Yea its all about sidewall flex! Most tires say 44 max psi but I wouldn't suggest running more then 40 psi max and less then 35psi! Try one lap with 40 psi and then another with 35 psi, and see which your comfortable with and adjust from there! If you find yourself understeering add more air and less if you oversteering! It sound significant and I thought people were messin with me but you will notice 2 psi makes does make a difference!