Because loss due to slippage occurs in purely hydrodynamic transmission systems, controlling and regulating these hydrodynamic processes represent a crucial factor for converter efficiency, in addition to a high-performance converter lock-up clutch.
Torque converters from ZF feature optimum hydrodynamic efficiency. The lock-up clutch, a rigid connection between the impeller and the turbine rotor, ensures that the slippage of the hydrodynamic operation is eliminated and that engine power is transmitted to the drive train without any loss. Maintaining efficiency in this way at higher rpm levels helps to reduce fuel consumption. However, a closed lock-up clutch no longer features the outstanding vibration damping properties of a hydrodynamic system – this task can be performed instead by a torsional damper tuned to the requirements of the respective powertrain.