A system and method for controlling an engine involves providing a pumping
torque estimation model. The model distinguishes between pumping losses
due to throttling and pumping losses due to valve flow losses. The model
is implemented by a pair of look-up tables. The data in each look-up
table reflect Pumping Mean Effective Pressure (PMEP), which is indicative
of the pumping work. The throttling loss table provides a first
contribution based on an engine delta pressure. The valve flow loss table
provides a second contribution based on an engine speed and a relative
airload. The first and second contributions are summed and then
multiplied by a predetermined factor to convert the pumping work (PMEP)
into pumping torque. The model will work with naturally-aspirated,
turbo-charged and super-charged air induction configurations and provides
improved altitude compensation. The model will also work with both
spark-ignition and compression-ignition configurations.