The mass air flow harness allows for various means of calculating the mass air flow into the engine. The method used on our crate engines is Speed Density. The ECM uses engine speed, intake air temperature, and manifold air pressure to calculate the amount of air going into the engine. The modular mass air flow harness will allow for a variety of Mass Air Flow sensor to be used in the future. This includes the newest Mass Air Flow sensor that sends a pulse width modulated signal to read air flow and air temperature.