Patent ID: 7107972

Claim:
A method of supplying compressed induction fluid to an intake manifold of an internal combustion engine of a powered land vehicle, wherein the engine includes a rotatable crankshaft and, when off idle, operates at variable rpm over a rev range, said method comprising the steps of: (a) driving a first supercharger by the crankshaft to compress induction fluid; (b) driving a second supercharger by the crankshaft to compress induction fluid; (c) operating the superchargers at least partially in series so that at least some induction fluid that is compressed by the first supercharger is further compressed by the second supercharger and then supplied to the intake manifold of the engine; and (d) operating the superchargers at least partially in parallel so that at least a portion of induction fluid is compressed by the first supercharger and at least another portion of induction fluid is compressed by the second supercharger and the at least a portion and at least another portion of compressed induction fluid are supplied to the intake manifold of the engine without passing through the other supercharger, said driving steps of (a) and (b) each being performed so that both superchargers are continuously operated by the crankshaft at a substantially constant relative speed to the crankshaft speed during the operating steps of (c) and (d).