Pacembellum

So it’s looking like it may drizzle on Sunday at Thunderhill. I just mounted up a fresh set of ZP Sport cup 2 on my spare wheels. Do you think I’ll be fine if I just go slower than normal and run in PTM wet mode? What should my “hot” pressure be in the wet I’ve heard to raise it up 3 or 4 psi? I start normally at 26-27 and end up around 33-34 should I start at 30?

i could run my street wheels with ZP super sports instead but I just put brand new fronts on and if the track is dry I’ll end up hammering the edges so leaning to the sport cup 2’s.

any thoughts?

shizon'00

If the track is wet, I'd run the super sports. You won't eat them up much while it's wet. If the track is damp, you'll be fine on the cup2. Do you have the ability to bring both and change at the track as conditions change?

Yes, starting at 30 cold should be a good start and adjust from there.

Pacembellum

Yeah I can just have my buddy bring my sport cup 2 just in case I’ll leave the MPSS on if it's very wet and raining, I don’t have a trailer yet. It is only expected to rain a tenth of an inch all day it’s not going to be a ton of rain.

shizon'00

I'd probably just run the cup2 tires then if it's not much rain. If you can bring both, it's nice to have options. Take it down a notch and use the lessened grip to focus on car control at lower speeds until a dry line forms.

Have fun. I'm jealous your session is starting already. I still have a month. Ugh

Bill Dearborn

Depends on how wet the track is. For track duty GM recommends a cold pressure setting of 26 psi with the Cup2s. If it is just damp I would raise the cold pressure 2 or 3 psi or maybe just leave it at the 30 psi street setting. All tread does is provide an empty space for water to squeeze into from the blocks of rubber touching the ground, it really helps when there is a lot of water on the track. However, when the track is just damp it doesn't help that much. Raising the pressure on your Cup2s will reduce the area of tire in contact with the ground and help break through the water film on the pavement. The idea is to not push them in the corners to much during the first few laps but get in some triple digit speeds on the straights so the tires can build some heat in them. As they warm up you can get better cornering grip.

The first time I took my Z06 to the track it was raining and I had a choice of running a set of Hoosiers or my 2000 mile Cup2s. I ran the Cup2s using the Wet Mode. After a few laps to see how the car actually worked on track I was able to get around quite well in the rain with the Cup2s. The whole thing is you need to be smoooooooth.

Bill

Pacembellum

thank you Bill. Very thorough. I also have a track alignment which will help keep the tires on that inner tread with the rain grooves.