The Plymouth Prowler, active noise control exhaust system. Part I: Noise reduction

Abstract

An active noise control exhaust system or electronic exhaust system was developed for the Plymouth Prowler to demonstrate the ability to reduce backpressure greatly while also significantly reducing the exhaust noise. An electronic exhaust system is typically composed of passive and active elements. One of the major advantages of electronic exhaust systems is that most of the flow restrictions in the passive elements can be removed; this is reponsible for the backpressure reduction. Reduced backpressure typically results in a 3% to 6% horsepower gain at the rated engine speed of the vehicle and increases torque over most of the engine speed range. The electronic exhaust system also has the capability of greatly reducing the exhaust noise. The active elements can produce antinoise at very high levels such that, when combined with the unwanted exhaust noise, an overall decrease in the radiated tailpipe noise occurs. This allows the vehicle to meet the legal passby requirements with significant margin while maintaining appropraite sound quality characteristics. This paper will describe the system developed for the Prowler and the resulting performance gains.