BOV Filter 38mmBOV Filter 38mm The BOV Filter 38mm is a genuine Turbosmart blow off valve engineered to improve boost response, throttle lift control and reliability in high performance turbo applications. Why Buy from Torque Lab? Torque Lab supplies genuine performance parts for serious street and track builds across Europe. We focus on technically correct fitment, strong SEO friendly product support and proven brands trusted in the tuning scene.