Abstract: A hydraulic drive assists to increase the acceleration rate of a turbocharger impeller/turbine shaft assembly and provide a secondary means of driving the compressor impeller at lower engine speeds where exhaust gases alone does not generate adequate shaft speeds to create significant induction boost. The hydraulic circuit includes a dual displacement motor, which provides high torque for acceleration yet converts to a single motor for high-speed operation. When the exhaust driven turbine function allows compressor speeds, beyond which the hydraulic system can contribute, a slip clutch allows disengagement of the hydraulic drive. The hydraulic circuit is integrated with the power steering circuit to conserve energy and supportive components such as lines and reservoir. In an alternative embodiment, there is no turbocharger and the hydraulic drive provides means of forced induction air alone.