A method for providing air to a combustion chamber of an engine, the engine including a compressor and a boost tank selectably coupled to an intake manifold. The method comprises admitting air from the compressor to the intake manifold via a main throttle valve, storing some air from the compressor in a boost tank, and discharging some of the air stored in the boost tank to the intake manifold via an auxiliary throttle valve distinct from the main throttle valve.