Acoustic Valve

The search for improved fuel-efficiency has inspired new technologies, such as cylinder deactivation. In turn, these new technologies have led to an increased need for active valves in exhaust systems that can perform functions like adaptive acoustic attenuation and sound shaping. 
To meet this need, BOSAL has developed a modular platform of active acoustic valves that offer superior performance while remaining cost-effective.

Acoustic valves are integrated in the cold end emission control system to improve the trade-off between low frequent noise and backpressure, enabling either more compact silencers or better noise comfort. However, all acoustic valves present specific design and tuning challenges with regard to the generation of undesirable noise, durability and cost. It is therefore important to apply a modular design that covers specific cases, for example for engines with cylinder deactivation. BOSAL possesses the expertise required to be able to provide the right valve for the right application.

The valves are electronically actuated and open in response to engine load and speed, vehicle speed and driving style.  Valve variants with a continuously variable and controllable valve angle allow precise and controlled trade-off.


  • Modular patented design allowing various applications and customisation
  • Compact and low weight
  • Wide range of diameters
  • Strict tolerances resulting in low parasitic noise
  • Cost-effective
  • Durable smart bearing solution
BOSAL acoustic solutions - acoustic valve