Q:

Why do I need to evaluate vehicles and/or tune vehicles under steady-state test conditions?

  A:

Any dynamometer testing application that involves proper testing of a vehicle’s engine must be done with an absorption (steady-state) dynamometer utilizing an electronic torque transducer.  This includes but is not limited to any tuning application.  The reason for this can be attributed to the engine dynamics; each design has its own preordained, speeds-specific output calibrations. In order to adjust or tune the engine, one must be able to control the speed and load imposed on the same.  To further complicate matters, most areas of the world maintain a fairly diverse, heterogeneous vehicle population with each vehicle having its own particular nuances.  The dynamometer must be readily adaptable to different types of vehicles.

An engine cannot be evaluated under various user-defined throttle positions and/or at user-defined speeds without the aid of an active loading mechanism equipped with a torque sensor and an industrial-quality load controller.  Moreover, normal operating conditions cannot be duplicated nor meaningful data collected from areas such as exhaust temperature, lambda, manifold pressure, etc. without the aid of an absorption dynamometer – which allows the dynamometer to load the vehicle long enough for the inputs to stabilize.