This SAE Recommended Practice provides a standard procedure for testing the output performance and plotting the performance curve of electric starting motors, and a graphical method of determining engine cranking speed.
This guide is intended to cover test procedures applicable to MAP transducers; it is also applicable to transducers such as Barometric (Ambient) Absolute Pressure transducers, Manifold Vacuum transducers, and similar pressure transducers used in automotive systems. Although oriented towards active devices (those using internal signal conditioning), it can be applied to passive devices with minor modifications.
The electrical cranking system components, which include the battery, cables, and cranking motor, must be carefully selected to provide the necessary speed to start an engine under the most severe climatic conditions for which the system is intended. Engine cranking loads increase with cold temperatures, therefore, the initial selection of these components needs to consider low-temperature engine torque requirements. To insure an adequate electrical cranking system is obtained, it is important that proper test procedures are used for obtaining the cranking load requirements of the engine.