The present invention relates to a turbocharged internal combustion engine (ICE) system having fast response to increased power demand and reduced response time lag. The system includes a vortex tube for delivering cold air into the turbocharger compressor where it may be used to cool the impeller, and/or accelerate the impeller rotational speed, and/or favorably shift the compressor surge line at low speeds and high loads. Cold air from the vortex tube may be also used to operate an ejector pump in the intake duct which further compresses intake air and increases engine charge weight during periods of high power demand. In addition to increasing engine output power, delivery of cold air into engine intake also reduces engine pre-ignition (knocking) thereby reducing emissions. The invention also relates to a method for operating a turbocharged internal combustion engine.