Engine Exhaust Tonal Frequency PDF

A technical documentation that outlines the calculation of engine exhaust tones based on cylinder firing rates and engine firing rates. It presents the formulae used to determine the cylinder firing rate (CFR) for both 2-cycle and 4-cycle engines and the engine firing rate (EFR) depending on the number of cylinders. The example of a 4-cylinder inline 4-stroke engine is provided along with a spreadsheet that tabulates RPM against various harmonic frequencies such as CFR, 2xCFR, 4xCFR, EFR, 2xEFR, and 4xEFR.