In this work, a systematic approach is developed to calibrate a feedback controller for boost pressure control of an electrically assisted turbocharged gasoline engine. The information from the experiments indicates the system can be approximated by a Gain-Integrator-Delay (GID) model which can be robustly identified. Two controllers are designed for two different types of inner loop control (torque/speed) of the electrically assisted turbocharger. The underlying calibration methodology is based on Internal Model Control (IMC). The application of IMC leads to controllers that can be naturally mapped to a classic feedback controller. The plant model is obtained by characterizing the boost system with relay feedback experiments. The calibration methodology as well as the controller designs are demonstrated with a validated simulation platform and good performance is observed.