BOV boost pressure relief valve AMAZING SOUND EFFECT !!! It protects your turbo !!! Valve with total air release to the atmosphere, equipped with a Dual-Drive system based on 2 pistons. Provides fast response time and maintains a high boost. The perfect sound of the valve is ensured by the design based on the venturi. The series DV valve forces the air into the circulation, while the blow-off valve - the atmospheric valve lets the air out, which protects your turbo and at the same time spends amazing sound effect-distinctive PSSSSSTT !!!! High quality workmanship. Mounting bolt spacing: 46 mm. Boost pressure relief valve BOV AMAZING SOUND EFFECT! Protects your turbo !!! Valve with total air release to the atmosphere. Equipped with a Dual-Drive system based on 2 pistons. Provides fast response time and maintains a high boost. The perfect sound of the valve is ensured by the design based on the venturi. The series DV valve forces the air into the circulation, while the Blow Off valve - the atmospheric valve lets the air out, which protects your turbo and at the same time delivers amazing sound effect - characteristic of PSSSSSTT !!!! High quality workmanship.