Mazdaspeed 3/6 Recirculating Bypass Valve

The MS3-RBV was designed for those who want a replacement recirculating bypass valve that can handle any boost you throw at it.  Unlike full vent-to-atmosphere or hybrid recirculating/vent-to-atmospohere valves, the MS3-RBV vents excess pressure back to the intake, preventing any transient rich AFR conditions that can lead to backfiring.