Chevrolet12

I'm taking my 84 to get an alignment in a few days and I have someone going to do it to different specs than stock. Just wanted to see what you guys recommend for specs. It has 20s on it and I don't plan on driving it easy on corners.

93Rubie

You need negative camber. For street use, i would go about .25 a degree negative in the front and about -.5 in the rear. Use zero toe up front and a little toe-in in the rear.

Chevrolet12

How much toe in rear do you think? Would that cause any tire wear? You don't think I should do -.5 negative camber front and rear?

93Rubie

Toe-in creates stability. I would run about .1 degrees of toe-in. Front of tires pointed toward center of car.

Zero toe on the front really helps turn in.

If you want to corner well it takes a certain setup which may or may not work well to your liking on street use. My car is fine on the smooth highway or road but rutted and beat roads its a hand full.

You can go -.5 all around, if you can that much out of the front. That is about max for the LF with ALL the shims removed.

I don't recommend a lot of negative camber on these cars with wide tires unless you plan on doing a lot of very aggressive driving like auto-x or track days. It follows the ruts in the road pretty good.

Chevrolet12

Are those the specs you run on yours? Sounds like you have yours set up decent.

Hot Rod Roy

The Caster spec for your '84 is 3* +/-0.5*. This was increased to 6* in '86. The increased caster will provide better straight line stability. My '84 drives better with the 6* caster, but I don't have 20's. I would think it's even more important with 20's!

Check out this link:
http://www.superchevy.com/how-to/vem...t-c4-corvette/

Chevrolet12

So 6* caster front camber -.25 front toe 0 rear camber -.5 and rear toe.1 correct?

93Rubie

My C4 is setup as aggressive as you can get without changing/modifying parts.

LF=-.5 RF=-1.0 Camber (those are maxed out NO shims)
Caster is whatever because I want the camber I think its around 4.5 or so.
Toe=Zero

Rear=-1 degree camber and .05 toe-in both sides for a total toe of 0.10.

Chevrolet12

Thanks for the help. I went to the alignment shop today to get it done and something has been bent. It's been wrecked. The passenger tire is pushed back about and inch. He said if he aligned it that way it would pull to the right. I need the car to drive straight and corner well. So I didn't have it done. I think I may pull the engine and trans out and get another. What's do you guys think the shell is worth? I was thinking about maybe parting it out...

Churchkey

Suggest a second opinion. A good body/frame shop should be able to pull the frame straight.

Chevrolet12

I agree.. I just don't think I want to pay that much on this one..

l98tpi

Did you take the 84 to a Vette specific or someone that knows C4's. I think the front cross frame can be slightly adjusted on the C4 and will allow the ability to move one side slightly rearward than the other side. I think that this is an technique used to aid in increasing ackerman. I'm not 100% sure because I have never tried this myself, but have read it before.

Chevrolet12

It was a buddy that has done a few corvettes before.. We looked it over pretty good but couldn't find any adjustments that would allow the wheel to push forward.. Maybe we missed something. Do you know where I can find some reading or pictures on that?

l98tpi

I will try to look for the info.

Here is a nice read;

http://www.superchevy.com/how-to/vem...t-c4-corvette/

Churchkey

If all body gaps are acceptable, doors to 1/4's, hood to doors, targa fit etc. the frame may be ok. Check left door gap @ the 1/4 panel & compare it to the right door gap at the 1/4 panel. If more than 1/8 difference the frame may be tweaked. A paint stir stick inserted in the gaps will give a quick visual.

Check for a bent lower control arm &/or A-arm mount brackets.

My 89 & 90 has fixed non adjustable lower A-arm mounts/cross member.

Steering Ackermann is adjusted by changing the location of the steering arm or outer tie rod pivot location on the lateral plane.

Chevrolet12

Control arms etc look unbent.. Would you be able to explain ackerman a little more for me? Would that allow me to reposition the passenger wheel forward more?

Churchkey

Steering Ackermann has zero effect on wheel placement.
Ackermann effect is weather an inside wheel will toe in or out while in a turn. Having the wheel(s) toe out while in a turn is good for a track car.

Chevrolet12

So something has to be bent or moved. My passenger wheel is about 3/4-1 inch back compared to the drivers side.

USNavyVette

How did you measure? What reference point did you use? Did you measure the actual wheel base? Try measuring the same point on the center hub (either the forward edge or the rear edge) between the left front and rear and the right front and rear and see what the difference between the numbers is. I'm not doubting that your buddy knows his stuff, I'm just curious as to how he determined the wheel misplacement.

Chevrolet12

We had it on the alignment rack and the drivers wheel was on the turn table and passenger wasn't all the way on.