I Want Car To Go Straight


Tag - WUTSA V8
OK, after getting totally pissed and letting the GN sit for over 2 months without even caring to start it, let alone drive it, I have finally calmed down enough to attempt to try AGAIN to see what my problem might be. I thought I'd try asking again for suggestions on here for WHERE to look to solve this problem. I know there are plenty of guru's on here so I'm hoping SOMEONE can come up with a solution.

The problem is---- if I roll away from a stop and at about 15-20 MPH I give it about 1/2 to 3/4 throttle (no way flooring it), the back end breaks loose and I'm immediately looking at 2:00 and have to let off to straighten out the car. I can't even try to race a Honda across the intersection let alone anything serious because I go sideways.

About 2 months ago I spent over $600 to get a new H&R rear bar installed and had all the rear suspension components thoroughly checked out. I was told this would fix my problem but it didn't. Just to be clear, it was doing this before we installed the H&R bar.

Here are the specs.
low 11, high 10 sec 87 GN - see signature for specs.
Stock posi rear end, rebuilt less than 4000 miles ago
New H&R rear bar - set up with neutral preload as instructions suggest
Boxed stock upper control arms with stock rubber bushings
Aftermarket lower control arms (like Southsides but not) with poly bushings and grease fittings in each end.
Monroe stock type shocks
Aftermarket rear springs that Kirban sold many years ago
2 rear air bags but no air in them
Tires are 275-60 15 Nitto drag radials. They still have good tread on them but are about 6 years old - about 24 psi I think
All body bushings replaced including adding the GNX bushings over rear end
Pinion snubber
Front bar still on and years ago added the cross braces under radiator
Rear seat cross braces
Battery relocated into spare tire well

I'm looking for suggestions but I have a hard time thinking that changing the brand of shocks or lower control arms, etc will solve the problem. I was told the H&R bar would make it go straight but it didn't.

I am assuming I go sideways because both tires are not gripping equally. I don't think I have a rear axle that is shifting all over the place. Flipping to the right as hard and quick as it does makes me think it HAS to be because of unequal traction.

I can't figure this out but if it is immediately spinning to the right, which tire is gripping and which is spinning? Drivers side grips and pulls that side forward?? I have so much torque at part throttle that there is no way on the street to keep the tires from spinning but it sure seems to me that one of them is spinning a lot while the other is gripping.

Here is the only thing I can think of as a possible problem. The guy that rebuilt my posi years ago was a serious drag racer. He said he put an extra disk or 2 in the posi clutch pack to make it grip tighter. Is there a possibility that it is so tight that it isn't working properly and locks up one side and not the other?

We adjusted the H&R bar neutral like instructions said. Should we try pre-loading it or putting air in the passenger rear air bag?

All suggestions appreciated.

Tires are 275-60 15 Nitto drag radials. They still have good tread on them but are about 6 years old - about 24 psi I think
That or it could be this also...If you are spinning your cahances for gettin outta control are much greater ive heard you gotta heat the hell outta new nittos to make them hook let alone 6 year old ones:eek: Its the combination of the two if you were hooking it wouldnt be as bad but at the same time spinnin in a str8 line is always better than doin donuts;)
Tires are 275-60 15 Nitto drag radials. They still have good tread on them but are about 6 years old - about 24 psi I think

All suggestions appreciated.


I'd start by getting new tires .. 6 years old they are prob like rocks
Sounds like you are putting to much power thru the Nittos. I never had good luck with them and you are putting out a litle more power than i was at the time. Try some MT's or another good quality DR. Doesnt sound like the posi to me, i think if it was going you'd get the one wheel peel and not really get the back end moving around like it is.
This may sound funny but you might just need a good alignment. It sounds like you have severe bump steer but it could be the posi but I don't think so.
X2 these WILL solve your problem, your posi is working the way it should thats why the car goes sideways. if it were broken only one wheel would spin, and it WONT go sideways.

Crap tires
BTW good luck getting an extra disc in that diff without doing machine work.
Thanks to everyone for suggestions.
I know the posi is working or like was mentioned, it would act totally different.
I am having a hard time believing that old hard tires are the problem but maybe I'm missing something. That would be like having little tires on there, they would just go up in smoke.

AGAIN the question and problem is WHY does the car make an immediate turn to the right? Is that normal? What happens to the rest of you guys that have this much power when the boost comes in? Do you spin the tires but go straight or do you spin and turn right? I guess that is the question. Am I experiencing something normal (too much power for the tires and they spin and you go right) or should they spin but stay straight?

I don't ever remember my old big block vettes doing this - they would break loose but the car stayed pointing straight.

Again - thanks for any and all ideas.
Old tires sounds like it to me. They aren't small, so you are getting some traction, and that is what is pushing you sideways. If you had small tires as you said, you would just light them up, but your wide tires are getting some traction, just not enough, and not even across both rear tires. See if there is someone that you can borrow a set from. For a couple of quick blasts to see if that makes a difference. I've never used Nittos, and not 6 year old ones, but with the power you have, you need good/fresh rubber.
I agree that trying someone elses newer tires would answer a lot - the problem is I have extended wheel studs on the Moser axles and no one else has. I can mount their wheels but not use their lug nuts and different mags take different lug nuts. Gotta find someone who's wheels will take my open ended lug nuts. Time to do some more looking around.
Buy some new lug nuts to go with whatever wheels you have available to try. How much is that going to cost? Not much, and if they are just steel wheels, you don't even have to buy chrome. How much money is tied up in your car, and how much are you planning on throwing at it to fix the problem? Alot more than 10 lug nuts are going to cost you.
My car will burn rubber straight, to the left, or to the right in second gear 1/2 throttle depending on if I hold my wheel straight or turn it a lil which ever way. I'm with everybody else and say get some Mickey Thompson slics. Thats what I did.
mine goes to the left pointing say 11:00 thats w/ my BFGs on though
245/60/15 (but is moving in a strait line)thats from a rolling run like u said in the beginning post, not a full throttle!! though either,
but catch traction and just before she hits second then she kicks to the right an pointing at 1:00, but when I have my ET streets on, she goes strait as an arrow, as long as theres not a groove for bias plys to catch....
anyone using the ET street radials?