Skunk2 Racing's Pro-Series Intake Manifold improves airflow thus increasing horsepower by as much as 8 percent over stock manifolds on stock engines and even more on modified or forced-induction engines. Skunk2 manifolds significantly increase horsepower between 3000-8800 rpm; the broadest powerband increase in the industry. Skunk2's new Pro-Series design features a 22 percent increase in power over the previous design. Engineered with a larger plenum and tapered runners, Skunk2 manifolds increase and accelerate airflow, and are designed to increase the effects of wave scavenging at the engine's optimum operating RPM range providing a broad overall increase in usable power. Each runner entry is also modified to balance airflow between cylinders. Oversized throttle bodies can be used as a result of the modified IAC opening on the flange. Like OEM factory manifolds, Skunk2 manifolds are shell molded and CNC machined, to achieve superior strength, high-quality finish, and a precise fit. Each manifold is vacuum tested to ensure quality and leakfree operation. The Skunk2 Pro-Series manifold utilizes all stock sensors and auxiliaries for a simple bolt-on installation that delivers maximum power. Made from high-grade 356 aluminum and features OEM quality shell molded casting.