How does a blow off valve work?

Blow off valve: “A blow-off valve, dump valve or compressor bypass valve, is a pressure release system present in most turbocharged engines. Its main purpose is to take the strain off the turbo when the throttle is suddenly released.” In other words, a blow-off valve is something that releases the pressure of a turbo when it's not used.

How does it work?

“A blowoff valve is connected by a vacuum hose to the intake manifold after the throttle plate. When the throttle is closed, the relative manifold pressure drops below atmospheric pressure and the resulting pressure differential operates the blow-off valve piston. The excess pressure from the turbocharger is then vented into the atmosphere or recirculated into the intake upstream of the compressor inlet.” In other words, it opens the valve and releases the pressure not used in vehicles which preserves the turbo.

What's the primary reason we have a blow-off.

The number one reason we have a blow-off valve is to realise the pressure that is not used and can cause harm to the turbo in some cases engine, but the second reason we have it is because it sounds cool. Here at BCR Automotive, our turboed cars come with a blow-off valve, but if you wanted an aftermarket one we would be more than happy to show you where to get one.