Dual-Stage Induction System (i-VTEC Engine)

Designed specifically for the Odyssey's i-VTEC engine, the induction system works in concert with the valvetrain to significantly boost torque across the engine's full operating range. Internal passages and two butterfly valves commanded by the powertrain control module are configured to provide two distinct modes of operation. The valves are closed at lower rpms. In this mode, the three cylinders on each bank draw air from only the nearer half of the manifold's internal chamber, or plenum. The volume of the plenum and the length of inlet passages are both tuned to maximize the resonance effect, wherein pressure waves are amplified within each half of the intake manifold at certain rpm ranges.
The amplified pressure waves significantly increase cylinder filling and the torque produced by the engine throughout the lower part of its rpm band.