Abstract: A method and control apparatus for an internal combustion engine that allows an operator to calibrate engine performance relative to an engine operating characteristic. The control apparatus comprises a base engine control map that correlates values of the characteristic with values of a base engine control, a trim control map that correlates the values of the characteristic with values of a trim control, an engine control unit that obtains from the base engine control and trim control maps the respective base engine control and trim control values that are based on the characteristic value, and a panel that is operatively coupled with the engine control unit and includes a first switch regulating a trim signal supplied to the engine control unit. The trim control map is separated from the base control map. The engine control unit calculates an engine operating control value based on the obtained values.

Abstract: An engine management system for an internal combustion engine. The engine management system comprises an engine control system calculating an engine operating control value, a palm-size computer transportable relative to the engine control system, and an external computer communicating with the palm-size computer. The engine operating control value is adapted to be supplied to the internal combustion engine to vary engine performance. The palm-size computer has height, width, and thickness dimensions that are no larger than approximately 6 inches by approximately 4 inches by approximately 1 inch. The palm-size computer runs a set of engine management tools that communicate engine management data to the engine control system. The external computer downloads to the palm-size computer engine management tools and engine management files, and uploads from the palm-size computer engine management files.