Under hard acceleration, the drivetrain is being twisted front to back from front axle torque twist. To control this front to back twisting, Subaru created a pitch stop mount. 

The Kartboy Aluminum Engine pitch stop mount is a solid one piece CNC cut mount that prevents pitching movement of the motor and transmission during hard acceleration and deceleration. This translates to less wasted energy and more power to the wheels. This mount shares the same high quality as you have come to expect from all Kartboy products, and will not disappoint .