Manufactured exclusively from super-clean, chrome-silicone wire milled in Japan, Skunk2 Alpha Valve Springs for Honda D15/ D16 VTEC engines are a product of the company years of racing and engine building experiences. Alpha Valve Springs are able to prevent valve float and maintain valvetrain stability at engine speeds in excess of 10,000 rpm. Skunk2 designs, develops, and tests its entire valvetrain lineup in-house to ensure superior quality and maximum performance gains. During development, each valvetrain component is tested both on the dyno and the road, including 11,000 rpm drag racing engines and 17,000 rpm superbikes. Manufactured from the best materials available, Skunk2 valvetrain components provide exceptional performance, reliability, and quality and remain standard-issue on each Skunk2 vehicle that we build and support.