I am a retired experienced car enthusiast, and one of my retirement hobbies is to autocross my car. I mainly run in local regional events sanctioned by the SCCA and occasionally attend a National Level event.
I currently campaign my 2012 Miata in the STR class of the SCCA. Ran in the C Street class for 4 years, added more mods. to the car in 2020 and have been running in the STR class in 2020 and 2021. I changed to coilovers, ECU tune, replaced all suspension bushings with polyurethane and changed to 245/40/R17 tires. I did not change the diff. mount bushings or the motor mounts........probably a mistake!
I ran at the Toledo, Ohio ProSolo event on 7/23/21. I broke the diff. mount on my 4th start and car is now in the replace broken parts mode, waiting on factory OEM diff. mount to arrive.
I am planning on changing the motor mounts and wanted a recommendation on what stiffness of AWR mount I should use, 70 or 88 durometer; or should I use the competition rubber motor mounts you sell? Car is used for autocross only, rarely street driven, and never tracked.
I have polyurethane diff. mount bushings that I plan on installing in the new OEM diff. mount.
Thanks for your help and guidance!