Abstract: A multiple stage supercharging system is disclosed suitable for both two-stroke cycle and four-stroke cycle internal combustion engines. Ambient air, which is propelled by the forward velocity of the engine, enters an air cleaner housing (11) through an air filter. The air cleaner housing (11) attaches to the air intake (32) of a centrifugal compressor (12). The centrifugal compressor (12) mounts directly to the magnetic flywheel on the crankshaft of the engine. The centrifugal compressor wheel (22) pressurizes the ambient air for use in the combustion process. The outlet of the centrifugal compressor housing mates with a secondary plenum chamber (17). The outlet of the secondary plenum chamber (17) mates with a d.c. motor driven axial compressor (28). The axial compressor (28) operates on current derived from a motor driven alternator (38). The outlet of the axial compressor connects to a primary plenum chamber (18) which connects to the air intake snorkel on the carburetor.