System Description

The turbocharger uses exhaust gas energy from the engine to turn the turbine wheel. The turbine wheel drives the compressor wheel through a common shaft. The impeller on the low-pressure compressor wheel in turn draws intake air through the air filter and inlet plumbing into the compressor housing of the turbocharger. The low pressure turbocharger pressurizes the air and feeds into the high-pressure turbocharger to further pressurize the intake flow. The air is then delivered to the charge-air cooler.

The turbine, compressor wheel, and shaft are supported by two rotating bearings in the bearing housing. Passages in the bearing housing direct filtered, pressurized engine oil to the shaft bearings and thrust bearings. The oil is used to lubricate and cool the rotating components. Oil then drains from the bearing housing to the engine sump through the oil drain connection. An adequate supply of good, filtered oil is very important to the life of the turbocharger.

The compressor bypass valve controls the amount of air that goes into the high-pressure turbocharger. The compressor bypass valve actuator is mounted on the compressor outlet connection, vacuum driven, and controlled by the Engine Control Module (ECM) via the compressor bypass valve solenoid.

TURBOCHARGER BOOST CONTROL OF EACH CONDITION 

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Two Stage 

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Two Stage Modulated 

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Single Stage 

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Wastegate 

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