A Comparison of Fuel Mangement Schemes A Comparison of Fuel management Schemes. Volume changes due to volumetric efficiency of engine, easily corrected with mapping. Very difficult to calculate pressure when calibrating turbocharged engines Pressure is rarely measured, a barometric pressure switch is used and is merely a gross calculation. Any change in engine, either mechanical or calibration, alter all other parameters making it very difficult to tune accurately Key Benefits Lowest restriction due to lack of air flow measuring device.
Manifold design is open without limits of porting to single air flow measuring device.
Calibration for turbo engines enables optimized tuning at all boost pressures with ability to safely manage over boost properly. Long term mass flow accuracy, good for emissions equipped vehicles with low horsepower ranges. No limitations on manifold design Disadvantages Changes in Engine efficiency over time are not compensated for in calibration. Oxygen sensors can remedy this with closed loop for street engines. Poor low speed resolution on high output engines.