Mapping Procedure Applied to General Engine Management System for Spark Plug Engines

This work presents an experimental procedure to find the best operating point for a spark ignition engine controlled by a general Engine Management System. The ECU control allows changing the ignition and fuel injection timing as a function of load and rotational speed, beyond configuring the whole system according to the sensors and actuators types. The ignition dwell time and the best moment to start the injection fuel can be controlled accurately by this system. In addition, this electronic system allows adjustments in real time with engine installed onto a dynamometric test stand. This work describes the experimental apparatus, sensors characteristics used and also the methodology to accomplish the adjustments in the ECU maps, seeking to obtain the best performance. Comparison performance data for the standard engine and the proposed configuration are presented here, showing a 50% gain for a spark ignition engine of 1300 cm³, four cylinders in line, and 16 valves. The standard configuration is an aspirated engine with an original ECU developed aiming a balance a number of sometimes opposing objectives - vehicle emissions, engine power output, fuel consumption and engine lifetime in order to best meet requirements. A new configuration consists of adding the GT12 turbocompressor with the intercooler system, oil cooler and the MoTec M4 ECU also responsible for controlling the boost pressure of the turbo compressor electronically (boost drive). This engine with the new configuration will be used in airplanes, so the exhaust emission is not an important parameter at this job. Due to this reason, all the maps for the MoTec M4 ECU have been elaborated without use any data from the original ECU.