Blow off valve

Blow off valve A blowoff valve, (BOV, sometimes hooter valve, not to be confused with a ) does basically the same thing, but releases the air to the atmosphere. This creates a very distinctive sound desired by many who own turbocharged sports cars. Some blowoff valves are sold with shaped exits manufactured by brands such as TurboXS more specifically the RFL blow off valve that the hissing sound, as not all blowoff valves are the same, some make different noises and these designs are normally marketed towards the tuner crowd. For some owners this is the only reason to get a blowoff valve. Motor sports governed by the FIA have made it illegal to vent unmuffled blowoff valves to the atmosphere. In the United States, Australia and parts of Europe cars featuring unmuffled blowoff valves are illegal for street use