Have you used the 275 before too, how does it compare?

I have not on the C6GS, but did on the rear of BS C5FRC and honestly don’t think contact patch is much different on a 9.5” wheel though as the 285 is squeezed.

If you're not opposed to running different brands, run the 71R's on the front with the 335 Rivals on the back. That worked better then the 275 Rivals and would still allow you to run the wider rears. Temps were 35ºF when I compared both setups though.

Not sure what your location is. If you were a local, I'd let you try that combo.

I've considered that too, it's tempting. Running looser tires in the rear hasn't worked great for me in the past. Although these would behave more similar. I've been reading about how differently they behave. Re71r grip right away and fall off as they get too hot. Real hot in South Florida. Then the rivals need to heat up for optimum performance. They seem to behave oposite. It's probably too Minor to really matter but that has me on the fence on which direction to go. Re71,rival,or combo. Down here we run in groups of 3-4 runs at a time with about 10 min between runs in the morning and again in the afternoon. Even though it's hot I'm leaning towards the re71 285/305 to start and maybe try something else the following year. I don't think they will get too hot and greasy with those limited runs.

The 335 Rivals wont be loose on the rear paired with the 71R’s on the front. It still had an understeering bias even in the cold. The Rivals are to the point where the wear bars are almost gone compared to like 80% new 71R’s

Managing hot tires is easier than cold tires. You can get a water sprayer and spray your tires between runs if they get to hot.

I’m considering trying that setup myself this summer as I picked up some used 335s.

Results from my first Pro Solo this past weekend, only Vette faster on the right side course was Vivek by .3 Had a .499 redlight on the left side, then the asphalt course got greasy in the hotter afternoon and the next morning it was wet for the final heat. Had the fastest 2.1 60’ out of the Vette’s with my Grand Sport and wasn’t doing a burnout even though it’s allowed before the run. Temps were ~80, 90 and 70 for the respective heats, hope that helps. Porsche’s with their launch control and PDK we’re cutting 2.0 60’s
https://cimg7.ibsrv.net/gimg/www.cor...fc70db5830.png

What he said!

... Unless you are in very hot temps and can handle the vague feeling of the Rivals. If you are trying to be ultra competitive the Rival S is the way to go in hot temps but will not "switch on" quick enough in cool temps. I use RE71 in spring, switch to Rival in mid summer, then back to RE71 in fall. I like the feel of RE71 much better, they inspire more confidence, but in very hot temps they get over heated and greasy after a run or two.

If you have the money/space for 2 sets of track tires, this is the way to go.

So, what a lot of folks don't know is that the Rival 1.5, while the same compound as the 1.0 is a very different construction and what was maybe the "right" deal before for setup may not be now. Made more complex by the fact the old one was pretty good out of the box, the new one takes a lot more heat cycling to get good, kind of like the RE71R. So beware. And I stay on top of this stuff pretty well. Also there is the new Yokohama which seems to hold some promise too, though not seen them much on any big car, but what they are doing on smaller cars is typically what we want (like better power down) in the higher HP RWD stuff.

Just did a test and tune with a STS Miata prepping for nationals. They tested RE71, Rival S 1.5, AD08R and A052. Ambient temp was mid 90’s and track temp was 120+.

In order of fastest to slowest for multiple drivers.
A052
Rival S 1.5
RE71R
AD08R

The A052’s ran consistent times 5 runs in a row, tread temp reached 160 with no dropoff in lap times. The tread didn’t get gummy or melted like the way Rivals/RE71R’s do at 140. They also commented that launching at 5K with Rivals would spin them, but they needed to launch at 6K with the A052’s, since they hooked that much better on launch.

They look really good and I want to try the 295/30-18 on my fronts when my 315 Rivals wear out.

What was the Delta if you don’t mind sharing?

Rode in last year’s BS national champion 1M initial test run on the Yokos at the last local event and was impressed, he just won the Topeka Pro Solo on them so they seem to be working.

The 2 fastest drivers were .2 secs faster with the A052 than with the Rival S 1.5 on a roughly 28 second course. It was a shorter course since it was geared more for car setup to remove/minimize as much driver error as possible.

Also, the Rival S 1.5 were 225 and the others (71R, A052, AD08R’s) were 205.

As you can see tires are/were sticker and not worn out. AD08R’s werent originally part of the test, a Civic driver offered them up for comparison.
Attachment 48347215

So the best fastest Corvette tire is the bfg rivals...

I think more testing of A052 needs to happen first to see if they do better than the rivals in hot and cold before making that statement, but in the heat it may be splitting hairs between 275/335 Rivals, 265/315 A052s and 285/305 RE71Rs. Could be reverse order when cold though, I didn’t like the mixing 285 RE71Rs and 335 Rivals at last event fwiw.

Do they come in Corvette sizes? 275-315 and 325-345

315’s are the widest they come in. I’ve got 10.5” front wheels so the 295 is the perfect fit for it, so I should gain some better front end feel by not having pinched tires.

The fastest time the Rivals ran on the STS Miata was a 28.1xx which came on lap 3 I believe. The very first lap on the A052 was a 28.1xx, keep in mind if was the first first time the driver used the A052. By the third lap, he ran a 27.9xx. He was within .1 sec for laps 4/5. We checked tire temps and it was 160F. We sprayed the tires and the codriver took it out for 5 laps and beat his fastest Rival time by .2 and all 5 laps where consistent. Tires looked amazing in terms of wear at 160F. I can see why the A052’s are banned for CAMS.

What was the issue? I have that combo and love them. Only done 2 AutoX so far but 4 more coming up before end of August.

:cheers:
DH

Yeah, the 295s are 11” wide tread width.
I didn’t know they were banned from CAM-S???

It was a low grip surface and wasn’t necessarily horrible just not as precise, but definitely more tail happy for the first bit of each run till the rears got some heat in them as I didn’t have a co-driver and we have large heats in Texas with 167 total entries.