muir.

Would like some opinions on this topic - this is for a C6Z that is essentially only being used for track days at this point, has pfadt single adj coilovers, pfadt sways, poly bushings, skf race bearings, solid rotors + XP12/10 pads, but still runs street tires (Michelin Pilot Super Sport on stock rims - 18" front, 19" rear).

I feel at the point where I'm comfortable driving at the limit of said street tires traction and am looking for the next step. I was extremely happy with the stopping power of the XP12/10 combination and could feel them clearly overpowering the tires (albeit in a controllable fashion) throughout the last event. I want that next level of stopping and cornering power and it seems tires are next.

I notice a LOT of people running Toyo R888s, though typically on lighter vehicles. Commentary around the web seems to be mixed, some folk seem unhappy with longevity through multiple heatcycles.

I've read a lot about Nitto's NT01s and there is a lot of positive commentary out there on these, however they seem not to be made in suitably large sizes for the rear of a C6Z? (Is this true?)

Hoosier R6 (R7s now?) seem to also be very popular, though I've read this is another rung up the ladder again and could present a rude awakening for someone only familiar with street tires.

The last question is, do I stick with stock rim sizes for now and find the next level tire that fits, or do I jump to 18x11 and 18x13 rims sooner rather than later?

Car is trailered to the track because I'm paranoid about breaking something and being stranded, and I essentially do not drive it at all on the street anymore. I am planning to put a cage & appropriate seat/harness in the car when I can find a reputable cage builder in the area (Greater Sacramento.)

Any/all thoughts are appreciated.

StreetSpeed

If you're trailering, I'd bite the bullet and go with 18s all around. Cheaper, more readily available tires and a larger selection.

I would recommend either the R888 or NT01 before you jump to the Hoosiers. The Hoosiers have way more grip and a lot less warning than the aforementioned tires. Also 16 cycles on an R7 is about the tire's useful life in my opinion. So $1500 (or so) divided by 4 days of driving = $375 per day in tires. If you can afford them, Hoosiers are way faster than the other options.

I'm now using Hoosiers for racing and qualifying and Conti scrubs for everything else. However I might change to just buying fresh R7s and using only new ones for racing. Every time I put on the scrubs I'm disappointed to not be running the Hoosiers. Even "fresh" scrubs seem to be an easy 2-3 seconds per lap slower than my 8 cycle R7s. But for $100-150 per tire you can't beat the price.

As always, YMMV.

63Corvette

If your goal is to get more seat time for your money, then I recommend 18" scrub slicks from GT Racing tire....who are a Forum vendor.

JeremyGSU

Eventually, I would recommend this. But if you've never driven with anything above a street tire I would learn to max out R-comps first. The slicks mentioned give zero feedback before breaking and you really need to know the limits of your car before jumping to those IMO.

I think either the NT-01's or the 888's would be a good choice.

0Anthony @ LGMotorsports

I agree too....far to many other things to take into account with a real race tire.

Given they are still "good" they have the capability to generate 2 times what your street tires do. That being said it is going to put more wear on suspension components, oil system, wheel bearings, brakes.....

Also depending on the tire they are going to fall off quicker and when they are cold...like driving on wet pavement.

For a C6Z on slicks you need better bearings, better calipers, camber/caster kit, and a full upgrade to the oil system if you want to keep the car alive for any length of time and can push it on the tires.

I do not see any reason not to go to 18" wheels and throw some Hoosiers on it though. Stick with the R's..not the A's and you should get some good time out of them. They do fall off quickly when they are done so keep notes.

Still a good idea on bearings a a camber kit with these as well.

TorontoC6

Get some 18"s and start with R7's. You can also buy scrubs cheap.

brkntrxn

Go to 18" wheels and buy a set of square 315 NT01s. You'll get 50+ heat cycles out of them before they fall off, if you don't cord them before then.

muir.

Speaking with Todd at GT racing tire today, he indicated that 18" is not a must anymore due to so many cars running 19" rears nowadays vs 3-4 years ago... So current thinking is stick with stock rims and try a harder compound (Continental G5000) scrub slick in 285/645/18 and 325/710/19. The R888 is also available in this size, however at 3x the price... It is more than tempting to try the continental tire... So i guess it is down to R888 vs scrub continental slick at this point.

As noted, I do have SKF bearings, pfadt camber kit (+ other bits) on this car. The point about oil system upgrade is something I'll definitely have to consider.

skxf430

You can buy the discontinued Conti slick for about $850 shipped. These are new tires but have been discontinued by Hoosier as they went to a slightly different compound.

Bill Dearborn

There is a time to transition from street tires to R compounds. I don't feel there is all that much difference going from street to R888s or street to Hoosiers. Yes, the Hoosiers will grip more but the changes in handling at the limit of each tire isn't all that much different. If you are very experienced tracking on street tires you should be able to handle the transition to stickier tires.

However, I am one of those guys who started doing track events with R compound tires from the first day. I switch between R compound, slick, street, R888s depending on the condition of my tires and when I want to pop for another set of tires. I have even run street tires on the front and R compound tires on the rear for a few track days.

I purchased some Conti slicks from Todd at GT Racing tires in 13 and ran them for 6 or 7 track days in 13 and another 8 track days in 14. I corded the two front tires on the last day and they were so slippery it was like driving on ice before I stopped because of the cording. I could have probably thrown on my street PS2 ZPs and knocked seconds off my time.

Biggest problem with the slicks was getting them up to operating temp/pressure with the stock TPMS working. The low cold starting pressures made it hard to get the car up to speed (especially on cold days) until I disabled the TPMS.

Bill

C5 Hardtop

As already stated and worth mentioning again because its urgent, moving to a stickier tire is going to take more than a good tire and rim choice. Most importantly and depending on the track, you could blow the engine from oil starvation during a high G turn (generally long sweepers).
I don't know what the solution is, but this huge step to an R compound is one reason why I ran street tires. I wanted to retain the factory warranty. From reading posts here, I think scrapping the GM 'dry sump' system and going with an aftermarket dry sump system (several grand) is the way to go. But Lou or someone from LG Motorsports would know how to address that.

muir.

I'd be very happy to get that kind of usage out of a set of tires (10+ days), that would last me a year which is fine.

What's the issue with the TPMS and low pressures?

My location is such that I need 4WD to get out of the driveway in the winter!... I have only been driving during high temp summer days thus far, e.g., mid 90s+ at Thunderhill. Rain and cold seems easy to avoid out west these days... :\

flash911

Side note - Mike Tolle / Tolle Fab is in Rancho Cordova. The man gets a from me.

StreetSpeed

How does one do that? I'll pick up a set for $850 if so.

Edit: I guess this is it - https://www.hoosiertire.com/discontinuedtires.htm - but I see nothing that would work on the front of my car.

skxf430

Their inventory changes quickly, and it looks like they sold out of the smaller sizes. I got lucky and scored a set just in time.