With reducing declination of rear differential mount bush, it will improve response of up shifting and acceleration performance.

CUSCO added product on its line up for latest model of Subaru Impreza WRX / STI. As motorsports expert, during products developing for GRB Impreza, CUSCO has found that the rear member collar and differential mount collars would give you massive effect and decided to add them on production line up.

With this part, you can feel response more directly compare to reinforcement bushings.

Installation is simple. You will NOT need to take off original bushings and swap. Just add these collars.