The new electronic valves offer a range of uses, including managing engine sound; recirculating a portion of a vehicle’s exhaust gases back into the cylinders to lower NOx emissions; as a bypass valve in energy recovery and tuning the exhaust system’s acoustics to support cylinder deactivation modes in light-load driving for fuel efficiency gains. The valves can help reduce CO2 emissions by providing vehicle manufacturers the ability to reduce muffler weight and volume while maintaining precise control over engine sound characteristics.
“Electronic exhaust valves are becoming increasingly important in current and future vehicle designs, whether they’re used to address vehicle emissions and pass-by noise requirements or to improve engine sound profiles and reduce muffler size,” said Ben Patel, vice president and chief technology officer, Tenneco. “Our unique modular approach enables vehicle manufacturers to comply with these regulations and meet the diverse needs of customers in an efficient and cost-competitive way.”
Tenneco’s new modular valve design offers greater flexibility for meeting application-specific requirements by supporting the use of various actuators with different signal interfaces and degrees of integrated electronics. In addition to distinct valve body concepts, including variants with inlays for highest acoustic requirements, and several body diameters, the design offers a variable actuator clocking, making them capable of meeting a diverse range of OEM applications.
The actuator is interchangeable using a simple mounting concept without any loose interface components. The new modular valve features a special, double-bearing design that minimizes external leakage and resists water projection and salt. The valves are suitable for exhaust gas temperatures of up to 750° C (peak) and ambient temperatures of up to 140° C (peak).
The valve delivers important acoustical benefits as well. For example, the electronically controlled flap can remain closed during normal driving conditions for a quieter ride and open during harder acceleration, creating lower backpressure, higher attenuation and more engine power for maximum efficiency. For such applications valve variants with and without fail-safe functions are available.