Insufficient airflow: If the airflow to the turbocharger is restricted, it can cause the air to surge back and forth between the compressor and the turbine. This can happen due to a blocked air filter, clogged intercooler, or other restrictions in the intake system.
Too much airflow: Similarly, if too much airflow is supplied to the turbocharger, it can also cause surging. This can occur if the throttle is rapidly opened or if the wastegate is stuck open.
Mismatched components: If the turbocharger is not properly matched to the engine, it can also lead to surging. For example, a turbocharger that is too large for the engine can produce too much boost, which can cause the air to surge back and forth.
Turbine-inlet nozzle geometry: The design of the turbine-inlet nozzle can influence the onset of surge. In general, wider inlet nozzles are more prone to surge than narrower nozzles.
Compressor and turbine efficiencies: The compressor and turbine efficiencies of the turbocharger also play a role in surge initiation. A low-efficiency compressor or turbine can increase the probability of surge.
Pressure ratio: The pressure ratio of the turbocharger affects surge potential. Turbochargers with high-pressure ratios are more likely to surge than those with low-pressure ratios.
