Skunk2 is proud to introduce the highly anticipated Centerfeed Plenum for the Honda B and K Ultra Race Intake Manifolds The Ultra Race Centerfeed Plenum has been designed to further improve airflow and reduce lean conditions associated with side - fed manifolds, by moving the throttle body forward and centering it above all intake ports. The center feed plenum works best with high RPM naturally aspirated engines and all turbochargedsupercharged applications.