This may be a dumb question, but I was just wondering:

What is the turbo doing when we're not on any boost at all? Nothing? Rotating too slowly to generate any psi?

Mods move to newbie if it is too stupid.

 

It's chilln like a villain. No but really I think that's a pretty good question...

 

Turbo continues to spin just not at a rate high enough to generate boost.

 

Isn't all the turbo doing in essence is sucking in air faster than a n/a engine would.. minus all the other mumbo jumbo?

 

http://auto.howstuffworks.com/turbo.htm

 

Yeah, essentially at idle and relatively low engine speeds there is not enough exhaust gas flowing past the turbine to generate positive manifold pressure(boost). You can tell when the turbo crosses over the boost threshold by watching your boost/vacuum gauge.

A turbocharger may continue spinning even after you've shut the engine off. This is one of the advantages of having a turbo timer since the turbine shaft rides on a thin film of oil which requires a constant, pressurized supply of the lubricant to live.

 

stick your finger in their and find out. lol j/k really you can take your inlet pipe off and look to see what it is doing.

 

Empiricism?

 

Although this link does give a pretty good explanation in this example, there is a lot of misinformation on that website. For example there quiz on engines and explanation of how internal combustion engines work say that the reason a car doesn't start and stop moving is because there are more than one piston firing at different times. Although helpful, this is not entirely true. The reason the engine doesn't start and stop is because the crankshaft mass and flywheel store the kinetic energy and release it as a smoother, rotational force. The engine doesn't stop because those components "carry" it to the next power cycle.

Back on topic, yes the turbo spins however as several have said before, just not fast enough to produce a positive pressure difference. I would highly discourage anyone from putting fingers in the turbo inlet, even at idle there is enough power there to remove chunks from your digits! LOL I've heard of Robert at Forced Performance rebuilding turbo's with bloody damage from just such an event.

Josh

 

LOL same thought process! LOL

Josh