Ricardo WAVE Simulation on the Effect of Exhaust Header Geometry to the Power and Torque of the UGM’s FSAE Engine

Abstract

Header is a component inside an exhaust system which delivers the exhaust gas flow produced by engine combustion process. UGM's FSAE car Bimasakti, which took part in a racing competition, needs components with excellent performance including the header component. The present study is aimed at obtaining the geometry of the header exhaust system that can optimize the power and torque of the engine KTM 450 SX-F while still complying with the Student Formula SAE competition's regulations. This research used an engine and one-dimensional gas dynamics simulation software known as the Ricardo WAVE. This software was used to simulate the powertrain system model of the 5th generation Bimasakti. From the initial model, changes towards the header geometry with variations in diameters and pipe lengths were conducted. After the best design has been obtained, developments towards at the above-mentioned design with additions of expansion chamber, stepped pipe, and diffuser shapes were then conducted. The obtained results showed that larger diameter of header can produce the better power and torque value at both low and high RPMs, whereas smaller diameter size would produce a better power and torque value at medium RPM. The effect of the use of longer header length can produce a better power and torque value at medium RPM, while shorter length would produce a better power and torque value at high RPM. Also, it is obtained that the addition of expansion chamber shape will reduce the engine's power and torque, while the addition of stepped pipe and diffuser shapes will increase the power and torque value at high RPM.