Method and systems for a turbocharger

A method, comprising:

• during a transient event where intake pressure is decreasing, detecting a turbocharger surge event based on a rate of change of the decrease in intake pressure and a rate of change of turbocharger turbine speed;
• storing turbine speed associated with the surge event;
• classifying the surge event based on the associated turbine speed;
• and
• indicating a change in performance of the turbocharger when a number of surge events in one or more classifications reaches a threshold number.

A system, comprising:

• a first turbocharger including a first compressor coupled to a first turbine;
• a second turbocharger including a second compressor coupled to a second turbine, the second turbocharger arranged in parallel with the first turbocharger;
• and
• a controller and sensor system configured to:
• detect a first surge event of the first turbocharger based on a rate of change of intake manifold pressure measured by a sensor and a measured rate of change of turbine speed of the first turbine;
• detect a second surge event of the second turbocharger based on the rate of change of intake manifold pressure measured by the sensor and a measured rate of change of turbine speed of the second turbine;
• store first operational data associated with the first surge event and second operational data associated with the second surge event in memory of the controller;
• indicate a change in performance of the first turbocharger based on a cumulative number of detected first surge events and associated operational data;
• and
• indicate a change in performance of the second turbocharger based on a cumulative number of detected second surge events and associated operational data.