ProCharger AV006A-003 - Bullet Bypass/Anti-Surge Valve - Closed

Bypass Valves vs Blow Off Valves
Blowers are always producing some amount of boost as they are belt driven, where a turbo spools up as the exhaust velocity is increased. Bypass valves are used with blowers since they always relieve the boost until near zero vacuum (heavy throttle) is achieved. Blow-off valves are designed to relieve boost at a set amount of boost, and can cause boost stacking when used with a blower. Light springs can be used with blow-off valves so that they can be used with blowers, and many have reported success with doing so. Unless a blow off valve is properly set up with a light spring though, the boost that is built up places a load on the blower that is hard on it, plus it will try to slow the blower down which can cause belt slippage. Stacked up boost will also try to find weak spot in the tubing and hoses to blow out of. This is why Bypass Valves are better than Blow Off Valves.