F-Body with 18/19 C6 wheels - Help with tire size

Hey guys! This is my first post on this forum.

I have done lots of research online, and can't quite find a definitive answer to my question. I just bought a set of C6 wheels and I'm struggling to decided on a tire size.

Originally I planned on running the stock Vette size, but then I found out that there could be some ABS issues running tires with over a 1" variance in overall tire diameter. The corvette tire sizing has a 1.13" difference between the front and rear tire diameter. My questing is, what is the exact limit that will throw the ABS off, and cause issues?

If I run 255/35/18 up front and 295/30/19's in the rear, that would be a .94" difference in diameter. Would this be OK? I like this size combo because the sidewalls are close to the same height.

I also bought a set of 1.25" wheel adapters for the rear wheels on ebay, so I've got that covered.

I've seen a lot of posts on C6 wheels, but most of the information is old and incomplete. So any help on the topic would be great!

I run the stock vette sizing, 245/40/18 up front and 285/35/19 in the rear, with no problems. In the rear, they are very close to the inner fender well/shock mount using the 1.25" adapters, but fit nicely.

Thanks for the reply!

What brand tires are you running?

Falken ziex in the front, goodyear eagle f1 in the rear. The good thing about using the f1's is there's a lot of nice used ones floating around since they were the oem.

I think I'm going for the BFG KDW2's or the Michelin pilot super sports.

You are the second person now that has told me they run the stock vette size with no problems, so I think that's what I'm going with. But it never hurts to get more peoples opinions!

I would, unless you don't mind possibly have to roll your wheel wells or trim the shock bracket.

Here's a couple pictures of what the offset looks like with the 1.25" spacers and stock vette size tires.
My 00
http://i275.photobucket.com/albums/j.../Photo1008.jpg
My 98
http://i275.photobucket.com/albums/j...720_124325.jpg

I don't want to roll the fenders. For me, that's not an option.
I'm almost starting to think I should try and find 2 more 18x8.5 wheels and run 18's. Damn it.

Well that's my point. You stick with the stock corvette size and 1.25" spaces, you will not have to roll the fenders wells.

Thanks, man. I appreciate your help!

I just tried to call my local tire store (that is supposed to be the best in town) to get tire prices, and got an earful of babble about how dangerous wheel adapters are. He pretty much said I was going to die.

So I guess I will just order tires from tirerack.com

Just an FYI: I had a customer come in with a third gen Firebird convertible to have C6 ZR1 replicas installed...with spacers...no issues. I have NEVER heard someone advise against spacers. Ever.

Quote:

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Originally Posted by Natronathon

Thanks, man. I appreciate your help!

I just tried to call my local tire store (that is supposed to be the best in town) to get tire prices, and got an earful of babble about how dangerous wheel adapters are. He pretty much said I was going to die.

So I guess I will just order tires from tirerack.com

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I would be concerned with adapters if you were dragging the car and/or putting out over 500 hp. But normal driving and power, I've never heard of anyone having issues.

Tirerack is the way to go on tires, anyway. I've never had a local store beat their pricing.

I agree. This is a street car that might see the strip 1 or 2 times ever. I will do h/c/i this fall, and my overall goal is to have 450rwhp. So I think this setup will be perfectly safe for me.

I think I have decided on Michelin super sport pilot's. I'm going with the stock size tire in the back, and moving up to a 255 in the front. This will take the rev difference from 33 down to 23. Just for a little added help against potential ABS issues.

You should be more than happy with that setup. Post some pics when you get em on!!!

I mounted up a rear wheel tonight with the 1.25 in adapters.

Firstly, the I bought wheel and hub-centric adapters. They fit the hub a little looser than I would have thought, but when you tighten the lugs it seems to center the adapter nicely. The fitment from the adapter to the wheel is TIGHT. I had to lightly sand any polish the adapters to even force them on... I don't know if I like how tight they fit...

The wheel is damn close to the inner fender! How close is too close? I might have 1/2" of clearance from the wheel to the inner fender... I don't want to order tires until I know everything will fit without rubbing...

Sounds all familiar to me.

I have to kick my wheel a few times to get it off the adapter.

As for the clearance on the inner fender, I think mine ends up being closer to 1/4" after the tire is mounted. This is very close but I have never had any issues with it.

Don't mean to revive/hijack an old thread, but I just bought some C6 rims for my ws6 and adapters (coming in Friday). Did you need to trim the rear wheel studs at all? or are 1.25" adapters wide enough to ensure everything fits flush?

Quote:

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Originally Posted by Knightrider

Don't mean to revive/hijack an old thread, but I just bought some C6 rims for my ws6 and adapters (coming in Friday). Did you need to trim the rear wheel studs at all? or are 1.25" adapters wide enough to ensure everything fits flush?

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No, you won't need to trim the studs at all. I didn't end up going with this wheel setup, but I did to a trial fit.

I'm going with 18x9.5 Spyder replicas now. 40mm offset for running big brakes up front.

sounds like 1.25" spacer in the rear is the way to go, how about up front? I want to get the fronts a little more flush. Any recommendations for front spacers? I also want to lower it, have any of you also lowered the car with these wheels?? Thanks for any help.

1.5" spacer should suffice.

You will need longer studs with a spacer that size or use an adapter that has its own studs. I have 30mm (about 1.18") adapters that I don't need if anyone needs them. They are essentially brand new.

All right, how does this sound:
- Z06 wheels (18fr, 19X10rear) already have.
- Strano springs
- 1.25 hubcenttic spacers (rear may need to be adjust to get tires to snug into the wheel wells.)
- New shocks& struts.

Question- Any one know of the right part# of a shorter shock/strut to match the lower springs????
I know some people just run a stock length shock/strut but I've always heard the 'proper' way was to match springs & shocks. I've done it both ways myself and I have to agree matching was much better. If I don't match them I usually end up drastically reducing the life of the struts.Hmm, that's sounds like I'm a shock-snob. . . ;-) Either way, what works good for YOU??

Quote:

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Originally Posted by suchnsuch

All right, how does this sound:
- Z06 wheels (18fr, 19X10rear) already have.
- Strano springs
- 1.25 hubcenttic spacers (rear may need to be adjust to get tires to snug into the wheel wells.)
- New shocks& struts.

Question- Any one know of the right part# of a shorter shock/strut to match the lower springs????
I know some people just run a stock length shock/strut but I've always heard the 'proper' way was to match springs & shocks. I've done it both ways myself and I have to agree matching was much better. If I don't match them I usually end up drastically reducing the life of the struts.Hmm, that's sounds like I'm a shock-snob. . . ;-) Either way, what works good for YOU??

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You are still going to either need longer wheel studs or an adapter with its own studs for that that size of a spacer you are looking at. It's the spring rate you are supposed to match the shock because the shocks are valved for specific springs usually. Now you usually can get a way with a little bit higher or lower but not too much unless you get adjustable shocks. My suggestions would be Konis with stranos or Bilsteins (if Konis are too expensive) with a similar spring.

Thank you for the input. I'm gonna save up for the next few months and go for it. I'll post back when I get it done and let anybody know how it went and if there any mods required.

here's my 00 formula with C6 wheels no spacers.

C6 Silver Wheels
18" x 8.5" with 245/45-18
19" x 10" with 275/35-19

http://tredalign.com/formula00/famil...ls/c6oncar.JPG

did some serious clearancing of the front side of the inner fendewell.

http://tredalign.com/formula00/famil...els/c6rear.JPG