What is the reason for the air release sound after the turbo kicks in on the Haval H6?

[PeterDella]

Haval H6 turbo kicks in after the air release sound is the sound of the pressure relief valve working, which is a normal phenomenon. Turbo working principle: When the turbo starts working while accelerating, it compresses a large amount of air and pushes it through the throttle into the engine combustion chamber. When the driver releases the accelerator pedal, the throttle closes. However, the turbo blades do not stop working immediately. At this time, there is still residual compressed air in the intake pipe between the turbo and the throttle. If this air is not released in time, the strong pressure can cause damage to the throttle and turbo blades. Function of the pressure relief valve: The valve of the pressure relief valve will release the residual compressed air in the pipe in time when it detects that the air pressure in the intake pipe is too high, thereby protecting the throttle and turbo blades. It also reduces the occurrence of turbo lag, making the engine work more smoothly. The air release sound heard is the "noise" generated when the pressure relief valve discharges the compressed air.