The OEM MazdaSpeed Bypass Valve/BPV  is well suited for up to 18-20psi of boost. Past this point it starts to leak air and torque drops off even if boost is maintained above 20psi. All big turbo cars should upgrade their BPVs. On some cars even the stock K04 turbo is hindered by a leaking OEM valve. The Synapse Valve is the fastest BPV on the market and you can run it as a BOV as well using our Guardian Angel. For this reason we started to carry it right here in our store.

This Synapse valve won’t leak even up to 60psi of boost and the fast response means excellent driveability as well as fast spool and excellent re-spool between shifts. Our BPV of choice for the MazdaSpeed.

If you want more information on why an upgraded BPV is important read our tech article here.