Abstract: A method for controlling spark timing. A plurality of tables provides borderline timing data contributors for each of a corresponding one of a plurality of different engine operating conditions. The contributors in each table are a function of engine speed and air charge. Background borderline spark timing is determined at a background computational rate from a summation of the borderline timing data in the plurality of tables data in the plurality of tables at engine speed measured at the borderline computational rate and air charge determined at the borderline computational rate. A one-dimensional table has borderline timing data contributors extracted from the provided tables. The extracted borderline timing data contributors are the engine sped measured at the borderline computational rate and the air charge determined at the borderline computational rate. From the one-dimensional table, foreground borderline spark timing is determined at a higher, foreground computational rate.

Abstract: A method for controlling spark timing. A plurality of tables provides borderline timing data contributors for each of a corresponding one of a plurality of different engine operating conditions. The contributors in each table are a function of engine speed and air charge. Background borderline spark timing is determined at a background computational rate from a summation of the borderline timing data in the plurality of tables data in the plurality of tables at engine speed measured at the borderline computational rate and air charge determined at the borderline computational rate. A one-dimensional table has borderline timing data contributors extracted from the provided tables. The extracted borderline timing data contributors are the engine speed measured at the borderline computational rate and the air charge determined at the borderline computational rate. From the one-dimensional table, foreground borderline spark timing is determined at a higher, foreground computational rate.

Abstract: An intake system for a multicylinder internal combustion engine includes a manifold having inlet runners for conducting charge air into the cylinders of an engine, and at least one secondary throttle valve situated within at least one of the inlet runners. An actuator positions the secondary throttle valve, with the actuator being operated by a controller. The controller receives a sensed value from at least one engine operating parameter sensor, determines an appropriate position for the secondary throttle valve and predicts an optimum transition point at which the secondary throttle valve transitions to the appropriate position. The controller then initiates operation of the actuator at a point before the transition point such that the engine smoothly transitions between a first operating condition and a second operating condition.