So here is my idea for a hybrid motormount setup, since the car is going to be a street car, i want some comfort. I was thinking about using a new OEM mount on the passenger side and on the easily rippable driver's side, an aluminum one. Any thoughts??

 

even with the other being stock, you're still going to get huge vibrations.

i'd go with the noltec mounts or the home made "polyurethane sandwich" mounts.

 

i was thinking of sandwiching rubber ends on a milled down alum mounts, think it will work?

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/motor-mounts-521858/

aluminum and comfortable street don't mix.

there is also a link in that thread:

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/motor-mount-163324/

 

I worked as an engineer designing hydraulic engine mounts and suspension links/bushings for 5 years and did a lot of vehicle/ride testing as a result. I can tell you definitively that you do not want to unbalance the system by using a hard mount to one side a soft mount to the other---the worst part being that you will tear up your mounting joint and or cradle.

The advantage to using hard mounts: no powertrain hop over rough road or roll during engine torquing--solid feel. The disadvantage: noise and idle shake.

The FD uses hydraulic mounts allowing the use of soft rubber to control idle shake and the hydraulic portion to control engine hop----the design is not however suited to control engine torquing which explains the often ripped stock mounts.

If you want the best comfort---stick with the stock mounts. If you can handle the extra noise and vibration, go with something stiffer like the poly mounts. I went with the Mazdaspeed mounts which seemed like a good tradeoff. My friend has poly mounts for the engine and diff though and I can honestly say that they aren't that much worse, but it is noticeable....