

thanks for the input.


https://ls1tech.com/forums/drag-raci...very-long.html

http://www.baselinesuspensions.com/info/arb.htm

Fbodyjunkie06

iTrader: (10)

This, if it stalled to 4400 it's not a 4000 but that is moot.

Going from 3400 to 4400 prolly wasn't the best idea on slicks with the shocks that loose.

Get some limiters like Phil said, adjust them to what he said.

Bring the rpm down to 3800-4000 and a little less boost(let off the button sooner).

Get a electronic boost controller once you get the chassis sorted out and figure out how to bring the power in linear and get the car to move foward and not up.

Any videos of said wheel stand?

Fbodyjunkie06

iTrader: (10)

Do that too much and you will burn your foward clutch up.

Ask me how I know......

z28boysteve

iTrader: (9)

No, no video or even pictures !!! thats what I most upset about because I dont plan on doing it again, well untill at least I get the car completely sorted out running straight 100% of the time and get some sya bars then I may try just once for a photo op...

I know people were out taking pics too because I saw camera flashes but I dont know who.

z28boysteve

iTrader: (9)

also, how do I know if the track was what made me run left or the suspension?
Im going to guess the correct approach is to dial in a long soft LOW wheelie then get the car to go straight?

Also the wheelie I pulled was a "long soft" wheelie, the car wasnt coming down at the 60' it kept climbing to about 90' when I lifted. On the hit the car did about 2' and by the time I lifted I was around 4' I dont know if this helps diagnose anything. But the plan is still 3900 launch 50% on the front rebound and some madman SYA bars.. Keeping the pre load neutral in case going left was a fluke for just that pass. The aligment machine said the tires were damn close in circumference about .65" off I forgot which way but I may want to stretch the smaller slick I suppose.