Blowoff valves are pressure release systems in turbocharged engines. They prevent compressor surge and reduce wear on both the turbocharger and engine. Blowoff valves relieve the damaging effects of compressor "surge loading" by allowing the compressed air to vent to the atmosphere - not only does this take stress of your car's powerplant, but it also makes a distinct hissing sound.

The Active Autowerke Blowoff Valve is a pull-type BOV best suited for high-horsepower applications. Constructed from an all aluminum cast body, with a large single stage, steel pull-type valve to handle the extreme pressure and airflow discharge volume that is associated with high boost / horsepower applications. The BOV is engineered for up to 43psi of boost and will function precisely on BMWs producing more than the 500 horsepower range.

Not for sale or use in the state of California on any pollution-controlled vehicle as per the California Air Resources Board.