sd7ss

What do you think the C7 Z51's chances are in SCCA AutoX for 2014?
Solo Events Board apparently leaning toward classing it as Super Street. Right there with the C6 ZR1, various Loti, and so on.

autoxer6

I think the car will hold it's own as long as you can fit some Rivals on there. I haven't looked at tire sizes. The pilot super sport is a great tire, but they just wont compete with the Rivals.

I'm pretty excited to see if the e-diff will understand the parameters of autocross. It has great potential to make the C7 a really drive-able autocross car. The diff should go open on corner entry then tighten up as you get to the gas. The question is with high steering angle inputs, and high yaw rates unique to autocross, the electronics may not lock the diff like I would want on corner exit because it may think a spin is about to happen. If it does lock up hard, then this could be the best big HP car in a hairpin.

Solofast

I think it also might depend on how you drive, or can adapt your driving to what the car wants. I like the diff to be tight when I'm doing deep trail braking, and if the computer can understand that's what's going on it'll be great. More likely, the driver may have to adapt his style to match that of the folks who programmed the thing or it could slow you down.

talon95

I don't see why it wouldn't be in A-street with the C5/C6. The C7Z51 will likely not be faster with the narrow 8.5" front wheels. I'll be a little surprised if any C7 is significantly faster.

Dave G.

TripleAstyle123

SCCA has c5Zo6's and all C6's classed in SS. I don't see why they wouldn't put the new Vette in SS also.

TripleAstyle123

I bet the electronic differential on the Z-51 will make it much faster out of corners due to less wheelspin with more power applied to the wheel with traction. ( I believe that's what the E-diff does)

Solofast

He's talking about next years new "street" tire classes, where the C5Z will be in "A".

sd7ss

What got my interest up was the story about Jim Melo driving a C-6Z at VIR for a test last year. They allegedly drove over a second faster around VIR on the C-7 Z-51 wheels and tires instead of the stock C-6Z wheels/tires. Sounds a little too good to be true.

Anybody know more? If true, the C-7 Z-51 might be a contender in Super Street for 2014.

Only real downer for AutoX is the C-7s longer wheelbase.

vettehardt

I sat in on a Michilin seminar at our NCCC convention this year. Chevy went to Michilin and said they wanted equal or better performance than the current grand sport in a smaller wheel package. Michilin was able to deliver. The tire compound is just that much better than the current wider GS tires.

I believe wherever the C6 grand sport is being classed is where the C7 Z51 should be. It should be slightly better than the GS. I don't know SCCA classes that well, but in our September NCCC meeting we should decide where to stick the C7. So i believe it should go in the M class for autocrossing with the GS and the Z06.

sd7ss

That's what I was thinking. (Only on street tires, that is!) So when I saw somewhere that the SEB was considering the C-7 for Super Street, I wasn't too surprised. They can't really assign the C-7 until 1,000 are on the ground. Now that production has started, that shouldn't take too long.

At the moment, I don't see a Rival or a D2 that fits both front and rear well. At least one will have the option of fitting the base or the Z-51 OEM diameters, I suppose.

I so want to get back into a Corvette, after doing penance in a Pony car for several years. Something to look forward to, perhaps....

sd7ss

Production numbers are fast approaching 600 as of Sep 9. Should be about time for the SEB to drop the C-7 into a "street class" for 2014.

RC000E

I personally talked to Jim about this. Jim didn't believe the new C7 Michelins could perform beyond what the outgoing C6 GS had, due to the large reduction in width. So, he lapped VIR in a stock GS, then they put on a wheel/tire package with the new C7 tires and he lapped 1 sec faster on the new tires.

RC000E

C7 has a smaller turning radius, and with the e-diff....fuggetaboutit...gonna crush C6's at the autox.

autoxer6

Why would turning radius matter? I have never reached full lock at an autocross.

The new tires dont really matter much either since there are other faster 200 TW street tires than the PSS.

sd7ss

This remains to be seen, and in fact is one of the reasons I started this thread. The Michelin Pilot Super Sport ZP (run flat) that was developed to meet a tire spec criteria (TPC 1431) for the C-7 Z-51 might just help the C-7 to be a ringer in whatever "street" class the C-7 winds up in for 2014.

Anybody know if that "1431" TPC is anything special or different from other (previous) PSS ZP applications? It's got the same 300 TW on the sidewall as the previous PSS tires have.

talon95

I still think the C6Z/C6GS will be the best choice for A-street (Until the C7Z/GS/etc... at least). On 200TW tires, it's going to be hard to beat a 335 on a 12" wheel. The 200TW tires just don't put power down well at all compared to an A6.

Dave G.

racebum

that michelin SS is a utqg300 tire. i'm picking some up this monday to see what the hub bub is about. lot of chatter that they are competitive with 200 tires

sd7ss

I agree, Dave. The catch is, if the C-7 winds up in Super Street vs. A Street; it won't be competing against the GS or the Z06.

August 2013 FasTrack Draft Minutes:
"The SAC and the SEB are monitoring Corvette C7 news and information. A classing decision will most likely come in the 4th
quarter of 2013. Preliminary information suggests this car will be classed in Super Street."

Two important points that caught my interest originally were the Melo at VIR story about the C-7 wheel /tire package beating the OEM stuff on a GS, and the reference in some old SEB minutes about the SEB "leaning" towards putting the C-7 in Super Street. (away from the GS and Z06 in A Street).

Just surmising the C-7 might have a chance in Super Street with the OEM tires. I'm skeptical, but keeping an open mind.

Obviously we're not going to resolve this speculation until we see the C-7 classed by the SEB; and see the car at an auto-x. C-7 production just went by 800, and going about 60/80 a day. Shouldn't be too much longer.

John

Cashmo

To be clear, the SAC/SEB can class a new car at any time, it doesn't have to wait for 1000 units to be built or sold. The SAC meets Tuesday night and will probably send up a recommendation to the SEB then.

While the C7 has narrower wheels and a longer wheelbase than it's predecessors, it has a better weight bias. The diff and OEM tires are question marks as to it's ultimate Street autox performance. Super Stock (R comps) classing is a no brainer but Super Street vs A-Street is a lot more cloudy. It's going to be a tough decision but one that we can always change with the 12 month rule.

6SPEEDZ

I don't know how it compares at auto cross. But I have drove the new C7 on track and it is stock tire to stock tire better than a C6Z. That said I have Michelin Super Sports on my C5Z and they are an incredible tire for the tread wear. Yes the C7 does have a good improvement over the C5/C6. It's easier to drive and even the standard seats are a way better than the C5/C6 seats.