Different approaches are then tested to predict the unsteady turbine behavior, characterized by the measurement of instantaneous pressure data at different stations along the test rig circuit, and the mass flow rate upstream the turbine, as well. With respect to the classical map based approach, a partial improvement is shown if a proper “time delay” pipe is introduced in the schematization. The detailed 1D turbine model based on the sole wheel map indeed produces additional advantages, and reveals the capability to better predict the phasing of the downstream turbine pressure and the amplitude of mass flow rate oscillations. These advantages mainly come out from a more correct computation of the mass and energy storage in the device, realizing a more refined description of pressure waves propagation.