[thstone]

Tires should start at factory pressure, 29F/36R. If you're driving hard, then the pressures will go up and the tires will start to slide around rather than grip like they usually do so you might need to bleed off a little air as you go harder. My PS2's feel like they are riding on grease when the pressures get too high and I am pushing the car hard.

Make sure the alignment is spot on.

Have all of the suspension re-checked and tell the tech what happened. A health check is a nothing compared to a performance handling check. Anything worn will expose itself at 115mph in a corner.

Shifting in a corner at 115mph will definitely upset the balance. Get your shifting done before the corner.