Need Help with New C5 Wheels Decision

[B747VET]

Looking for some input here. My '02 C5 Vert has ZO6 calipers and
Baer drilled/slotted rotors and C5 ZO6 Factory Reproduction wheels in the C5
base sizes -17x8.5 & 18x9.5 with Michelin Pilot Sport A/S ZP's.

I want to upgrade the tires to Michelin Super Sports so figure this is the time to also
upgrade the wheels.

My plan was for C5 ZO6 Factory Reproduction 18x9.5
& 19x11 wheels and 275/35-18 & 305/30-19 Michelin SS tires and to also
lower the car 1".

Ordered and paid for all the above and then sadly found
out that Factory Reproduction has just permanently discontinued their 19x11 C5
ZO6 chrome wheels.

Now, in order to keep the C5 ZO6 wheel look, I have to either jump up to 19/20" wheels or quickly grab a set of the C5 ZO6 "Motorsport" fake rivet look 18/19's which are also due to be discontinued shortly.

So, any thoughts on the pro's & cons of those two options would be very much appreciated.

 

[Toms007]

Not sure how much that combo will set you back, but I am a fan of HRE wheels. They have or maybe had, aa wheel that looks like the C5 Z06 wheel.Big difference is they are very lightweight. Also more expensive. But I think you can get them in the sizes you want.

 

[catbert]

I like the C6 size wheels and tires for the C5. There are a number of C6 styles available with C5 offsets including the ZR1, Z06 and Grand Sport styles. The C6 repro wheels are also a lot cheaper than the most aftermarket "tuner" wheels. Just be sure to get the right offsets. Most of the tires you'd want are available in C6 sizes to fit the wheels.

 

[6 Shooter]

I went with 18's & 19's

Firestone Firehawk Wide Oval RFT: http://www.firestonecompleteautocare.com/catalog/product.action?id=72976&pricing=true
> Fronts: P245/40R18
> Rears: P285/35R19

Cray Scorpion Chrome Wheels: http://www.craywheels.com/
> http://www.tswalloywheels.com/img/scorpion_chrome_reg_large_white.jpg
> http://www.tswalloywheels.com/img/scorpion_chrome_beauty_large_white.jpg

 

[BigJimZ16]

My neighbor put the new GS repro wheels on his triple black 2000 roadster and it really looks great!! He had the chrome thin spokes on it but wanted some more rubber. He went with standard Z06 sizes.

 

[B747VET]

I appreciate everyone responding and I really do like the looks of 6 Shooters Cray wheels and might eventually consider them. However, for right now I have to stick with the C5 ZO6 wheels for a number of reasons. I have the fronts in hand, so now I need the 19/11 rears.

As I feared, a number of folks have convinced me that the 19"/20" combo would measurably decrease the handling of the car and give it a look I don't desire. I would go with an 18"/18" combo but don't need the potential computer problems that sometimes come with running same size front/rear wheels on the C5's.

So, I guess I will continue to desperately try and find two 19x11's to finish the job. If it becomes an insurmountable task I will give a serious look at both the Cray's and a C6 ZO6 solution.

Again, many thanks.

 

[Toms007]

Not sure it's the wheel diameter that is the problem. But overall diameter of tire/wheel combo. There are lots of guys (and gals) who run 18's front and rear, the important thing is keeping the appropriate ratio in overall diameter close to stock.

A stock front tire of a C5 is 245/45 x 17 245 is the width of the tire. 45 is the ratio of sidewall height compared to the tread width. 17" is the wheel diameter (431.8 mm). To figure the diameter of the tire you take wheel size 431.8 (17") and add that to sidewall height 110.25 (figured by 245 x .45) x 2 (for top/bottom sidewalls) 220.5 = 652.3/25.4 (mm/inch) and you come out with 25.68"

The rear tire figures the same way. 275/40 x 18 275 x.40 = 110. 110 x 2 = 220 18 x 25.4 = 457.2. 457.2 + 220 = 677.2 677.2/25.4 = 26.66

So the rear tires of the Corvette are (roughly) 1" taller than the fronts

Likewise on the Z06 cars the fronts are 25.3" tall, the rears 26.1" tall. Again approximately 1" difference.

If you retain this 1" diameter difference the computers on-board won't be an issue.

you could run 265/35 x 18 fronts and 295/35 x 18 rears and keep the same ratio (even the same diameters as stock)

 

[B747VET]

I was wondering about that same possible solution just last night. Thanks for explaining it so well.

Certainly worth considering. But that 19x11 lets me go to 305/30. Decisions, decisions..

Many thanks...

 

[Toms007]

285/35 would be short, better off going 285/40

 

[B747VET]

285/35 would be short, better off going 285/40

Thanks again. I agree that would provide a nice safety buffer. Apparently there is no rhyme or reason as to why one C5 never has a problem with 18/18 and then the next setup done on a different C5 with the same wheels gets constant messages.

 

[dougelam]

Before I bought my new wheels I put my rears on the front to test for fit and clearance and found that they rubbed, in order to put a wider wheel on the front wouldn't we need a different offset?
That offset would be the same on the outside and the tire would be inside the wheel well deeper. With the tire being the same diameter I did not see much difference, so I decided to stay with the 17/18.

Would more positive caster have eliminated the rubbing??

 

[Toms007]

Doug, that is a possibility. I really don't know what the offsets are on the standard C5. And I don't know enough about alignment procedures to comment yea or nay on the camber issue. I do know that C5 Z06's had 17 x 9.5 wheels in the front, so as long as the offsets were the same I would think that the rear 18 x 9.5's should fit without rubbing.

 

[B747VET]

I wanted to say thanks very much for all the time folks spent responding on these issues. For a variety of reasons I decided to stick with the C5 ZO6 look. We found the 18x9.5 chromes for the front. There are no more chrome 19x11 rears being made but we have bought two black finish 19x11 rears that will be stripped and chromed. The only drawback is that these wheels are so heavy.

Thanks again.