Goodyear GS-CS slicks?

also, i got these slightly used Goodyear GS-CS racing tires. 255 50 16 for autox.
anybody ever use these? i don't know how good they are since they are my first racing tire. i ran them 38 lbs front, 34 lbs rear and i could still feel the sidewall flexing. more pressure?

I don't Auto-X, but attend open track sessions and the last one I ran the GS-CS tires. Usually I run Hoosiers, but was given a set to try.

I run 36 front and 34 rear (cold) for road racing.

Chalk mark your sidewall up onto the tread and see what it looks like after a session. That will tell you if you're using all, most or some of your tire.

thanks. went to autox last week and ran 42 psi all around. the fronts rose to 45 and i let out a little in the back to 40.

also used some chalk. no rollover. those pressures are really high, but with the lower speed sharp turns at autox, i noticed much less sidewall flex than when they were at 34-35.

then i rode in my friend's 99 SS with 275 Hoosiers all around for a fun run. he definitely has more grip. i need to go to 275s when these are done.