seattle_vette

What are people using for track tires? I just got my C6 Z51 and have been tracking with the stock tires. I had thought to go to 18 all around, but just found out that can't be done with the C6.... so I need to bite the bullet and keep 19 on the rear. Any suggestions? (This car is sooooo much fun on the track)

'06 Quicksilver Z06

You talking about the track or the drag strip?

seattle_vette

Sorry, performance driving on the track. Also, I drive the car to and from the track, and occasional daily driver.

PaBlueCoupe

Says who?

Racer C3

I know people who run 18's all around.

In my case, I replaced the factory tires when they wore out with Michellin Pilot Sports, and I do like them better than the original tires.

I use the car on the track at least once a month.

seattle_vette

I was talking to the folks at RadicalWheels, and was told that 18 inch rear wheels won't work on the C6 because the wheel offset (I think that was what he said) on this car is +79 on the rear and that would make the wheel stick out too much.

Anyway, I just ordered some Bridgestone Potenza tires from Tirerack. I mostly do lapping at Pacific Raceways in Seattle, and if anyone knows that track - it eats tires.

DANNOV

I have the Michelin Pilot Sport PS2 on my Boxster and I love them; but, if I had to do it again I would get the Michelin Pilot Sport Cup. This is a track tire that can also be used in driving to the track. TireRack has an excellant comparison test of all the Michelin Sport tires, and the Sport Cup has by far the fastest lap times.

Racer C3

I also have the Sport PS2, but will try the Sport Cup next time.

Adam 17x

I assume that you mean road course tires.

After much researching of tire brands, wheel options, internet searching, etc., I finally opted for Michelin Pilot Sport Cup tires on stock C6 rims. The sizes are 265/35/18 front, 305/30/19 rear. The diameters front and rear are each about a half inch shorter than the stock tires, thus preserving the approximately 1 inch diameter difference that I have been told the computer requires. In choosing these tires, there was a risk that they would not fit well on the stock rims given the respective rim widths are narrower than recommended by Michelin. That risk was amplified by the price of Sport Cups ($276 per front and $514 per rear). Further, I was unable to confirm that any other Forum participants had used these tires.

In short, I took the leap and the Michelins work great. I took the car (‘05 C6 z51 mn6) to Gingerman Raceway in South Haven, MI last Friday for a full day test and tune. My only other mods are DRM front brake ducts, LG spindle ducts, SS brake lines, PFC 01 race pads (front) and Motul 600. The tires (and brakes) worked flawlessly, logging over 75 laps for the day. I tripped no codes. I was to able go into Comp mode and also totally deactivate the stability management, despite the non-stock tire diameter and lack of pressure monitors in the rims. Note, I did park next to my stock tires in the pits so the car could pick up the tire monitor signal between sessions.

The tires are good for 8+ laps before they get a little greasy. The brakes never once faded. I registered a high of 1.29g on the HUD. My high mark with the stock tires was 1.15g. I addition to the extra grip, the Michelins slide progressively and are, therefore, easy to drive. My lap times were 2-3 seconds faster than with the stock tires. (Note that I never went for a full-out lap and always had a passenger in the car. I also had my Spec Racer Ford at the track, so I was able to get my “at the limit” driving in using a more appropriate tool.) After all of those laps, the Michelins were just looking scrubbed. Longevity relative to other R compound tires is reportedly a strong point of the Sport Cups. At $1,600 a set, they had better last.

My alternative to the Michelins was aftermarket 18s all around with Toyo RA-1s. The RA-1s are about $400 per set cheaper than the Michelins (solely due to the lower price for the rears). However, good wheels ranged from about $2,800 for CCWs to $4,000+ for Fikses. I purchased a very lightly used set of C6 non-polished wheels on ebay for about $400. That means it would take a minimum of six sets of cheaper Toyos to offset the price differential on the wheels (assuming that the Toyos last as long as the Michelins).

