This compound has been a favorite of race driving schools because of its modulation characteristics. Used exclusively at race schools such as Bob Bondurant, Derek Daly, and Jim Russell because of is forgiving nature. 90 Compounds is very easy on the discs, yet has higher cold bite than 83compound along with less torque rise for improved modulation. 90 Compound has been replaced by 97 in most applications, but is still available in a limited number of applications. 90 compound can be replaced with 11 compound. 90 Recommended Applications Recommended for applications that demand good wear and modulation. GT, SCCA Racing and Porsche/BMW Club Racing.