Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: Systems and methods are provided for reducing surge in a boosted engine system. One method comprises adjusting an opening of a compressor recirculation valve to allow a compressor recirculation flow based on a combination of a nominal compressor recirculation flow and a filtered nominal compressor recirculation flow. The nominal compressor recirculation flow may be calculated as a difference between a desired compressor flow rate based on a surge limit of compressor and an estimated throttle mass flow rate.

Abstract: Systems and methods are provided for reducing surge in a boosted engine system. One method comprises adjusting an opening of a compressor recirculation valve to allow a compressor recirculation flow based on a combination of a nominal compressor recirculation flow and a filtered nominal compressor recirculation flow. The nominal compressor recirculation flow may be calculated as a difference between a desired compressor flow rate based on a surge limit of compressor and an estimated throttle mass flow rate.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, an engine operation is adjusted in response to a turbocharger expansion ratio. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, during a first condition an engine operation is adjusted in response to a turbocharger expansion ratio exceeding a first limit and during a second condition an engine operation is adjusted in response to the turbocharger expansion ratio exceeding a second limit that differs from the first limit. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method and system to control an engine to maintain turbine inlet temperature utilizes two temperature thresholds: a control initiation temperature and a maximum hardware temperature. An engine parameter is adjusted in a closed-loop manner based on an error, which is a difference between a setpoint temperature and the turbine inlet temperature. The setpoint temperature is initially the control initiation temperature. However, after control over turbine inlet temperature is established, the setpoint temperature ramps gradually to maximum hardware temperature. In one embodiment, the engine parameter is engine torque. Other engine parameters affecting turbine inlet temperature include timing and duration of fuel injection pulses, EGR rate, gear selection, and intake throttle position, any of which can be used in place of, or in combination with, torque for controlling turbine inlet temperature.

Abstract: A method for operating a turbocharged engine is disclosed. In one example, an engine operation is adjusted in response to a turbocharger expansion ratio. Degradation of the engine may be reduced under some engine operating conditions by adjusting engine operation in response to the turbocharger expansion ratio.

Abstract: A method and system to control an engine to maintain turbine inlet temperature utilizes two temperature thresholds: a control initiation temperature and a maximum hardware temperature. An engine parameter is adjusted in a closed-loop manner based on an error, which is a difference between a setpoint temperature and the turbine inlet temperature. The setpoint temperature is initially the control initiation temperature. However, after control over turbine inlet temperature is established, the setpoint temperature ramps gradually to maximum hardware temperature. In one embodiment, the engine parameter is engine torque. Other engine parameters affecting turbine inlet temperature include timing and duration of fuel injection pulses, EGR rate, gear selection, and intake throttle position, any of which can be used in place of, or in combination with, torque for controlling turbine inlet temperature.