Camshaft - Exhaust - Stage 1 - Yamaha Stage 1 is designed for low end torque, Adds a 5%-10% power gain, Designed and dyno proven in the USA, Manufactured by utilizing state of the art valvetrain software, CNC machined from 8620 billet, case-hardened steel for an exact fit and lobe profile, Engineered to be drop-in cams, that use stock valve springs (unless otherwise noted)., Select cams feature Hot Cams Improved Throttle Design (ITR) technology; these cams improve throttle response throughout the entire rpm range while providing excellent power gains through the mid-range and top-end., For dual cam engine.