I have an '89 Formula, and am looking at a set of Z06 wheels for it.

The fronts are 17 x 9.5 with a +54mm offset and the rears are 18 x 10.5 with a + 58mm offset.

I have two questions:

I'm wondering how the 9.5" wide rims will work under the front of the car. I know I'll have to run spacers, but my question is how well this will fit; especially since I want to tuck them a little further in to correct the "wider in front; narower in rear" stance on the car. I'm also wondering how going to that much wider of a tire will affect the driveablility; the car is already a little "darty" with the stock 8.5" wide rims. They make the wheels in a 17 x 8.5 with a +54mm offset; would that be a better choice?

I'm also wondering how well the 10.5" wide rims will fit under the rear of the car. I'll be swapping over to a 4th gen rear when I put the wheels on, so I'm pretty sure I won't have to use spacers on the rear wheels.

Has anyone done this? Will these wheels fit without rubbing all the time? What tire sizes work best with these rims?

 

anyone?

 

I had the 18" Z06 wheels that were offset for a 4th gen Camaro. they fit pretty decent, but the rear just sat a little too wide for me, and would rub when I corner hard.
18x9.5 front and 18x10.5 rear

 

Thanks for responding.

Was your 4th gen rear under the car when those pics were taken? If so, I'm kinda surprised. I've always heard 4th gen wheels would fit perfectly with a 4th gen rear, but those rear wheels are sticking WAY out. I'm assuming the rubbing you refer was the outer edge of the tire rubbing on the lip of the fenders?

The fronts look like they fit pretty well. Did they rub at all?

 

fronts rubbed when I turned the wheel more than 45*'s, but it isn't an issue, just don't turn so sharp when you are parking.

I have the LS1 rear on the car and the body's of the 4th gens are wider at the rear, they have more rear 1/4 panel going over the tires.

 

Ouch. That throws a monkey wrench in both plan "A" (getting a set of Z06) wheels, and plan "B" (using the set of 4th gen SLP Firehawk rims I already have).

My plan has been to put an LS1 rear in the car, and use one of those sets of rims, but I don't want to if the tires are going to stick out in the back like that. Did they stick out when you had the 18 x 9.5 C5 wheels on you mentioned in this post?

https://www.thirdgen.org/techbb2/sho...hreadid=335445

 

Nope, only the Z06 wheels stuck out, my ZR1's, C5's, and every other 4th gen/Vette wheel fit fine in the fender well.

If you get Z06's offset for a vette, then you shouldn't have any trouble.
there is another member here with Z06's, ask him what offset/backspacing his are.

 

I don't understand the "offset for a Vette" and "offset for a Camaro" part. I've seen these wheels with +58mm offsets, +56mm offsets and +54mm offsets. I wonder which is which?

With there being just over 25mm in an inch, I don't see where there'd be much difference between 58, 56 and 54mm offsets, there's not a 1/4" difference between 58mm and 54mm. Looking at the pics of your car, I don't think 1/4" less "stick out" would have fixed the problem; I think it'd take at least 3/4", probably 1" to make it right. It's too bad, too. Those wheels looked absolutely awesome on your car, except for the way they stuck out in back. My car is black, and I think a set of chrome Z06's would look great on it as well.

How did they fit on the INSIDE of the rear fenderwell? I though I read somewhere on here where someone had put 11" or 12" wide Z06 wheels under their 3rd gen, but I haven't been able to find it. If I remember correctly, he had a silver or gray convertible.

 

There are 2 measurements, offset and backspacing. I am not sure what the offset/backspacing the Z06's had, I was told they were the correct setting for a Camaro.
AFAIK, they only make 9.5 and 10.5 wide Z06's, someone mentioned 11" but no one can find them.
the Silver vert you saw I beleive has the Z06's and ZR1's and the ZR1's were 11" out back.

Now, the Z06's I had seemed to have plenty of space available on the inside, so if I had a 3rd gen rear, I probably could have made them fit better using spacers.

 

Hmmmm .... makes me wonder if I should stick a 9 bolt in it instead of a 4th gen rear. The only reason I'm swapping rearends is to get the disk brakes. Skulte will let you return spacers, as long as they haven't been driven. You could buy a set of 1 1/2", 1 3/4" and 2" spacers, find the set that works best and return the rest.

