Lawdogg

Has anyone put the new Mich Super Sport tire on their ZR1? If so, what size front and rear. I purchased some new wheels for my Z06 in stock ZR1 19/20 combo and I'm looking for options other than the PS2 ZP and the Pilot Sport Cup. I know I could use Nitto Invo 285/30/19 and 345/25/20, but I'm looking for other choices. Thanks!

isnider

I think the super sport is still a few months out....supposed to be even better than the PS2, not a grippy as cup but better wet and longer tread life.

Ian

whatcop?

I haven't driven much on my PS2 but so far I am not a fan of the grip. Compared to the NT-05s I was running on my Z06. However, in the rain the PS2 is a great tire.

Lawdogg

Thanks for the replies! On the Tire Rack website, the Super Sports are available in 335 and 345/20 and 275/19, but the diameter difference front to rear is something like 1.4 inches compared to about .9 or so inches stock. I think that would be ok for the active handling and abs systems, but I'm not sure. Also the 335 and 345/20s are 28" in diameter which is a lot bigger than the oem diameter due to the larger aspect ratio. I also think that wouldn't be a problem, but I was hoping for some first hand experience.

Fizzex

ZR1 tires are 285/30-19 front and 335/25-20 rear. Currently, the closest available Michelin Super Sport rear tires to those are 345/30-20 which have a 0.9% difference in overall diameter compared to the OEM spec. tires. A 3% difference is the generally accepted maximum.

Comparable fronts have a 0.9% difference in overall diameter. However, they have a tread width that is 3.5% narrower than the OEM spec. tires.

OEM front tire, overall diameter = 25.73"

Michelin Super Sport front tire, overall diameter = 25.5" (-0.39" smaller than OEM).

OEM rear tire, overall diameter = 27.91"

Michelin Super Sport rear tire, overall diameter = 28.15" (0.24" larger than OEM)

Hence, there is a 2.18" difference in diameter between the OEM front and rear tire sizes and a 2.65" difference between the Michelin Super Sport front and rear tire diameters.

Current Michelin Super Sport tire sizes...

http://www.tirerack.com/tires/tires....ot+Super+Sport

michaelinmech

Could the 295/30-19 be used as the front tire together with the 345/30-20 rear in the SS ?

Or perhaps the 285/40-19 together with the 345/30-20 ?

Lawdogg

Oem diameters I've found are:
285/30/19: 25.8", rear 335/25/20: 26.6" for a difference of .8" http://www.tirerack.com/tires/tires....t+Sport+PS2+ZP

Super Sport diameter front 275/35/19: 26.6", rear 345/30/20 28.1 (335/30/19 28.0") for a difference of 1.5" (or 1.4"),

or Super Sport front 275/40/19: 27.7" for a difference of .4" (or .3").

Nothing is really close to the front rear diameter stock difference of .8" How close does it need to be without screwing up the abs and active handling systems?

michaelinmech

Lawdogg

I appreciate all the analysis. If one was to go with the Super Sport in 345/30-20 rear how would they pair with:

285/40-19 fronts or 295/30-19 fronts?

Fizzex

The OEM spec. ZR1 front tires have an O.D. of 25.8". Whereas the Michelin Super Sport 285/40-19 have an O.D. of 28" (8.7% greater) and thus too much of a disparity compared to the OEM tire.

However, the 295/30-19 Michelin Super Sport is within the allowable range having an O.D. of 26". A difference of only 0.9%. That said, the wider 295 tread width may result in mechanical interference, for example rubbing.

All tire sizes above can be verified on the Tire Rack website.

Lawdogg

I know there an allowable variance in the front to rear tire diameter difference, but not sure what it is. Fizzex, are you saying that the abs and active handling systems also require that the tire diameter be within a certain percentage of the oem diameter for that tire?

isnider

I think you can wait a couple months, the super sport will available in OEM sizes.

Ian

michaelinmech

All of the sizes the Super Sport will be/are available in are listed on the Tire Rack website. There are no other sizes coming.

Fizzex

Since the Michelin Super Sport front and rear tires are each within the allowable O.D. range when compared to the OEM front and rear tires then the F/R Michelin tires together will also be within the allowable range. Hence, no issues should occur with the TC or ABS systems, for example.

There are still potential issues, however. Since the Michelin front tire is wider (295 vs 285) it may result in interference/rubbing and possibly oversteer* or other unforeseen consequences. There's a reason GM used the 285 tire and cost alone was likely not the only factor.



*Most street cars are designed to have a slight understeer tendency and any improvement to front 'grip' can result in negating that understeer trait. Although this is seen by some as possibly making the car more neutral it can also have negative consequences in some situations.

isnider

Actually I just got back from Spring Mountain (they are exclusive Michelin and sponsered by them) and they said the super sports would be coming out in all Corvette OEM sizes by summer

Ian

Kyle Lemish

As far as different heights causing issues with the computer and active handling, it is not an issue at all, i was told when picking my drag radial set up with a rear tire that is shorter than the front, the car would invoke traction control constantly as the rear would be spinning faster than the front and the computer would think its spinning. That is NOT the case the car has no issues at all running that combo on 6 hour round trips to MIR and back.

michaelinmech

From your lips to Gawd's ear Ian. That will be great. It is exactly the opposite of what I was advised but I like your version so much better. How would we find out exactly what additional sizes and when? I need to purchase tires and, with your news, am hesitant to pull the trigger.

Cypher

Michael, are you not happy with the performance of the PS2 ZPs on your new Carbon?

isnider

From what we were told, it will all OEM corvette sizes in a few months. The release is in response to the Goodyear gen II tire that supposedly offered 30% better grip.

Sparkman

I happened to be in the classroom with Ian during the discussion regarding the Michelin Super Sport’s, and can vouch for the news Ian shared with you. I for one will be waiting a few months to see what materializes.

It was a pleasure meeting you last week, Ian. Great times BSing, and chasing you on the race track. Let me know if and when you decide to attend level 2, and I’ll try to schedule to do it again. Fine driving Buddy!

michaelinmech

The PS2 ZP's are Stellar !!!!!

I have a second set of wheels and am looking to do something different tire wise with those. More of an appearance nod than a performance enhancement, I am toying with squeezing some larger sizes on.

I am of the opinion that from a pure performance standpoint nothing can touch the PS2 or Cup tires for street use on our cars.