C6Brain

I have been trying to find R-compound tires (for HPDE) in stock C6 corvette wheel sizes. The closest I can find are the Hoosier R6 and Toyo R888, with front wheel matching, but the closest rears available only in 295/30/19. This translates into a 1/2" difference diameter and 3% difference in circumference over the stock 285/35/19. The Hoosier tire rep I spoke with advised me not to buy his tires, as according to a GM engineer he spoke with, the traction control would activate since the car would sense that the rear wheels were spinning. I have seen threads on the forum suggesting that the use of a handheld programmer would allow one to dial in their tire size. Since I have a supercharger installed by Lingenfelter, I contacted them and was told that any entry into the PCM would reset the settings back to factory default mode. Having said all that, here is my question- will turning the traction control off or into competition mode allow me to run the R-comp tires in this size?

Craigster05

You have nothing to worry about. You just got information that is not accurate.

You can run the Toyos fine. Here's proof: http://forums.corvetteforum.com/show....php?t=1985383

The Hoosier rep is lying, he wants you to buy Hoosiers. I won't get into too much tech detail, but he does not know what he is talking about. There are plenty of guys that swap 19's for 18 Drag Radials, widened wheels, etc. There is a tolerence built into the computer, and even if it were a huge size difference (1/2" is nothing), you could change the size in the computer....and changing the tire size entry DOES NOT reset the computer back to factory default mode.

There's plenty of guys running them with no problems. They impressed me so much, Ive got a set coming for my own car.

EvilBoffin

Keep in mind that Hoosier just brought out a 315/30/19 size in both R6 & A6 tires. That should work well when matched up with the 285/18 in front (or even the 295, if it doesn't rub when mounted on your particular wheel/alignment setup), because the 315 is 26.1" tall.

Here's the info on the Hoosier site :

315/30/19 R6

C6Brain

Thanks for the info.
The Hoosier link you provided suggests wheel width at 11-12", which is wider than the stock C6 10" width.

EvilBoffin

Admittedly - the 10" stock C6 wheels are not optimal for this size tire. However, it SHOULD WORK ANYWAY. These 'recommended wheel sizes' assume that you can afford to buy a set of wheels specific to a particular tire size, or that you compete in a class that allows you to optimize your wheel sizes.

Consider this -

For years, the top SCCA B-Stock National Championship Mazda RX-8's have routinely run 285/30/18 Hoosiers on EIGHT-inch wide wheels (!!). So do Solstice's. Same for Boxster S's with 7.5" rims. And many Miatas with a maximum SEVEN-inch wheel successfully run 245's.

In stock classes, you run what WORKS and is available while using stock wheel sizes... not necessarily what the manufacturer suggests.

If all else fails, you can always get a set of four 18x10.5 OEM C5Z06 rear wheels for your C6. As long as you add enough negative camber in the front (which you need anyway for proper track handling and even tire wear), it should not rub. Forum vendor House of Wheels has new sets of these for about $880.00 total shipped right now. They are light, strong and well-made (by Speedline). Then you can run 285/315's or even 315's on all four corners (referred to as a 'square' setup). Another advantage of such a setup is that 18-inch tires cost less then 19's.

I will leave this disclaimer - This 315/19 is a brand-new size Hoosier, opinions here are never consistent and YMMV... So consider this just another suggested option for your consideration

C6 4 AL

I have them on my 07 C6, they work great. No problem with traction control, took to Streets of Willow they are awesome. I would recommend them to all C6 owners. They even work well in the wet!

C6Brain

are you using stock wheels?
which tire sizes are you using?

WBHighwind

Will a 315 R6 fit on a 9.5" rim?

C6Brain

the recommended rim is 11-12" for the 315 R6, according to the Hoosier website

John Shiels

mount on there? Yes with a lot of cursing! Work properly no!

Ben Diss

Traction control compares the front and rear wheel speeds to detect slip. By using a smaller rear tire you the margin of difference will be smaller. The result is that at some speed you will get a traction control activation. I'm running 1/2" smaller rear tires and for me it happens at 108 MPH.

- You cannot fix this in the tune

- Engaging Competetion mode or turning Traction Control off fixes this.

By the tire you want and don't worry about the size being off just a little bit.

BQuicksilver

fastmtws

I bought a used set of OEM c6 wheels and was wondering what the best size hoosier a6 tire to put on. For front either 245/40 or 275/35 or even 285/30 for rears either 295/30 or will even a 315/30. Car is bone stock and and I like to tear it it up aliitle on short autocross track. Will any of these combos work without rubbing or special alignment? TIA By the way anybody have any used ones in these sizes?