Abstract: An induction system is designed for an engine that includes a manifold having a plenum in fluid communication with primary runners. A plenum valve is arranged between first and second chambers of the plenum that are respectively in fluid communication with first and second sets of the primary runners. The plenum valve is configured to move between open and closed positions to regulate flow between the first and second chambers. A secondary runner is arranged upstream from and in fluid communication with the plenum. The secondary runner includes first and second runner portions with the second runner portion being shorter than the first runner portion. A runner valve is arranged in the secondary runner between the first and second runner portions and is configured to selectively direct flow through the first and second runner portions to the plenum to obtain a desired effective tuning length.