So I have a 1988 IROC-Z, and i've used the PST front suspension rebuilt. thing is if i turn my steering wheel to the right, i have massive angle difference between my passenger and driver's front tires. and it is amplified when i go in reverse, to the point that i can stop my car when idling in reverse.

would appreciate input before i spend a ton on this car

 

Sounds like you need an alignment and some new Tie rod ends.

 

well, the pst kit swapped them already. thats the front end kit

 

iv got the same problem on mine, if im trying to turn sharp while just idleing i can actually stop the car so i gotta give it some gas.

 

what have you done about it, or are you just living with it? did you do anything to create this situation?

 

Mine rubs on the headers and I'm sure it's rubbing elsewhere (like sway bar endlnks or something). I hate to say it but I believe that GM just designed these cars this way for some odd reason.

 

If the car originally came with 15"x7" wheels, I believe the internal steering stops in the steering box are different & could cause rubbing on 18"x8" or larger wheels, but I would expect that to cause rubbing more than just in Reverse on one side. Maybe new bushings could push things back to where they should be & the old bushings were bad enough to allow enough slack for it not to rub?

 

Well of course the wheels turn different angles. The inner tire has to turn tighter, it's travelling in a tighter arc.
When turning right, the right wheel turns more. When turning left, the left wheel turns more. This is why the center link, between the tie rods, is back close to the crossmember. Look at where the outer tie rod ends attach to the spindles. When the car is going straight, then both of them are forward of the center link. When turning, the inner effectively moves rearward.

 

done it ever since iv driven the car, i just live with it because it seems to be a common problem with our cars so i just live with it. only suspention iv done is the sway bar end links for both the front and rear

 

Well. It's the outside tire that is turning more. The inside wheel has less angle, as if the Ackerman effect has reversed on the car. I'm stumped, chevy quoted me over $1000 to diagnose it cause it requires a full tear down.

 

Right: Ackerman angles have little effect of value except at very low speeds. That is not a factor at any speed above about 10 or 15 mph.

Having the car toe in more at relatively high steering inputs for high speeds, makes it feel more stable .... at high speeds. Think, going around a 35 mph expressway ramp at 85 mph. (not that I would ever allow myself to get caught doing that, just sayin...)

Guess which situation these cars are optimized for: parking lots, or high speeds.

Like alot of things about car design, it's a compromise. You give up some one thing, to improve some other. I have for example (my wife's car) a Cadillac with the high-HP version of the Northstar engine, which is BAD to the bone; it'll SMOKE a Monte Carlo SS or a TPI car so bad it's humiliating; BUT, the high-HP version of it, doesn't idle smooth. Too much cam lope. The old people (hey! I resemble the implications of that remark) actually take their cars back to GM to have them put the low-HP cam in them so they idle smoother. Idiots. Kinda the same deal here.

In the case of these cars, I personally LIKE that they gave up "ideal" low-speed parking-lot manners, to improve high-speed handling. In fact I have made every possible effort along the way for the last ... almost 30 years ... to FURTHER tilt its compromises that way. So my car does the whole parking-lot boogie thing REAL bad. I kind of like it that way actually. Now maybe when I get OLD, that'll change; but no signs of that just yet.

 

Mine doesn't boogie (lol) but it does rub and squeek and all that good stuff.. Pretty annoying actually.. High speed is definitely stable (went 200km per hour and turned at a 70km per hour turn up north on twisty roads.. Roads were very flat though. I could have gone faster but you know.. Girlfriend was in the car

 

Ok. Cool. But I don't even have high speed stability. Maybe I'll scrap the car and find another one that's in better condition. Going forward is decent, but backing up is a pain. I have no idea what I'm going to do. Even hitting the little turtles on the freeway makes the car loose. Les schwab tried to align it, but it didn't help any, so they didn't even charge me to go thru with it. I'm stumped

 

Well, there could be many things here.. Let's just be clear, when you're turning LEFT you are saying that your driver's side has less angle than the passenger side? That could mean a bent part perhaps.. You should get an alignment and check your SAI (steering angle inclination) and after your car is aligned, the left and right SAI should be close to equal, if not it could something is bent.

 

Yes. If you were to imagine circles created by my tires, the inside tire makes smaller circles than the outside. All the parts are new. Inner and outer tie rods, drag link, idler arm, even a new steering box. New bushings in the lower arm. Already aligned by a shop. He was stumped as to the cause. Referred me back to chevy when they quoted me over $1000. When I measure from rear tire to front, there is about .5" variance, but was told that's normal. The parts underneath don't look damaged. I can't keep pouring money into it.

 

as stupid as it may sound, the drag link was installed backwards. the tie rods (the bolt/thread is the top, thus making the "ball joint" the bottom) were installed with the thread facing the rear. /---\ instead of ___---___ if that makes any sense. the dotted line is the drag link, the solid lines were my tie rod assembly. i'm about to install the tires and will give an update afterwards.

one last thing, i have 15x7 6mm offset wheels all the way around. i thought iroc wheels were 16's with different offsets for front and rear. do i have bad wheels, they say chevrolet in the center cap. when I get inside, i'll upload pics of everything

 

any improvment?

 

Thought I updated this last night. Yes, I had great improvement with my turning. If I'm rubbing I barely feel it. But I can now to lock to lock while in reverse. I didn't drive it much due to it needing an alignment and burning unnecessary rubber. Even the steering feel has returned and the car tracks safely. Even changing lanes on the freeway felt safe. I can't believe none of the shops noticed it, or chevy did but wanted a grand out of me.

I'm not certain how I figured it out. But once I looked at it, it just seemed wrong. Lucky guess.

Thanks for all the help

 

Imagine losing a 1000$ just for that? Holy rip off batman!!

 

I also have this problem to a point where the passenger wheel took off the bottom plastic clip of the inner wheel liner. While reversing in idle the car would even stop/break against the plastic.

I checked already that the tie rods are correctly oriented as I had disassembled the whole steering a couple of years ago (has been sitting in a garage for most of the time ever since). The car had been professionally aligned and I remember giving him the specs for a performance feel.

I saw some people say it is due to this performance setting however one thing that came to my mind is that when I replaced the A-arm bushings with energy poly (was extremely a big pain) the bolts were lose in the bushing’s center tube. I had kept it like this ever since as i didn’t feel any lose play in the a-arms before I assembled the springs. Could it be the a-arm moving when reversing? I would need to drill wider holes in the stock k member to have a good fit bolt in the energy bushing’s center tube. Is this normal with energy poly bushings?