Up to 4 Races on YHC tires?

[Keith Smith]

I ran the Norcal IKF, replacing tires each race. I have been trying to run the tires at club races or practice and can only get 2 or 3 total days out of them. What are you guys doing to make them live long and still be fast? It is very hot here in Norcal, track temps over 150 degrees. My Invader looses grip quickly with worn tires, do you alter the pressures as they wear (compared to new) or change chassis set up?????