SC Question

[33Bravo]

SC Question

As this is my first SC car – I had a general question about how SC work (from a control point of view). Just curiosity..

As the SC is basically a compressor, and is constantly being driven – what is the control mechanism that determines the boost for a given RPM. In other words, where does the boost go at high RPM, and no demand (i.e. deceleration). I know that TC’s can open or close a wastegate, but the SC is always “running”.

Sorry if this is a dumb question… again just curious.

Thanks!

 

[BlackICE]

There is a bypass valve that dump boost whenever there is a vacuum in the intake or if the car is in limp home mode. Other than that the boost is fixed based on the pulley ratio.

 

[Empty Pockets]

Short, non engineering degree answer: The throttle body controls the amount of air allowed into the S/C. So, the air available (and therefore the amount of boost available) in any "part throttle" condition will always be less than at WOT. The boost automatically "goes away" on its own at high RPM as soon as you back off on the "go pedal" 'cause that instantly restricts the air available, and hence, the boost produced.

 

[33Bravo]

Short, non engineering degree answer: The throttle body controls the amount of air allowed into the S/C. So, the air available (and therefore the amount of boost available) in any "part throttle" condition will always be less than at WOT. The boost automatically "goes away" on its own at high RPM as soon as you back off on the "go pedal" 'cause that instantly restricts the air available, and hence, the boost produced.

Makes sense. When throttle body is closed - there really is not much to compress. Knew there was a simple (an elegant) answer.

THanks

 

[Indy GT]

There you go again Pockets, building another "watch".:biggrin
Good answer, by the way....

 

[paul b]

Ah, but after it closes, there's the rub.

 

[Empty Pockets]

There you go again Pockets, building another "watch".:biggrin

Yeah, but I'm only qualified to build a Timex or two. I yield to your own darn self when it comes to throwing together something like a Breguet or Rolex. :bow

 

[Empty Pockets]

Makes sense. When throttle body is closed - there really is not much to compress. Knew there was a simple (an elegant) answer.

THanks

Thank you for asking a question I could actually answer! :lol :cheers