Stiffer engine mounts will help the car's performance by limiting how much the enigne moves, and therefore less energy will be spent on moving the engine and more will be there for moving the car along.
Only the front engine mount is available in a stiffer design (this is the one that's shaped like a mushroom). This mount is the same as the front engine mount on A1 Volkswagens, and mine came from Techtonics. The rear two engine mounts are Fox-specific. Audi 80 parts will work, but they are not any stiffer than Fox mounts.What did it do?
I'm not sure. In all honesty, replacing only one engine mount will not help much. I decided to try it anyway, because when my car was on a dyno in the past, the engine not only moved side-to-side (along the axis of the crankshaft), but also front to back as the car accelerated and decelerated.Pictures