2012 NC Miata - Broken Diff. Mount & Rec. Motor Mount

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Oldmac
Posts: 4
Joined: Thu Feb 28, 2013 6:39 am

2012 NC Miata - Broken Diff. Mount & Rec. Motor Mount

Post by Oldmac »

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! :) ........... Oldmac
Greg @ GWR
Posts: 63
Joined: Mon Nov 12, 2018 3:20 pm

Re: 2012 NC Miata - Broken Diff. Mount & Rec. Motor Mount

Post by Greg @ GWR »

Typically we recommend the rubber competition mounts to autocross guys because their cars still see a lot of street time and the poly mounts cause a lot of NVH. Since your car is Autocross focused and not a street car then the 70d mounts should be fine. Poly mounts take some time to break-in, so at first they will feel harsher than they will later. The 88d mounts would be aimed at a hardcore full race car, something with a lot of added HP.
The Only Speed is Mazdaspeed
Oldmac
Posts: 4
Joined: Thu Feb 28, 2013 6:39 am

Re: 2012 NC Miata - Broken Diff. Mount & Rec. Motor Mount

Post by Oldmac »

Thanks for the reply and recommendation. :)

I will be ordering the polyurethane motor mounts shortly! ............ Oldmac
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