This Blow Off, or Dump valve, is for the BMW 135/235 N55 3.0 Turbo engines, that have the electronically controlled bypass valves. It is recommended for any vehicle where the boost pressure has been increased by an ECU software upgrade and for unmodified vehicles operating in warmer climates, as a solution to the many failures that have occurred. Unfortunately the failure doesn’t always result in a check engine light as the valve can still be blown open by the boost pressure, so you may not be aware that you are losing power due to this. This prevents the diaphragm from sealing.
Our alternative is a fully engineered solution offering both significantly improved reliability. Our valve is piston based, with no diaphragm to fail, and of all aluminium construction, it replaces the original unit with a pressure/vacuum operated piston valve that still also retains the desirable OEM ECU control, over valve actuation.