Abstract: A pressure wave supercharger utilizes a rotor having closely spaced conduits in a rectangular array whose inside surfaces are provided with a catalyst for exothermic oxidation of incompletely burned exhaust gases. The size, geometry and length of the conduits are arranged to achieve maximum energy transfer of the sonic velocity exhaust gases and exothermic expansion of those gases in supercharging incoming air to the intake manifold. The spent gases are discharged to the atmosphere with a minimum of sonic energy.