Alludc

im not happy with any of the tire size choices for A Stock c5 17/18. Theres nothing decent to run on the c5 for a street tire class. stcok size wheels required, any size tire on those wheels allowed. Ideally im looking for a 295 or 305/18 rear and a 275 or 285/17 front.

HANKOOKS, SMALL 285/18 REAR even smaller 255/17 front
re-11s not even close
dunlop small 275 rear, and a so-so 265 front
kuhmo XS, big 315 rear or smallish 275 rear with good front sizes. seems as if Kuhmo to be the only option.

c4cruiser

Check out the NITTO NT05. They have the 275/40-17 and a 295/35-18

I have used the NT05 for both autocross and track days.
Having used the older Kumho MX tires, I have found that the NT05 is every bit as good if not a little stickier once you get a little heat in them. They should be the equal to the XS and might be a little cheaper. I got four 275/40-17's delivered to my house for $600 from discount tire direct. The date codes showed the tires were two months old at the time I got them.

While the NT05 has a treadwear of 200, they are pretty sticky for a street tire. But don't expect a lot of tread life and I wouldn't drive real fast in heavy rain. They are quiet and don't flat spot after setting like my old Kumho MX's would.

JiminVirginia

You could try these:

http://www.tirerack.com/tires/tires....VAN+Neova+AD08

I have a set of 295/30/18s on my Z06 for the street. Autox, I'm not sure, haven't tried, but these are excellent tires for the ST guys.

Jim

Alludc

again, a small front. havent heard or seen these on a autox yet either.

Han Solo

315 isn't really to wide for a 10-1/2" rim. make sure and watch the diameter specs while choosing though.

Alludc

AStock is 17x8.5 & 18x9.5 Han

VetteDrmr

I've run the 315/275 setup before on stock wagon wheels. Honestly it wasn't my favorite setup, as I had pretty significant corner exit understeer. Just had a hard time getting the car to rotate. 305/275 was much better. I'd guess 295/275 would be just about neutral.

I know that doesn't answer your direct question, but hopefully it's helpful.

Have a good one,
Mike

Gordy M

The Hankook R3S are a VERY good tire to autocross. I have had them for only one event and I had the fastest time of all street tire cars from AMT to THS. The closest to my time was 0.4 seconds. I ran the 255/285 set up with mid 30 tire pressure. These tire were new with less than 50 miles on them.

JD McC

I also recently looked at tire options to keep me in the street tire class (SS AT) for autoX. I have Z06 17x9.5 and 18x10.5 wheels. After looking at the options I went with NT05s 295/275s for all the reasons listed above. Just had them mounted on a set of stock Speedlines yesterday. It has been to cold and snowy here to mount them and try them out but looking forward to it.

RX7 KLR

The Hankook is a bit on the skinny side, but it is a better tire for autox than most of the other 140+ tires in the size range. The other one to consider is the Falken 615k, 275/40 front and 295/40 or 315/30 rear.

RC45

Even though the car comes stock with 9.5" and 10.5" wide wheels?

JD McC

I believe only the Z06s came with 9.5 and 10.5 stock wheels. "A Stock" includes the non-Z06 C5s.

RC45

So? Why would a stock race class penalize a stock car? Great way to reduce th enumber of entrants in your race series.

JD McC

Not sure what you mean but the stock C5 (non Z06) are in the "AS" class and the Z06s are grouped in the SS class with the C6Zs amoung others. With bigger tires/wheels and better preforming stock engines, etc on the Z06s, it keeps the stock C5s from having to compete with the Z06s. I am guessing that was the intent.
As far as tires go, in SCCA autoX, you can run any tire size that will fit on a stock size(for your particular car) wheel. In NCCC events, I think you are limited to tires no more than 10mm wider. I think I have this correct.

stevensa

I have ran the 275/315 XS on my car but mainly for RR. I did do one Auto X with them and they were pretty good (fastest street tire car there, only 4 of about 10 r-comp cars faster). The XS are worlds better than the MX from my experience. Good luck finding any XS in 275/315 in stock right now though. Also IIRC one of the NT-05 sizes is currently out also.

If I were doing AutoX mainly with stock c5 rims I would probably go for the 255/285 combo RS3. It is a great tire and the smaller sizes should make it easier to get heat into the tires in a run IMO.

RC45

So this means by under-tyring the the C5 Z06 with C5 coupe sized wheels/tyres you can bump yourself down a class and compete with C5 coupes?

vettehardt

No, because then you are not stock. You must run what size wheels came on the car.

JD McC

There is a class for cars only using street tires(AT) where C5 coupes and Z06s can compete together, as well as other cars that run street tires (tire wear 140 or higher). Thier times are sort of pro-rated against each other to help even the playing field. That is probably why the OP and I are interested in tires with a 140 or higher rating...so we can stay in this class.
Otherwise in the SS or AT categories, you could run any compound tire in the appropriate size. Just to add some confusion!

TeamZ06

You are looking at it all wrong. The 140TW street tires are not like DOT-R tires. They perform better when they are not over-wide for the rim. All the ST cars run the 255/40-17 Hankook RS-3 on 9" wheels so it is by no means too skinny for an 8.5" wheel even on the slightly heavier Vette. The RS-3 also likes some heat to perform its best so not over-sizing plays into your hand here too. You can run the RS-3 from full tread down to the wear bars for 200+ runs and have great performance the whole way through. Icing on the cake is that the 255 is inexpensive ($137 each - was $125, but TR just raised the price). If your hands and feet are smooth and controlled you will be fast.


.

Alludc

guess I didnt think of it that way Team. so 255 and 285. hard to wrap my head around running a smaller tire since for daily driving I run 265 and 295 on z rims. ill give it some thought for my next set.