Tire pressure for best cornering performance?

Ya, Come to think of it I remember watching some tuning show talking about how manufacturers design cars to understeer (Acura RSX was the test car). So the tuners had to put a whole new suspension and race wheels and engine mods, etc to get it race ready. They put it to understeer because its safer than oversteering I guess, at least a novice can keep an understeering car under controll.