Disclosed is a control system and method for controlling a superturbocharged engine system in various operation modes. Throttle control mode may idle the superturbocharger during low and medium engine loads, so that boost is not created in the intake manifold. During high engine load conditions (open throttle), boosting occurs in response to the driver, operator, or control system requesting increased engine loads. For transient control mode, the control system may respond to transient conditions in response to engine speed and load so that the engine does not bog down or overcome vehicle traction limits. The control system may also predict future operating points.