Live for Speed has very good physics, some of the best I have seen.. Its a racing sim for the PC that some guys created.
It doesn't have the tracks you need, but the physics are great. You can alter spring rates, tire pressures,alignments,ride heights, suspension...etc.
You can download the fully operational demo at liveforspeed.net (you get more tracks and cars if you pay for the full version..$20, I believe. )