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 hollow-cone 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 series-production 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 best-value Powertrain solution through the innovative use of solenoid injector technology.