Easily one of the best bang for the buck 10th Gen Civic Si mods out there, if not, THE best. The rear motor mount prevents the engine from swaying back and forth. In a turbo car, the torque hits hard enough to cause the stock mount to max out the soft, partial bushing area. This causes a bang or a hard knocking sound in between shifts and ends up eating up some of your power and torque through parasitic loss. When you put in the Perrin motor mount insert, the bushing holds up much better to the engine wanting to flex. Ultimately, this allows the car to plant the tires to the road better, makes the transmission move less causing smoother shifts, and prevents the mount from banging around too much. For the price, you wouldn't think this is a very effective mod, but it is. The best part about it is it's very easy to install and the increase in vibration is barely noticable, especially compared to other mounts on the market.