One other topic I would like to address is stock rim width. I had read on the Forum that the stock rim widths (8.5" front and 10" rear) are understated by Chevy. Well, I put a tape measure on the bare wheels that I received and can, unequivocally, say that from inner bead to inner bead, they are a hair less than 8.5" in front and exactly 10" in back. The next time I change tires, I will photograph the wheels along with the tape measure to fully debunk this myth. I had somewhat relied on the “actually wider than 8.5" and 10"” myth when gambling on the too-wide Michelins. Fortunately they fit just fine with only slight bulging of the sidewall.

I highly recommend the Sport Cups for anyone looking to track their C6 in anything short of all out competition. I also believe the Sport Cups are the only choice for drivers who want to participate in Group 1 NCCC events, as Group 1 requires the use of stock sized wheels.

I will put a similar post in the racing and autocross section.

Good luck.

seattle_vette

Thank you for your indepth and thoughtful reply. A danger of throwing a topic out on the forum is that opinions are like...umm...bellybuttons-everybody has one. Sometimes too much is confusing.

'06 Quicksilver Z06

Dude, you're rolling.

Any saftey concerns with this slight bulging? Any wear concerns with the slight bulging?

Thanks

Adam 17x

My concerns were minimized by: 1) I saw pictures of 285 and 325 Hoosiers mounted on stock C6 rims that bulged worse yet worked; 2) Frisby Performance Tire (race tire specialists) in IL said I shouldn't worry as they had mounted up more extreme mis-matches without trouble; and 3) I ran 75+ laps at high g loads with no problems, unusual wear, etc. Trust me, I wish someone made stock size R compound tires for "plain" C6s. But they don't. I the meantime, the Sport Cups work. Note that Michelin recommends 9-10" wide front rims and 10.5-11.5" rears. The C6 falls .5" short in both cases. And that's exactly how it looks once they're mounted. It's not extreme, but it's not perfect either.

TTRotary

Good information, thanks for the post. Do the sidewalls feel sloppy (i.e. do they seem to lag steering input, then take a set) or do they remain tight? I imagine compliance over uneven pavement is generally improved. Glad you got your agressions out in the FSR

Joe_G

I run Nitto 555RII's on C5 wagon wheels. I have Z51 so had to switch to the C5 brake rotors (cheap @ $24 ea. and disposable) using C5 brake abutments from Fred Beans @ $35 ea. The tires run about $1k new a set and the wheels are very cheap used. They fit fine, and I have no issues regarding pressure sensors (there are none in the wagon wheels). I drive to the track on stock wheels pulling a little trailer with track wheels and park by my stock wheels in the pits.

shurite44

I run 18's all around. Do a search on widened wheels in the tech section for an explanation. I think the thread title is Widened OEM fronts or something like that.

I did this for DR's but the application would be the same.

AU N EGL

Not going to get tossed. Most ppl who do Track days or HPDEs on road courses hang out under "General Corvette - Autocross & Road racing" fourm

When questions get asked in the wrong forum, yes you get too many wrong answers.

Mich Cup tires are great times, you will enjoy them.

Rember R compounds are measured in heat cycles, not milage. The first 3 heat cycles the grip is great, 5-10 heat cycles it drops considerabley. 12+ alomst shot, but still far better grip then street tires.

a heat cycles is EACH time the tire is used and up to opporating temps and pressures.

So driving too the track is ONE heat cycle, Three sessions on track are THREE more heat cycles

TTRotary

I am considering this setup as an interim solution for stickier street tires (I ran R2 on my 02 Z on the street and loved'em) since I have a set of Y2Ks lying around. My question to you is: which front/rear sizes did you chose? Thanks

C6dude

I got the Hoosier R6's .They are not on the car ,so I can comment on performance yet. All I can say is that the tire is very light and greatly reduces your unsprung weight. They are a sticky tire. I sent mine in for grooving for street use. rear-345's front-275,s heres some pics.

TTRotary

Damn, them -r-some meats. Are they steel belted radials or ply like the track tires?

AU N EGL

Steel is too heavy. Ply belted.

Street use?? Chit I use mine for 14-15 heat cycles ie 4 weekends on the track about 500 miles and they are shot. First 3 heat cycles are the best grip.

Here is a photo of Hooser VRL, not quite as sticky as R6s but last a bit llonger

Left Mich PS on right