Fuel Economy Development for a CVT Powertrain on Roller-Chassis Dynamometer and Transfer to Dynamic Engine Testbed

The motorcycle and small engine industry is entering a chapter where emission legislation (EU5, BS6) is adapted to the automotive industries and especially CO2 emission is coming more and more into the focus of the OEMs, the legislative authorities and finally the end-user. Technologies like variable valve actuation, direct gasoline injection and turbo charging are state of the art in the automotive industry and have brought the efficiency of the internal combustion engine onto the next level. Nevertheless the small engine manufacturers are seeking for solutions which are cost efficient as well as simple and easy to apply. Even powertrain complexity is increasing the development efforts have to be kept moderate. Therefore, there is strong request for modern instrumentation and Testbeds which support an efficient and effective development process.

This paper describes the development on an 110cc scooter engine with the main focus on fuel consumption reduction during the hardware development on the engine Testbed as well as chassis dyno . Furthermore, it has been investigated how the efficiency, robustness and reproducibility of the development process and its test environments can be increased by using an advanced dynamic engine Testbed. This innovative Testbed is combined with a belt drive transmission which allows to operate as stationary single cylinder engine, as well as in power pack- (i.e. internal combustion engine including transmission) configuration under steady-state or dynamic operating mode.