As far as offset is concerned, I'm pretty sure it's the opposite of backspacing. Backspacing is the distance between the INSIDE lip of the wheel and the mounting surface (the part that mounts to the brake rotor). If I'm correct, a +54mm offset would mean 54mm (about 2 1/4") is the distance between the mounting surface and the OUTSIDE lip of the wheel

 

Oops; I was wrong about offset.

Backspacing IS the distance between the inside lip of the whee and the mounting surface; I was right on that one.

Offset, however, is the distance between the center of the barrell of the wheel and the mounting surface, NOT the outside lip, as I said earlier.

So, if a wheel was 10" wide, the centerline would be 5" (half of the wheel's width). If a wheel had a +1" offset, the mounting surface would be 1" towards the outside lip of the wheel, leaving a backspace of 6".

So, a wheel with a +58mm offset would actually stick out slightly less than a wheel of the same width with a +54mm offset, not more, as I thought earlier.

Also, how about 18 x 12 Z06 wheels? http://www.factoryreproductions.com/z06corvette.html

Check out the 19" and 20" Z06's too!

 

Those are some big wheels.
another thing that turned me off of the Z06 wheels were the price of tires.
18" performance tires are kinda pricey.

 

zepher wat size tires did u have on front and back.

 

295/35/18 rear and 275/35/18 front.

 

what thickness of spacers were you running on the front of your car with the Z06 rims on? your car looks f'n awesome btw, love the silver ZR1 rims and RA1 hood

 

Thanks
I have 2" spacers up front.

 

We just mounted up a set of 9.5" z06's to my borhers car. You absolutely can NOT use any thinner than a 2" spacer. It just barely clears the tie rod and strut. Looking down the side of the fender you can just see the buldge of the sidewall. In the rear he also has 2" spacers and 9.5" wheels, there is a ton of room to the inside, so you could get away with a 1 3/4" or a 1 1/2" spacer. Just have to be carefull not to get it tucked in too far or it wouldn't match the fronts. I'll have pics this weeked when it comes back from paint.

 

would this work 17x9.5 with 275 on all four connors? with koni yellows and ebiach pro kit? and the spacer thing is still confusing me

o yh i got a 87 iroc

 

My main set of ZR1's with my race tires are like that, they rubbed the tie rod ends and I had to grind a little bit off of the tie rod so that it wouldn't rub.
My Z06's may have been the same way (never checked) but since the tie rods were already clearanced, I had no issue.

 

anyone?

 

I run 2001 SS wheels with 2" spacers in the front & a 4th gen rear with no rubbing. I have Tokico springs, Bilstein struts/shocks. It does rub very little in the front on tight turns but it has wore a clearane path in the fenderwell

Chris

 

so how would i gwt it not to rub?

 

I think if I were back to stock ride height it would not have rubbed. It is VERY minor and I would do it again!!

Chris

 

would it still rub even though im not runing a 4th gen rear?

 

its only the front that rubbed. the rears are just fine.

 

awsome, do you have a pic on how much it rubbed? and how would i prevent it from rubbing? wich spacers would i need? sry for takin over thread abit

 

I can get pictures. as for preventing it I dont really know. It is so minor I have never thought about it.

Chris

 

Most of the time the tire rubs on the plastic inner fender at the rear of the fender opening. This is usually at almost full steering. I think you could warm up the plastic with a torch and carefully massage it out of the way. You will also probably rub on the sway bar on the front and control arm on the rear of the chassis, quick fix would be to extend your steering stop as far as you need to. Your going to have to accept the fact that you're going to loose a little bit of steering travel with the bigger rims.

 

so the streering travle loss woudnt be that big or i would nitse a differance and deffetly wana see some pix!

 

The steering travel loss isn't that much at all, but after fitting up the Z06's with 285's on them I'm 90% sure that the "rubbing" that everyone talks about is from the tires rubbing at full lock.

The paint job got delayed a week, so pics will be little ways off.

 

thats coo ust let me know when pics are availbal

 

I have a 1986 z28 and i bought a set of 2004 c6 z06 rims the fronts are 17x9.5 and the rears are 18x10.5. with a 1.5 inch spacer in back i am running 275 drag radials with no problem and 2 inch spacer in front.