Abstract: A method for controlling an engine having an intake manifold and an exhaust manifold, where an exhaust gas recirculation path with a valve is provided between said intake and exhaust manifold, and the engine has a turbocharger; the method comprising during at least one decreased engine output condition, increasing opening of the exhaust gas recirculation valve and adjusting exhaust expansion through a turbine of the turbocharger to decrease expansion through the turbocharger and thereby reduce a likelihood of turbocharger surge.

Abstract: A method for controlling an engine having an intake manifold and an exhaust manifold, where an exhaust gas recirculation path with a valve is provided between said intake and exhaust manifold, and the engine has a turbocharger; the method comprising during at least one decreased engine output condition, increasing opening of the exhaust gas recirculation valve and adjusting exhaust expansion through a turbine of the turbocharger to decrease expansion through the turbocharger and thereby reduce a likelihood of turbocharger surge.

Abstract: The present invention is a dual-stage fuel injection strategy for compression ignition engines in which 15-40% of the fuel is injected into the combustion chamber no later than about ?20 to ?30 CA ATDC and as early as IVC. The remaining fuel is then injected in one or more fuel pulses, none of which start before about ?20 to ?30 CA ATDC. The fuel injected early in the compression stroke forms a lean mixture that burns with low soot and low NOx emissions. The combustion of that fuel serves to increase in-cylinder temperature such that the ignition delay of subsequent fuel injection pulses is short. This mode is utilized when it is predicted that a NOx spike is imminent. Various other alternative methods for reducing NOx spikes are also disclosed such as specialized EGR systems that can provide EGR with low manifold vacuum.

Abstract: An exhaust gas purification system for an engine equipped with a turbocharger and an exhaust pipe having a NOx conversion catalyst therein. The system comprises a reservoir for storing pressurized air received from the turbocharger, a reductant injector in fluid communication with a reductant supply, and a mixing chamber in fluid communication with the reservoir and connected to the reductant injector. The reductant injector is responsive to an injection signal for atomizing and injecting a quantity of reductant into the mixing chamber. The mixing chamber is in fluid communication with the exhaust pipe for introducing a quantity of air and reductant mixture into the exhaust gas flow upstream of the NOx conversion catalyst.