Maintaining transient torque response is challenging on turbocharged engines because of the period of time required to accelerate the turbocharger. Variable Geometry Turbine (VGT) turbochargers offer a route to improve the transient response. In order to explore the transient operation without any limitation imposed by the production control strategy, an on line search was conducted using a series of open loop actuator trajectories applied to a VGT turbocharger installed on a gasoline engine. The trade-off between the responses in different stages in the transient event has been illustrated. The time required to reach 50% of maximum torque rise (T50) was improved by up to 0.54s (35.5%) whilst the turbocharger acceleration was maintained. Fully closing the VGT resulted in high exhaust back pressure and low volumetric efficiency.