More than a decade ago, Skunk2’s engineers looked to the popular Integra Type R intake manifold for inspiration and went back to the drawing board. Skunk2’s Pro Series Intake Manifold for Honda's B-series VTEC engines (GS-R only) features a larger plenum and oversized runners when compared to the ITR manifold for maximum horsepower and torque gains. Instead of producing a manifold with a significantly oversized plenum and excessively short runners that would sacrifice mid-range power, the Pro Series manifold was designed for the “street enthusiast” who wants more power but doesn’t want to sacrifice mid-range performance to get it. The results are improved airflow, an enhanced venturi effect, and both mid-range and top-end power gains. Skunk2’s cast-aluminum Pro Series Intake Manifolds for Honda’s B-series engines are a direct-fit replacement for all B-series engines thanks to three separate flange designs and are compatible with all factory sensors and throttle bodies as large as 75mm. Pro Series Intake Manifolds offer horsepower and torque gains greater than competitors’ manifolds but without compromising mid-range power output. The design incorporates specially tapered runners as well as a larger, tapered plenum that together preserve mid-range power but increase and accelerate airflow to allow for significant top-end power gains. Pro Series Intake Manifold runner exits are also machined to best match the cylinder head’s ports. Skunk2’s Pro Series Intake Manifold’s shape and design also increases wave scavenging effects at the engine’s ideal operating range, which allow for a broad increase in usable power.