Skunk2 Racing's Tuner Stage 4 Camshaft is designed as a performance upgrade to highly modified vehicles running the D15/ D16 VTEC engines. The Stage 4 camshaft will outperform all other Skunk2 Tuner offerings from idle to redline with no loss in drivability. A great match for max effort NA and Turbo engine builds. Tuner Stage 4's require a simple valve spring and retainer upgrade due to the additional lift, duration and increased RPM range. Our Tuner Stage 4's incorporate Skunk2 Racing's cutting-edge Fast Ramp and AMAX features, which are responsible for increasing overall performance, producing unmatched response from idle to redline. You can expect optimized mid-range and top-end horsepower/torque with peak power moved up the RPM band, producing a seamless VTEC crossover!