A Study of Intake Air Pressure Sampling Position in a Throttle Body Module

In electric fuel injection (EFI) systems the intake air pressure is used as system load signal for calculating injection and ignition parameters together with engine speed. Part of an EFI system for motorcycles is a throttle body module with integrated pressure sensor. As motorcycle systems require smaller components than automotive applications the target for engineering is to minimize the component size and still fulfill other system requirements. Therefore the pressure sensor sampling point should be as close as possible to the throttle shaft to reduce the module size but with a sufficient distance to avoid signal distortion by unsteady flow. This paper describes how to find a suitable sampling position by combining static bench testing, dynamic vehicle testing and CFD analysis.