Background
ASX is Mitsubishi's contribution to the popular mini-SUV class. It has a new all-aluminum engine with variable camshafts, which is called MIVEC (Mitsubishi Innovative Valve timing Electronic Control system). The engine has unusually low compression ratio (14,9:1) but with the help of ceramic glow plugs, the cold starting capability is splendid. The low compression ratio results in lower peak cylinder pressure, which means that the engine can have high power output.
Stages of development
Vehicle measurements
The first step in the development of a new power system is to carry out measurements and driveability tests on the standard car. For these measurements, the car is fitted with a data logger, which collects engine-related data such as pressures and temperatures.
Development of electronics and hardware
The details that the system will be composed of, in the form of brackets, wiring and control unit, are developed and tested to ensure full functionality in the car.
Enigne test cell activities
The engine is removed from the car and installed in our engine laboratory. In the test cell measurements are performed on the standard engine, to get information about the engine characteristics.
With the baseline data in mind, we start the calibration of our system where we fine-tune all engine parameters throughout the rev range. In the testbed, we also adjust the transient characteristics to maximize engine response and driveability.
Vehicle test 2
When the system is ready in terms of basic calibration and hardware, the system is tested in the car. In addition to ensuring full functionality, there can also be some minor changes to driveability related parameters, to further improve the feeling of the car.
Long Term test
The result of the development is tested in a field trial in a number of vehicles, while the durability of the engine hardware is tested in the engine test cell. When all has passed the long term testing, the system is ready to be sold.