When it comes to car modification, the popularity of blow-off valves is unparalleled. This is due to the crucial role they play in turbocharged engines, where they prevent the turbo from stalling by redirecting excess air pressure. However, there are other names for blow-off valves including diverter valves, compressor bypass valves, turbo relief valves, and atmospheric valves. Diverter valves work by redirecting the excess air back into the intake system, while compressor bypass valves direct the air to the intake between the turbocharger and the throttle body. Turbo relief valves can also prevent compressor surge, while atmospheric valves vent the excess air into the atmosphere, creating the signature "pshh" sound. Whatever you choose to call it, a blow-off valve is an essential tool for any turbocharged car owner.