One of the rules of Student Formula SAE is air intake must have a restrictor located after the throttle body with 20 mm maximum diameter. It causes engine power and torque decreased. To increase engine performance, modify the bellmouth radius and venturi restrictor length are some of options. The authors analyzed the effect of them on power and torque produced by KTM 450 SXF engine of Bimasakti UGM’s 9th generation car (BM-9). The authors made 9 design variations then simulated by Ricardo Wave 2016.1 and Ansys Fluent 18.1 software. The result is, greater the bellmouth radius and venturi restrictor length produced higher value of peak power and peak torque.
Keywords: Bellmouth; Restrictor; Air Intake; Engine Performance; Ricardo Wave; Ansys Fluent.