hey everyone.. I've got an 86 with a widebodykit on it but some narrow wheels.. The wheels that were on it fit awesome and were even with the kit making the car look great. Well I don't get those wheels... And I have no clue on the specs for them.. I am thinking they were a 10 inch wheel but I do not know the offset..

Any suggestions on a good offset? I would really like to keep the wide tires.. In fact the Tires were a 315/35/17.. Any ideas?

I was looking at the C5/C6 wheels.. Staggered 17/18 or just 17" around.. dunno, The black C5 wheels that are on it now look awesome but they aren't wide enough.

 

wide or deep

you can go 11 or 12 inches wide on a c4 but the offset I believe on your year car is 36

 

Yeah.. 36 is the factory offset.. But with the widebody kit on it they don't sit even with the kit, so it looks retarded.. I would like to put the widest tires possible with a good offset to sit even with the kit (approx. an inch past the fender well)

 

I'd guess what you need to fill the wheelhouse in the rear is 11" ZR-1 wheels which have a 36mm offset. If you wanted to make these match (all 4) I believe you would need to do the 9.5's from the same year ZR-1 with a 19mm spacer.

The exception would be if you found some after-market 5 spokes (ZR-1 style) that offered the 9.5's in the early 38mm and the rear 11's in the 36mm. There are combinations like this available from time to time.

Your other option is later wheels with 19mm spacers at all four! I have a set of black spokes 9.5's (56mm) and 11's (50mm) that you could do this with. The plus to a rear fit with spacers is that you can customize the placement with different thickness spacers.

The previous owner kept the wheels from the car?

Get some snap-shots of them and get dimensions of them if you can and duplicating "the look" of the car before the wheel change might be easier.

 

Why not just measure the tire distance to the edge of the fender, and get some spacers off that E auction site?
I mean you like the wheels you have, so just use them.

 

Your best bet is to go with a custom wheel. John @ CCW Wheel will make you a 3-piece forged custom wheel for your application. I don't know what his pricing is these days, but they used to run $1,800/set of 4 when I bought mine 6 years ago.

Here is the information he'll need from you...put a straight edge (steel) ruler on the face of the hub and take the measurements.

I'm guessing with the widebody kit on it, you'll be able to get a 12.5" - 13" rim under the back with a 335 tire on it (I know I've seen quite a few on some C4 ZR1's).

Whatever you do...DON'T put spacers on it!!! Spacers put way too much stress on the bearing hubs, and unless you really LIKE to change them out every few years (with the associated costs) I'd steer well clear of them...especially if you drive it hard. If you want to autocross it...forget it. I don't even think they'd pass it in tech.

 

I agree, spacers are generally a horrible thing to put on your hubs. Not only do they create undue stress on the hub, they also tend to stress the studs to the point of randomly breaking. Also, if you are trying to push it out nearly an inch, you would have to find some extra extra long wheel studs to do so just for the lug nut to have enough thread to bite... to me, all things considered it's not worth the safety risk. Doing it right may cost more right now, but will be cheaper in the long run.

 

FIKSE Wheels for sale 17x9.5 Fr 17x11 Rr Tires (275x40zr 17)..(315x35zr 17)

 

I have spacers on my wheels, and there aren't any of the presupposed problems

 

Same here. I dont think spacers are as bad as everyone makes them out to be. I could understand having problems with something like a 2" spacer, but anything 1" and under wouldnt cause any issues.

 

You guys keep thinking that...

There are very valid reasons racing organizations have banned the use of spacers...wheel studs being a small part of it. I've seen at least 5 failures of them on the track...before they said enough is enough. It's a safety issue, and one that is easily avoided just by getting the proper wheel offset/backspace in the first place.

Do what you want, but it isn't worth it to me...I have a lot of other things to worry about on my car without wondering when a wheel stud is going to break and the wheel comes off.

 

Like I said maybe it happens with bigger spacers. My grandpa ran 3/8" spacers on his race prepared car for about 15 years with no issues. I have run 1/2" spacers on the back of my car for a couple years and just replaced the factory OEM bearings in the spring. I have done a handful of events this year and the bearings are still tight.

I dont have a whole lot of money for racing so I like the fact that I can run the same wheel on any corner of the car to get the most life out of my tires. This requires me to run a spacer in the back. If I had an unlimited budget I would use front and rear specific wheels.

 

I'm confused...why would you need to run a spacer on the rear? My '91 CAME with 275/40-ZR17's on all 4 corners from the factory. Same size wheels, too. I swapped them around all the time.

On the street I now run 295/35-ZR18's all the way around...no spacers needed. I run CCW 11" x 18" rims for the track with Goodyear Eagle 25.5"x11.5"x18" slicks. I run a 1/8" spacer on the back to keep the tire from scuffing the rear sway link on heavy side loads...but that's because I put as wide a rim and tire as I could fit on the car. Looks pretty hot standing still as well

Your 1990 has the same 56mm offset front/rear as mine...just don't understand why you'd need to go through all that if you don't have to...unless it was the rims you bought???

Is that Aaron's car next to yours? Been a while since I've been competitively racing in NCCC...too much stuff going on. We used to go head to head at convention a lot. Always fun to race against. His CCW's look vaguely familiar...

 

Yes thats Aaron's car! Mine looks like a heap next to his, cause its mostly stock. He always did do well at convention. I dont do NCCC stuff anymore Im trying to get into NASA. Its way more seat time for the money.

I run spacers because the 17x11s, 50mm offset, I had hit the spring bolt in the back, and come close to the muffler. I also like a little bit wider track in the rear, but am restricted to a certain wheel size in my class.

