A torque control system for regulating operation of a displacement on demand engine that is operable in an activated mode and a deactivated mode includes a throttle that regulates air flow into the engine and a cam phaser that regulates a torque output of the engine. A first module determines a throttle area based on a desired deactivated manifold absolute pressure (MAP) and a desired mass air flow (MAF) and a second module determines a desired cam phaser position based on an engine speed and a transitional air per cylinder (APC) that is determined based on one of a desired deactivated APC and desired activated APC. A third module generates a throttle control signal to control the throttle based on the throttle area and a fourth module generates a cam phaser control signal to control the cam phaser based on the desired cam phaser position.