we have a FXO just 17 laps Race at KY2!

But the left front tire is so easy to be overheated! and It's air pressure reaches 250..

I have no idea how to make a right SET now!

Anyone use mouse can help me?

without having seen the setup, I suggest lowering the camber.
Perhaps giving it some more rear stabiliser.

Increase rear ARB and reduce the front rebound damping, thats a good start to reduce the understeer which is probably killing ur fronts considering ur using the mouse. Also reduce brake pressures and set it back by about 2% to prevent locking up.

Need a bit more info to help. Drive a few laps until the tyres get too hot then save the replay. When you watch the replay back put the camera in chase mode and watch in the force view (f).
You need to watch the force arrows between the front wheels and the road and see at which parts of the circuit they always go red, indicating that you have gone over the limit of grip.

Then its pretty much what Benji said above^^

If it's under braking: reduce the braking force and consider moving the brake balance towards the back a bit.

If its round the corner: Reduce understeer by changing the balance of roll stiffness between the front and rear. This can be done with the springs or ARBs. Also reduce the maximum steering lock both on the car setup and your own steering input.

If all the above are ok and its just the inner edge of the tyre getting too hot then its what Dan said: reduce the camber.

Use a lower lock level on the Limited Slip, it might mean your corner exit speed is a little lower, but then at the same time, pit every three laps or take a 2 second a lap hit on ext speeds? Otherwise I can't really say anything that hasn't been said.

Camber angle if the heat is just on one edge of the tyre, also a lot can be said about just turning the wheel enough to take the corner, and remember it's better to take the first part of the corner more gently and power out as straight as you can....