CONTINUOUSLY VARYING EXHAUST PIPE LENGTH AND DIAMETER TO IMPROVE THE PERFORMANCE OF A NATURALLY ASPIRATED SI ENGINE

Wave tuning is a concept which increases the volumetric efficiency of a naturally aspirated engine by providing a scavenging effect to clear out residual gases and increase inflow of fresh charge. This paper analyses the effects of tuning pulsating sonic wave produced over a broad range of speeds in the exhaust manifold of a single cylinder 510 cc SI engine, on the power and torque of the engine. 1-D model of the engine is modeled using Ricardo Wave. The simulation results obtained through the parametric analysis are compared with the standard data provided by the engine testing. On average, 7% increase in torque and 6% increase in power are observed by continuously varying exhaust pipe length. While continuously varying exhaust pipe diameter, 6% increase in torque and power is observed. When combined together, the continuously varying exhaust pipe length and diameter produce 8.5% increased torque and 9% increased power, respectively.