NTMD8R

I have been going through the 2015 SCCA rules.

In Class SS (where the C7 is mentioned), it SPECIFICALLY states that the Z06 OEM tires are NOT compliant for this class.

But for SSR (where treadwear is not a consideration), it does not mention C7 at all.

Actually I have a C7 Z51 (which would be SS), but I am increasing the wheel sizes and going with R888, so I am looking at where it would next fit.
I expect SSR.... allowing for Z06 sized wheels and unlimited treadwear,
this is where it would fit.

Anyone in the know?

FAUEE

It will probably be in the same class as the C6 ZR1. Which is to say, explicitly excluded from a stock class. So you're looking at SP or SM I'd think.

69autoXr

C7 Stingray is listed as eligible for SSR (2015 Solo Rules Appendix A, page 175).

However, you are limited to stock-sized wheels for SSR. If you put C7Z06 wheels on your C7 Z51, you'll be in SSP, no matter what tires are mounted on them.

As for your title question, the C7 Z06 is eligible for SS (App A page 163), however as you noted the OE tires are not compliant. These are National rules, your local region may allow otherwise.

NTMD8R

I would agree... my question comes from thinking that I could use "Corvette" wheels on my Z51
(as in Z06 wheels).
They only mention C7 in SS and SSR.

Oh well, in my case, I really don't care what class I am in...
I just don't want to be accused of being in the wrong class.

69autoXr

It doesn't work work like that, in SSR they have to be same size as standard for the model and option package, with +/-1/4" offset allowance. C7 Stingray and C7 Z06 are not the same and can't interchange wheel sizes.

http://scca.cdn.racersites.com/prod/...ses_online.pdf

In red, page 163 Super Street Class "Corvette Z06 (OE tires are not
compliant) (2015)" just under "Corvette Stingray C7 (2014-15)".

I agree no mention of C7 Z06 in SSR.

ImpatientlyWaiting

Can I ask a dumb question?

I've never been to an SCCA event but I am waiting on a C7 Z06 convertible without the Z07 package. Are both sets of tires excluded or is it just the 2's and does not being compliant mean I can still drive or does it just impact which class I'm in?

talon95

Only the PSC2's are illegal in street class. You could run the vanilla PSC2's in SSP, although the Z07 tire isn't quite the same (tailored specifically for the C7Z) so it may not even be legal there.

Unless I'm mistaken, the non-Z07 comes with standard Super Sports with 300 TW, right?? If so, those are legal in street.

Xian

Construction differences within a specific type of tire aren't illegal/addressed per the rules so all PSC2's are treated the same. As such, I don't see why he couldn't run in SSP or SSM with them if he wanted. Heck, for a novice/local I doubt most folks would care if he ran Street/stock despite the "illegal" tires.

talon95

You may be right about the rules technically allowing it, but given all the hubbub over the 195 Toyo that even looked identical to the rest of the sizes, I suspect someone would take issue with running them and would not be surprised if they were ruled against. Section 13.3.B.4 alludes to this. Although that section is talking about the entire model being changed, it suggests a tire with significant compound and/or tread design is considered a new/different tire.

That said, I do agree all of this is pretty much irrelevant in regards to running regional events. I wouldn't care if someone ran them even in street myself. Certainly no issue for SSP.

ImpatientlyWaiting

Will I be allowed to run though? I don't care what class I'm in, I just want to be able to throw my car around a little bit.

troyguitar

You can always run in some class or another as long as you meet safety tech (and sound requirements at some sites). The PSC2 tires will put you in SSP, the PSS tires put you in SS.

For the OP: If you change the width of your wheels, you get bumped past SSR up to SSP.

ImpatientlyWaiting

Ok cool thanks. I'm assuming a convertible C7 Z06 with no mods meets safety requirements?

Awesome, was worried I wouldn't be able to flog it around at all without a roll cage

troyguitar

For autocross you don't need roll bars, for track days you do. (generally, there are probably exceptions to both somewhere)

NTMD8R

But... SSP explicitly does NOT mention C7 vehicles.
So, therefore I expect I will now have to go to SSM.
Which is fine... I just want to make sure I am in the right class.

troyguitar

SSP has the "Sports cars over 2.0L not otherwise classified" line at the end which should cover the C7 and C7Z.

NTMD8R

Aha.... right you are. So SSP it will be.

dhowdy

From the rulebook

Of course that's in direct conflict with the car's classing in Appendix A

So uhh... the OE tires are legal except when they say they aren't...

Pick a class that's reasonably close to what you should be running it, and unless you start winning, no one will care.

RxCritical

We had one run in a regional autocross about a month ago. We let it in SS as that is where SSCA classed it. We took the stance that the standard tires with a treadwear of 300 were ok in SS but if it had the optional 180 TW tires then those were the ones that the rules call non compliant with SS. Maybe next year after some data they will reclassify the ZO6 into some other class.

C7_Z06

This is correct, my C7 Z06 with the stock Michelin PSS tires gets classed in SS. I have done the same class in two different autox event organizers. the Z07's Cup 2 tires are not allowed in SS class.

GTB/ZR-1

So, anyone know if there's an exclusion for the Z07--but on 200TW tires?