How to open BMW m4 exhaust valve?

When the turbocharger works, it will open, and then adjust the pressure. When the high-load throttle suddenly closes, it will open, which is all opened by vacuum suction. The sound after opening is louder than the left exhaust sound, especially during cold start. Exhaust valve is a valve used to separate exhaust gas from turbine in turbocharged engine system. The separation of exhaust gas correspondingly reduces the turbine speed and compressor speed. The main function of the exhaust valve is to stabilize the propulsion pressure of the turbocharger system to protect the engine and turbocharger. The exhaust valve is controlled by the exhaust valve actuator, and the rotating device is controlled by the intake manifold pressure. From the appearance, the overall mechanism design is like a simple throttle valve, on which a butterfly valve and a vacuum actuator can be seen. The valve can be opened and closed by the suction of engine vacuum. As long as the valve is installed in the proper position in the exhaust pipe system and the switch timing is used correctly, the engine can have balanced torque and horsepower performance.