Reduce drivetrain shudder under hard acceleration by installing a PERRIN Pitch Stop mount. The factory pitch stop mount is designed to control the pitching of the engine and transmission under light to normal acceleration. Subaru's with power and drivetrain upgrades will need PERRIN's more aggressive option. *What does a pitch stop mount do?* 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 factory pitch stop is made of plastic with soft rubber bushings, allowing for a significant amount of movement under hard driving conditions, creating drivetrain slop & shudder. *Why do I need the PERRIN Pitch Stop Mount?* The PERRIN Pitch Stop mount controls the movement of the drivetrain in both on and off throttle driving giving the driver a more positive feel and literally putting more power to the wheels by eliminating lost energy. *Construction* The PERRIN Pitch Stop Mounts body is machined from 6061 billet aluminum .and features stiff polyurethane bushings (not soft rubber). The bushings are as stiff as possible without introducing excessive NVH. (noise vibration harshness).