The reduction of particulate emissions of turbodiesel powered vehicles has limited the amount of fuel that can be injected at low engine speeds. Supercharging under these conditions provides increased air flow, increased BMEP and reduction of smoke. A Sequential Hydro-Supercharging System (SHS) has been developed to provide increased air flow to the engine in a controllable fashion over the engine's entire speed and load ranges. The SHS utilizes two standard turbocharger compressor impellers driven by well proven, miniature, high speed, high efficiency hydraulic turbines. Each of these turbines is capable of producing 10 HP at 70,000 rpm. A complete SHS package suitable for a 230 hp turbodiesel is comprised of two TO4B size hydro-superchargers, two sequential gear pumps, solenoid valves, oil cooler and a 2 liter oil tank. The entire SHS weighs less than 16 kilograms.