Development of Variable Cylinder Management System for Large Motorcycles
The world’s first variable cylinder management system, VCM system, for large motorcycles has been developed. The system uses an in-line four-cylinder, 1 137 cm3 engine as the base, and allows changing of the number of working cylinders from 2-cylinder to 3-cylinder to 4-cylinder. To eliminate an abrupt change of power delivery when shifting number of working cylinders, the electronically-controlled throttle valve (Throttle-By-Wire: TBW) is employed. Coupled with the harmonized control of the intake-and-exhaust valve deactivating system, the smooth switching of number of working cylinders suitable for motorcycles has been realized. As a result, while maintaining the same power output characteristics of the conventional engine, EURO 3 exhaust emission regulations are satisfied while attaining approximately 46% better fuel economy in the New European Driving Cycle mode (NEDC mode).