This incredible kit for the 9R Patriot engine provides significant horsepower gains with instant throttle response. The kit combines a lightweight silencer which reduces weight by 7.7 pounds and delivers an additional 2 horsepower with Power Dome™ Billet heads. The heads provide an additional 3 horsepower peak and 4-8 in the midrange for significant performance gains from top to bottom. Getting this additional horsepower to the ground is a Power Shift™ Clutch Kit feature Magnum Force™ Weights for optimum performance and easy adjustability. No fuel changes required and 91 octane compatible.