NTMD8R

As the title says...
we will be autocrossing our (new to us) 2016 Z06.

I know, I had a '14 Z51 which we didn't like... just couldn't make it work,
and we also have an '08 Z06 which we are really pleased with.

But I LOVE the C7, and I'm going to try it again.

So, staying in Street classes (SS) (which means 200 treadwear or greater),
I want to hear all your opinions about what tires are best for autocross.

Thanks

chetly

Depends on what class you want to run. But, it would require buying new wheels but the 315/335 Rival S combo will be hard to beat.

Nokones

I agree with that Chetly guy, the BFG Rivals

cpt11gs

But the 18” Rivals would not be legal in the rear for a C7, correct? Since the C7 has 20” rears, I think he would need something in a 19 or 20 to be legal for SCCA SS.

Nokones

That Chetly guy did answer the original poster's question on which 200 treadwear tire that would be best for autocrossing, which is the BFG Rival. Unfortnately, they (BFG) doesn't make a tire in a 19" or 20".

He/she could run in CAM with an 18 and be legal as hell in CAM. Anyways, CAM is where all the kool people run.

chetly

Your right, I missed that. Their only option would be the Bridgestone RE71R. Not sure what sizes they are available in for 19/20...

NTMD8R

You are correct guys.
To stay in SS, I need to stay with 19/20.

I can't go with CAM-S, because it does not include C7.

So... now you know, I have to stay with SS and 19/20 wheels.

So I guess it's Michelin PSS or PS4S..... what do you think ?

Tomswheels

C7 is now CAM-S legal for this year. Does SS allow a change to a 19” rear wheel? If so RE71R or the new Rival S 1.5 (about to be introduced) in the 305/30/19 size are the only competitive choices. If you must go 19/20 use the 285 RE71R over the Michelin, if you want to be one of the fast kids...

wtb-z

The C7 specific PSS ZP is probably not an awful tire to use, I wouldn't be surprised if it was competitive with something like a off-the-shelf P4S or Continental Sport, even if it is slower than the top flight tires.

Downsizing to a 19" rear wheel and stretching the 305/19 RE71R would be another option.

Depending on how literally your BC group uses SCCA rules, 13.3.A.1 technically should make a Cup2 C7 Z06 legal for local events.

CasualGuy

If you’re looking to be competitive, this will likely be your best option assuming that you don’t run into any ice mode issues with the stability control. A friend who is a very expeirenced and competitive autocrosser has a 2017 Z06/Z07 and had serious ice mode issues when running a 305 RE71R square setup that basically rendered the car undrivable on an autocross course. Not sure if you would run into something similar with a 2016 model.

Saddletan

Kuhmo V720 ACR for SS, a no no for CAM.

wtb-z

The V720 ACR doesn't meet all requirements for Street, so it isn't legal (except when on an Viper ACR for local events, per the same 13.3.C.1)

Saddletan

I think a Vette could run them also as long as it's not at national level. In our region a guy with a C6 was protested for the ACR tires and hasn't been docked any championship points and placed first in AS after having his tires removed for inspection.
I think the OE clause is for cars that come with PSC2 from the factory which are tw180.

DSimms77

You'd need to run a 19x12 and a 305/30R19 RE-71R in the rear. The same as what I run on my C6Z. The front would be a 285 or 305 RE-71R on the OE size 19x10. The 305 will be a pinch on a 10" wide wheel so your tire guy might have difficulty.


All the C7 Z06/GSs that ran in SS at nationals this year seemed to have that combination of 305 square or 285/305. It's not the most aesthetic setup, but it does seem to work.

Tomswheels

https://dk1xgl0d43mu1.cloudfront.net...pdf?1512080131

If anybody needs 2018 CAM rules

wtb-z

They're 200TW but they shouldn't meet the 7/32 tread depth requirements. And depending on how pedantic the protest committee is, if they're considered separate from the regular V720 line then they don't come in enough widths/diameters.

Saddletan

OK the 7/32" rule makes them illegal for a Vette. 720 ACRs are 6/32".

Saddletan

FYI a C7 zo6 in our region ran PSS 19-20s in 2016 and square 305 Re71r in 2017 and was faster by 1-2 seconds this year.

NTMD8R

Thanks you guys, for your help/info.

I will now add... I really want to just not buy any more wheels.
For my 2014 Z51 I had 3 sets of wheels, and 4 sets of tires.
For my 2008 Z06 I have 2 sets of wheels, and 2 sets of tires.

So for my 2016 Z06 I would like to just run the OEM wheels (19/20),
not have to worry about the computer going nuts over disproportionate
tires diameters...... and yet still do reasonably well in SS class.

So, based on this info... MPSS I guess ?
I've heard some guys say the Conti DW is very good too ?

Gordy M

If you want to run the Z wheels, then RE-71's are the way to go 275/19 in the front and 295/20 in the rear. They will still be a second or two faster than the Michelin's.