Turbo question

I’m new to the turbo scene and I’m curious if the turbos are always spinning when the engine is running. My truck has a gauge and it only shows psi when I give it decent gas. If the truck is parked and idling are they still spinning as well

 

Yes, the turbos are spinning any time the engine is running. They don't build significant boost until the RPMs are over 1500ish.

 

There’s two main parts to a turbo.
The turbine
The compressor

the exhaust spins the turbine. The turbine spins the shaft. The shaft spins the compressor.

with enough load on the engine the exhaust comes out with enough force to spin the turbine hard enough to cause the compressor to push more air than the engine would normally ingest. This is ‘boost’

at light loads true turbine basically free spins.

here’s something fun to do. From an idle stomp the throttle to the floor for half second. Then kill the motor and run to your turbo. Put your ear to it and hear the turbine/ compressor wheels free spin. It does this with my comp oiless turbo. Not sure if a journal turbo would do this.

 

That would seem like there are 3 important parts... The shaft is always important!!!

...sorry I couldn't help myself!

 

That’s what she said?