correct tire pressure

[GReeK]

I was at the track yesterday and on certain turns my back kept coming loose. I know it has to do with suspension set up and road surface but I just wanted to know what it the correct tire pressure.

facts:
Michelin pilot power 2ct
weather 100F
checked pressure right after I got off the track after first incident: 42psi (hot Tire). I reduced it to 35 while still hot
second time around I reduced the psi: 33psi (hot tire)
third time I reduced to 31 psi ( hot tire)

tire was still coming a bit loose on same turns

what is the correct pressure cold and hot?

[heffergm]

As a rough guide, use the 10/20% rule. Take a cold tire pressure reading. Go out, run some hot laps, come back in and check your pressures again. You want a 10% increase in the front and a 20% increase in the rear.

As a better bet, if there's a tire vendor there, as them what pressures they're recommending.

[GReeK]

I started with cold 36psi rear and 33psi front. thats what I use on the street. when I got back after the first session I had 44 rear and 40 front. the tire says 42 max psi cold front and back. So I started taking air out every session until it felt right. The tire vendors said 30 rear 28 front, but I think that was too low

[crabman]

Michelin tires like 28 - 30 cold. The vendors are right on target, I've run these pressures and the tires work great. On the street I run 32 front 36 rear.

[Monstaman]

Originally Posted by GReeK

The tire vendors said 30 rear 28 front,

Perfect, that is what I run all the time, traction is king.

36 front and 42 rear are MAX LOADED pressures, ie panniers, two people and belly full of McDees.

Given the weight of the Tard then 28/30 is the perfect set-up.

[PedroHM]

There is always a tire guy at the track just ask him.

road tyres always gets the same answer at the track - 30psi front and back cold.

BUT as the day warms up you may want to check the hot pressure after each session and add 1-2psi to stop it getting too hot and melting.

[Caidly]

Originally Posted by crabman

Michelin tires like 28 - 30 cold. The vendors are right on target, I've run these pressures and the tires work great. On the street I run 32 front 36 rear.

Rear tire will heat up more than the front and therefore increase pressure more, why do you put more to start in the rear?

I run 28.5/31 rear/front on street and track. I ride hard (when not using as transport to/from work) and have 3k on my Corsas with the looks of at least another 1-2k more.

[Monstaman]

Originally Posted by CTarna

and have 3k on my Corsas with the looks of at least another 1-2k more.

I got 6008 km (3755miles) out of my sync and was stoked about that!!

No point in running them hard IMO .. mind you too jelly and it is worserererer

[851]

I was also at the track with my rear getting loose ... turns out the center was worn to the bands Joking aside, I had to change the tire at the track and the specialist there advised for the Corsa IIIs to be set with the front at 31 psi and the rear at 29 psi, using hot pressures. His opinion is that cold pressures are not very reliable, taking the pressure after coming in from a session is best. But he also said street tires are less sensitive to pressure and racing rubber.

[GReeK]

so, coming off a session while the tires are still hot, what psi I should be looking for?