How do engines with forced induction create vacuum?

Question

I’m specifically focused on how engines with centrifugal supercharger create vacuum at the manifold when the engine in high RPM with low load.
Let’s say engine is at 4K RPM with 20% throttle, how can the manifold have a vacuum?

In: Engineering

Answer 1

Usually, closing the throttle body to its idle position will allow the running engine to create vacuum in the intake manifold.