Why does a naturally aspirated engine make a suction sound when the accelerator is pressed deeply?

[SanCassandra]

It is a normal phenomenon. This is called the natural aspiration vacuum noise of the engine. When the accelerator is pressed deeply, the engine immediately reaches a certain RPM and needs to provide sufficient internal air-fuel mixture. This rapid intake creates a certain degree of vacuum, and this vacuum produces the sound during the process. Working Principle: The working principle is to allow air to enter the combustion chamber under atmospheric pressure without passing through any supercharger, i.e., without a turbo. Natural Aspiration Intake Method: One of the intake methods for naturally aspirated cars is to use atmospheric pressure to push air into the combustion chamber without any supercharger, thereby providing power support for the vehicle.