Downsizing the internal combustion engine can reduce the fuel consumption by moving the fuel efficient zones closer to road driving conditions. This can be achieved by turbocharging [1]. A mass air flow ratio of over 80:1 from rated power to idle is typical for gasoline engines, in contrast to the ratio of approximately 6:1 for passenger car Diesel engines [2]. It highlights the demand for varying the characteristics of the boosting systems on gasoline engines [3]. In addition, the transient response of conventional turbocharged gasoline engines is usually slow compared to naturally aspired engines. This is due to the period of time required to accelerate the turbocharger, achieve the target boost pressure, and reach the required engine torque [4, 5]. One of the available boosting systems that have the potential to achieve rapid transient response and high fuel efficiency over a wide flow range is the variable geometry turbine (VGT) turbocharger [3].