Turbocharger Description and Operation

This engine is equipped with dual turbochargers. Each turbocharger is provided with its own solenoid controlled vacuum-actuated wastegate and recirculation valve. These valves are used to manage the engine's boost pressure and torque response for consistent performance across the RPM band. The wastegates regulate the boost pressure of the engine by providing a bypass path for the exhaust to flow around the turbine wheel back into the exhaust stream to maintain optimal turbine speed. The vacuum-operated wastegate valves provide consistent boost control, particularly at lower engine speeds, to enhance low-speed torque. They are independently controlled on each engine bank to balance the compressors' output to achieve more precise boost pressure response. The wastegates also work in conjunction with the recirculation valves to eliminate compressor surge and excessive noise and vibration from the turbos immediately after the throttle closes. The compressors draw air directly from the inlet box and send pressurized air across the intercoolers (charge air coolers). A single, centrally located throttle body, located under the intercooler cover, controls the air charge from both turbochargers after the temperature is reduced by the intercoolers. This design results in more immediate torque response, for a greater feeling of power on demand. The turbochargers are mounted to the exhaust manifold of each bank and are driven by the energy generated by the flow of the exhaust gases. The turbines are connected by a shaft to the compressors which are mounted in the induction side of the engine.

The turbochargers are connected to the engine oiling system by a supply and drain pipe. The oil is required for the bearing system function and also serves to carry away excessive heat. Each turbocharger is also provided with a coolant circuit, from the engine cooling system, to further reduce operating temperature and passively dissipate bearing housing heat away on shut down.