On the Powertrain Dynamics Influence on Vehicle Performance: the Differentials

In every driving condition powertrain and vehicle dynamics deeply influence each other. The main role of powertrain influence is played by the differential, which transmit the driving torque with respect to wheel kinematics. Many different solutions have been historically developed from pure mechanical devices (as open, self-locking, torque sensitive and speed sensitive) to semi-active and full-active differentials. The recently developed controlled differentials underlined the importance of a good project and tuning of this component to achieve a good performance of the vehicle, in terms of traction, stability, and, more over, drive “feeling”. This paper tries to cover the lack of present literature to provide analysis tools to be used in the preliminary phase of vehicle project in order to evaluate differential influence on vehicle performance. The speculative conclusions that can be draw are supported through a validated vehicle simulation model [2] integrated with a powertrain model.