Abstract: A method for operating an engine system is provided. The method includes during a first condition, flowing exhaust gas from a first exhaust gas conduit to a first turbine inlet of a turbine and flowing exhaust gas from a second exhaust gas conduit to a turbine bypass conduit and during a second condition, flowing exhaust gas from the first exhaust gas conduit to the first turbine inlet and exhaust gas from the second exhaust gas conduit to a second turbine inlet.

Abstract: Systems and methods are disclosed for a turbocharger compressor, the system comprising: an actuatable annular disk comprising choke slots therein; an outer annular disk comprising choke slots therein; and an actuator to rotate the actuatable annular disk relative to the outer annular disk to vary alignment of the choke slots of the actuatable annular disk and the outer annular disk. The actuator may be controlled by an engine controller responsive to operating conditions of the compressor and actuated to align choke slots. Alignment of the choke slots allows air to be drawn into the impeller effectively expanding the compressor flow capacity to prevent compressor choke.