Fuel Efficiency Improvements from Lean, Stratified Combustion with a Solenoid Injector

In light of the growing emphasis on CO2 emissions reduction, Delphi has undertaken an internal development program to show the fuel economy benefits of lean, stratified combustion with its outwardly-opening solenoid injector in a vehicle environment. This paper presents the status of this ongoing development activity which is not yet completed. Progress to date includes a logical progression from single-and multi-cylinder dynamometer engines to the vehicle environment. The solenoid-actuated injector used in this development has an outwardly-opening valve group to generate a hollowcone spray with a stable, well-defined recirculation zone to support spray-guided stratification in the combustion chamber. The engine management system of the development vehicle was modified from seriesproduction configuration by changing the engine control unit to permit function development and calibration. The resulting full-size, V6-engine vehicle achieves significant fuel savings compared to homogeneous stoichiometric operation, while showing the potential to be the bestvalue Powertrain solution through the innovative use of solenoid injector technology.