EA-sports

It's time for new tires for my EB Z06. What's the consensus on the current best autocross/track day tires in standard Speedline 17 in the front and 18 in the rear wheel size? The car is not driven daily and I drive it for less than 1,500 miles annually so tire wear is not really an issue. When I bought the car I got 2 sets of Speedline wheels so theoretically I can use all 4 rears if that's better. I'll probably run in AStreet for Scca autocross.

Also, what's the good alignment for autocross and track days? Thanks guys.

insertclevername

Since you have 4 18" go that route. 275/35 front 295, 305/35 rear.

If you can wait til next month to see what new sizes release, will be good, if able. Supposedly some new sizes will be released for some good tires.

FASTFATBOY

I would run the 4 eighteens as you can rotate tires to get more tire life if you run a square setup.

Do a Google for "Pfadt C5 Corvette Alignment Specs" and save the PDF. I have it but don't know what to do with a PDF to post it.

You will have to look up the rules for that SCCA class. Is it a 200 tread wear tire max?

I can tell you this, I had -1.3 front and -.9 rear camber on race takeoff slicks and corded the outsides in 6.5 track sessions. Not near enough camber, I since went to -2.2 and -1.3 to see if it will solve the issue. Stock suspension bushings and bars don't do much to help keep camber under the car on good tires if you drive hard.

69autoXr

Can't run four rears in A-street. You have to keep the front wheels 9.5" wide.

EA-sports

Bummer no all rears to run in A-street. I'm also limited to 200tw but I can wait in case more brand come out in my size. So what's good 200tw tires, BFG Rival-S?

aaronc7

255/40/17 and 275/35/18 -- RE71R maybe?

You'll find not many great options in ideal sizes on the stock C5Z wheels.

jesup16

RE71R's were the 200tw tire of choice in 2015. BFG RivalS were probably the 2nd best tire.

Since RE71R's aren't made in sizes specific to the c5 z06, a popular combination was RE71R's up front and BFG RivalS in the rear to fit as much tire as possible.

As previously stated, there are rumors of new sizes of the RE71R making their way to the US in the very near future.

Since you don't know some of the basic SCCA rules regarding wheel/tires sizes, I'm going to guess you are new to autocross. In those regards I'd say buy a set of the BFG RivalS or Hankook RS3's and spend the life of those tires learning.

EA-sports

So RE71R > RivalS but wears out faster and not always available in stock C5Z06 sizes? Got it. I guess I can wait to see if Bridgestone actually brings new sizes for the RE71R or not. I used to autocross NA Miata with local non-SCCA club so I'm more familiar with the R1R non-200tw debacle and not too familiar with SCCA rules lol. Are the RivalS and RS3's available in stock C5Z06 sizes? Thanks..

jesup16

I wouldn't say the RE71R's wear out faster. I got 100 runs out of mine and there's plenty of tread depth left. I bet they will cycle out before they wear out. I also drove to and from all the events on them. Most drives for me were 30-60 minutes. And you can sprinkle in a few weekend joy rides and trips to the shop.

You'll want to do some homework on tirerack.com and other A-Street builds. Since 17's no longer come in sizes 255+, most A-street competitors in C5Z's used a C5 rear wheel (18x9.5) up front to get wider 18" tire sizes.

From what I've seen, RE71R's probably won't come in much larger than a 295 for 2016. RivalS can be had up to 335's for rears.

I would think this would be ideal for RivalS:
Front (c5 rear wheel) 18x9.5 with 275/35/18. You can sub the RE71R here today.
Rear (c5z stock wheel) 18x10.5 with 315/30/18.

I just looked on tirerack.com and R-S3's are only available up to 275 width now, so I would nix them from the conversation.

0Luke@tirerack

Here is a complete list of the Potenza RE71r available sizes including the new additions for 2016

195/50R15
205/50R15
195/55R16
205/45R16
205/50R16
205/55R16
225/50R16
205/45R17
215/45R17
225/45R17
235/45R17
245/40R17
245/45R17
255/40R17
215/40R18
215/45R18
225/40R18
225/45R18
225/50R18
235/40R18
235/45R18
245/40R18
245/45R18
255/35R18
255/40R18
265/35R18
265/45R18
275/35R18
285/30R18
225/35R19
235/35R19
235/40R19
245/35R19
245/40R19
255/35R19
265/35R19
265/40R19
275/35R19
285/35R19
245/35R20

rigit

pick you up a set of base rears (18x9.5) and run BFG rival S. 275/35-18 in front and 315/30-18 in the rear. that is the winning combo for A street.

If you have to rock your OEM fronts, then its 255/40-17 rival S in front.

can,t rock the Z rears square, not legal, have to run 9.5 up front. However, if you want to run CAM-S then rock square with 315's.

JLZ06TR

So no 305/30R19?

0Luke@tirerack

not yet ....

insertclevername

How about Dunlop ZII star spec? Are they going to add new sizes?

EA-sports

I think I can run my C5 Z06 with whatever size 200tw tires in CAM-S this year right?

firebirdfan

When is the 285/30R18 able to be ordered? I've been checking just about every day for them and haven't seen them yet.

Any news on new Rival S sizes?

JRL

How about 285/35/20's?

EA-sports

All else equal which one is better, 285 wide RE-71R or 315 wide Rival S? On square 18in C5 Z06 rear wheels for mainly autocross and may be a track day or two (less than 1,500 miles/yr).

woody6244

Do you have specs on the 285/30R18 I can find them on tire rack.

Cashmo

Dates for the new 2016 RE-71R sizes as seen elsewhere.

Size Date
265/45R18 3/1
235/45R18 3/1
245/35R20 3/1
235/40R19 3/1
265/40R19 3/1
195/50R15 3/1
285/30R18 3/1
255/40R20 8/1
295/30R20 8/1
285/35R20 8/1
305/30R19 8/1