Also, on my street wheels I have to space the front out a bit to clear the C5/6 calipers, and I run spacers in the back to even out the look. At the track though its just one in the rear.

You got pictures of you car? Did Aaron's CCWs come from you?

 

You were talking about longer wheel studs?


This is the spacer that is currently installed.


This is the C5 wheel installed with the spacer..


This is the ZR1 wheel without the spacer


This is the ZR1 wheel with the spacer


I think it looks great with the spacer and the ZR1 wheel.. So with the wheel being a +36mm offset and the spacer being 1" think i would need a +12mm offset wheel right?

This is the look i want.. maybe a wider tire if possible

 

NOW it makes sense...

I have a few pics HERE on the web site...some are on the home page, and a few more on the "Racing the Z07" page.

Nope...he didn't get those from me. Mine are still sitting in the shed with 6 year old super-soft Goodyear Eagles on them (although by now...they MIGHT not be so soft anymore ) At least...they BETTER still be there (or me and Aaron might have some words ). We got ours about the same time...

I hear you about the seat time...too bad you aren't closer to us here in Texas. You could have some fun on the Open Road Races and REALLY get a thrill ...59 miles of flat-out, fast as you have cojones for (or your car is teched for) fun.

Nevada does a few every year as well...THAT is worth the price of admission! We have a few good NASA events down here every year, too...about 6/yr. TWS and Hallet are the best...

 

These 2 shots show you exactly why spacers are not a good ides...especially those you have on it.

See, the wheel actually sits on that little lip on the hub in the first shot. Then the studs are used to hold the wheel to the hub. IF your spacer had a corresponding lip on the wheel-flange side then it would be a little better, but still stresses the studs. But as it is ALL of the weight of the car is sitting on the studs, not supported by the center of the hub.

Like I said before, talk to CCW. Looking at the rear shot, it'll look SWEET with a set of 335's in there. Just think of the rear view of a Viper and those massive steamrollers they have for rear tires and then imagine them on your car. Lots of grip...and good looks to boot. Should fill it up nicely

 

When I mentioned "spacer" I meant a "hub centric" spacer that can be used for "fitment" !! I doubt there are issues with a "hub centric" spacer that is "tailored" to the hub and the wheel that it is being used on! I don't see issues with 20mm or less.

The spacers in the images in the previous couple posts need to be removed!

My wheel spacers fit my hubs better than an OE wheel and the wheel is a better fit to my spacer "hub center" than the wheel was to just the hub center and the OE wheel!

Regarding spacers and "sanctioning bodies"! They certainly must pass tech but I'm sure there are "specifications"!

There are wheels that actually have a "spacer" of sorts that is bolted to the backside to adjust fit and reduce back-spacing!!

 

No worries guys those are just Mock-up spacers that were made by us to see how it would fit!

But back to the offset deal i could convert it over to newer hubs and run the 36mm wheels right?

 

Again...I come back to the same questions...

Why do you want to do something outside of the box?

Will it work? Maybe...a BIG maybe.

Will it change the setup? Most likely

What will work and NOT affect these factors? A set of rims that are MANUFACTURED to the specifications of the application!!!

You can try the hit-or-miss approach to this...or do it right the first time. I've learned (read this as MANY $$$$) that while it may be "cool" to do it different, it usually costs many more dollars in time/testing/fabrication than to just bite the bullet and do it right the first time.

You'll NEVER get a set of OEM rims to fit a set of 335/35-ZR17's without cutting, adding a spacer to the wheel and welding the OEM rim.

Can it be done...YES!

BUT...the last I heard it was $250/wheel to widen an OEM ZR1 wheel 1"...$1000 for 4 CAST wheels...plus the purchase price of the OEM wheel. So add another $500 (minimum) for a set of good OEM wheels and you are already in the ballpark (+/- $300) of a custom set of 3-piece FORGED wheels.

Why would you want the headache?

Sell the OEM wheels and order a custom set...

PLUS 17" tires are starting to get harder to find...just as a comparison...6 manufactured in 17" (335) vs. 8 in 18"...plus a lower profile to boot. It's only going to get worse as time rolls on.

ANY spacer that adds length to the wheel stud is asking for (eventual) trouble...period. And especially if they are fabricated from aluminum.

Will they work for a street car? Yes...conditionally (for a while).

Is it adding undue stress to the rear bearings, hubs & studs? 100% YES!

The engineers designed this stuff with tolerances...and they NEVER anticipated someone would try to add 1" (or more) of spacers to allow fitment of a later model OEM wheels (or one not available on that particular body style like C4 ZR-1 wheels on a non-ZR1 C4).

Add to that that the OEM cast wheels are HEAVIER than forged ones and you have additional forces at work. Now you have more rotational mass at work. It reduces the rate at which the engine will rev, will affect the suspension weight (try lifting 5 lb weights with arms fully extended out vs. 10 lb weights...big difference).

I just don't get why some want to force a square peg into a round hole?

Can you do it? Yes...

Are there better ways to expend your time & energy? Certainly yes!

What's your time worth? And the multitudes of variations to get it all right?

Just some simple advice from one who has been there, done that and has ALMOST all the T-shirts. Go the easy route on this one...save up the money and BUY the correct rims.

Sell the OEM ZR1's to offset the costs of the new rims and you are WAY ahead of the game. Your new rims will bolt on (with no shims/spacers/extended studs), will look great and have more strength than ANY OEM cast wheel...period. You'll have a wheel that NOBODY else in your club/town/city has (most likely) and it will set your car apart from all the others (much like your body kit does).

I've been there...find a buyer for your ZR1 wheels...get a sweet deal on something unique. It'll set you apart from the crowd.

You'll still have your hair AND you'll be happier...