Patent ID: 6481425
Filing Date: 2002-11-19
Classification: F02B,F02D,F02M,Y02T

Abstract:
An air supply for a gasoline direct injection engine comprising:a main air supply line communicating with a source of air, said source of air passing through an enlarged volume plenum to a main supply passage, said main supply passage for communicating with an engine chamber; a bypass air supply passage communicating with a source of clean air, said bypass air supply passage for communicating with the engine chamber without passing through said enlarged volume plenum; a valve for being controlled by an engine control, said valve being operable to selectively open said bypass passage to provide additional air to the engine chamber; and a first relatively low air/fuel ratio is utilized at early stages of injection, and a higher air/fuel ratio is utilized at later stages of injection, and said bypass being closed at said early stage of injection, with said bypass valve being opened during a transition period at which the engine is moving from said early injection to said late injection stage.