A Model for Predicting Engine Torque Response during Rapid Throttle Transients in Port-injected Spark-ignition Engines

Equations describing the transient behaviour of air and liquid fuel in the intake system of port injected engines are used to predict firstly the variations in air/fuel ratio and ultimately the variations in engine torque that result from rapid throttle openings. Corresponding values of measured and predicted data are compared over a range of conditions and show that the model predicts essentially the correct trends.