Ok so I've got a wheelhop problem in my 88 GTU, especially on the right side. It hops when I drag race, which I kinda expect and doesn't bother me all that much, but when I'm taking a right turn and give it any throttle out of a corner it hops pretty bad. It doesn't do it on the left side really.

I really noticed it when I installed my nonadjustable Tokico HP dampers with Eibach Pro-kit progressive springs. Before that, it would hop a little bit when I launched it but not in a turn. The thing is, I've checked the big stuff. Alignment is ok. All the various joints and **** are good. The diff mount has been replaced with a competition unit from Mazdatrix. I even changed the DTSS bushings, but all my other bushings are stock.

I had my mechanic friend look at it, and he did a visual inspection and said everything looked ok. He said that maybe there's not enough compliance back there, and that the right wheel is always going to break first because of the right-hand rule and other such physics which I'm not completely familiar with.

I did a search and I found that some people had success with rear strut bars to limit flexing back there. I know guys with Cobras use subframe connectors to reduce wheelhop. Obviously I'm not going to do that, but it makes sense that that would limit flexing.

What do you think? Will a strut bar do anything? I mean, I'll probably get one anyway, but it would be nice if that helped the wheelhop problem too. I don't have the time or ability to drop my subframe and get all the little bullshit bushings replaced, and I don't want to pay someone to do it unless it I'm sure it's going to fix the wheelhop problem.

 

I thought the 88 GTU had the locking differential to prevent wheel hop?

 

It looks like you have fixed everything but the old original sub frame & trailing arm bushings.

You may want to experiment with lower or higher tire pressures.

 

+1 for a little more info on this. Would a pinion snubber have any effect on reducing wheehlop, or does it mostly boil down to suspension settings?

Today I changed the rear diff mount bushings to the Mazdatrix competition style, so maybe that will help my problem with wheel-hop. I'll let you know.

Also... how's your alignment?

James

 

sounds like your lsd is kicking the bucket if it slips in right hand corners but not left hand.

 

Wheel hop is a damping issue.
Something much softer than the chassis is moving around when it shouldn't... I'd start be replacing the old, soft, stock bushings.
Good luck

 

Could always try a SOLID Diff mount

 

connecting the rear strut towers with a bar won't help your wheel hop issues.

My guess is you've got spongy bushings somewhere in there, more then likely either in the lateral link or front of the "wish bone" control arm.

a strut bar will help to reduce chassis flex, it has no bearing on the suspension's travel or the relative rigidity of your 20 year old bushings in the rear.

 

a bigger rear sway bar....

also, launch better.

 

Alignment is fine. The other bushings didn't obviously look destroyed under there but they have 154k miles on them. I think the LSD is fine. I have new redline gear oil and my mechanic says he thinks it's clutching fine. He says right wheels slip first because of the right-hand rule. I'm not completely familiar with all the physics he cites.

As for the "launch better" suggestion, I'm not even drag racing this thing. I've launched it about 3 times in the past 6 months. I get this wheelhop from taking a turn, and often going over bumps. That's what really concerns me.

Regarding tire pressure, I've noticed no real difference between running ~32 and upping the pressure to about 36 when I did backroads driving at Deal's Gap.

My mechanic said that a sway bar might help a little. I know the sway bar has bushings as well as the endlinks. Would it be wise to get the Racing Beat swaybar and endlinks first to see if that does anything? Also, when I'm replacing a swaybar and endlinks, do I need to press out anything? I'm not going to do it myself if it needs a press.

 

I found this interesting FC body brace on a JDM site. I think it would be beneficial to you autocross guys to prevent chassis flex. Check it out has anyone else ever seen it? Anyway I thought it was interesting.