A turbocharger variable speed control mechanism for a turbocharger for an engine includes a sun gear of a planetary gear set coupled to a turbocharger shaft, a planet carrier operatively connected to an engine output shaft of the engine, a brake disk coupled to and rotatable with a ring gear, and a brake actuator mechanism proximate the brake disk and mounted to a turbocharger housing. The brake actuator mechanism is selectively actuatable between a non-braking state where no braking force is applied to the brake disk so that the ring gear is free to rotate relative to the turbocharger housing, and a full braking state where a full braking force is applied to the brake disk such that the ring gear is held stationary relative to the turbocharger housing and rotation of the planet carrier is transmitted through the planetary gear set to cause rotation of the turbocharger shaft.