X25

I do have the MPSC ZP tires that come with Z07 and ZR1/PDE, and started wondering since its build and nature is much different than any street tire: is the GM's recommended street pressure still 30 PSI (cold) for these tires?

What about track? Is it still 26 PSI? Michelin itself recommends 25 PSI front / 28 PSI rear (cold) to use Cup tires at the track, but it does not mention any differences for ZP and non-ZP cup tires, so I'm not even sure if that recommendation applies to these tires as well. I should mention, though, TireRack lists Michelin pdf doc that gives these recommendations under the Cup ZP tires' section as well.

anarchy67

the recommended pressure is embossed on the wall of the tire.

Boomer111

I believe the wall of the tire shows the max psi for the load limit of the tire.

AT LEAST THAT IS HOW IT IS ON ANY OTHER TIRE I HAVE SEEN.

RUN THEM SO THEY SHOW 30-32 HOT PSI.

30 hot is supposed to be the best temp for wear and performance.

Do a search for Evil Twin and tire tuning.

X25

That's actually the max cold pressure the tire is designed for, so you might run into issues if that's what you use

X25

When I run the PS2 at 30 cold, they settle at around 33-34PSI. I've heard from many that this is ideal. However, Cup ZP tires will go higher pressures if I start from 30 cold, which is why I am wondering if even GM recommends another pressure for these tires.

Do any of you have a Z07 or a ZR1 w/PDE (and cup tires)? What does your car's label by the door sill recommend in terms of tire pressures?

BSPC608

2013 ZR1 with PDE and cup tires installed at factory door says 30 PSI cold.

Boomer111

The door sticker is a idiot sticker so people do not inflate their tires to the PSI marking on the tire.

30 cold is a good starting point and if you want to take it a step further look into "tire tuning".

I run 28 cold and it gives me 31 hot in 80-90 degree weather.

anarchy67

unless you run nitrogen.

X25

I don't think running nitrogen would change targets that drastically. After all, nitrogen expands, too?

Boomer111

At about half the psi increase as air.

sg7025

I ran mine last weekend at Thunderhill Raceway aiming for 36 Hot and it seemed to work out pretty well. I found recomendations on the website below from Michelin.

http://www.tirerack.com/tires/tirete...nd_Feeding.pdf

-Greg

Robert R1

I'm ordering a set of Sport Cups for my next trackday also.

I'm going to go with the Michelin recommendation and also get my alignment done with at least -2.0 of negative camber all around, 0 toe in front and negative toe in the rear.

sg7025

Let us know what the best price you find on those are. I might have to sell something or someone to buy my next set, but it'll be worth it!

Robert R1

Will do. So far Tirerack seems to the cheapest which isn't saying much...

Robert R1

Update. Ended up ordering a set through tire buyer.com

They have a 70 dollar rebate also "retialmenot12" coupon code will give you another 12% off. That's the best I could find.