Turbo Questions
 

For all you forced induction freaks, I've got a quick question:

A turbo works by receiving exhaust gases, which cause the impeller (or turbine, I can't remember) to turn, which then forces air into the intake, right?

So, does that mean that the turbo is directly hooked up to the intake as well?

And lastly, after the exhaust gases spin the turbine, they exit through the downpipe and into the main exhaust pipe, right?

Thanks for the clarification help-

CTB

the turbo uses the exhaust flow to spin the TURBINE, which then spins an air pump. This compresses the air coming in from the intake.

here's a site about turbos...Turbo's!

hope that helps!:bounce:

Another cool website, full of lots of info:

howstuffworks.com

Thanks fellas

I would love to shoehorn Tragerr's duel turboed 3.4 engine into my engine bay :xmas7:

Re: Turbo Questions
 

Yes, the turbo is connected to the intake.

Yup, right again.

A centrifugal blower works the same way except a belt turns the intake turbine instead of the exhaust turning it. Now that I mentioned it,....hmmm.....I wonder......

I was checking out that Turbocharger description that paddlenbike posted and I noticed there is an actuator on it. What's that for? Is that what operates the waste gate?

Well, have fun. :)
DH6twinotter

Corky Bell wrote a great book on turbocharging and design in general (manifolds, intakes, turbocharger sizing, EFI, carbs).

Turbine side or "hot side" of the turbo drivers the power output which is derived from the exhaust energy (flow) from the engine.
Turbine largely determines the high end output power and spool characteristics.
Spool is largely associated with A/R (area to radius ratio) on the hot side.
Don't be fooled by the myth that that big turbos automatically have major lag. If you have a small hot side, you will have less lag, but you'll have less power potential on the high end. It's a trade off with forced induction.
*Turbochargers (~70%) are way more efficient than superchargers (~50%) and can be sized to have very little lag.

The compressor side of the turbo compresses the intake air and sends it to your intake/throttle body or intercooler (if one is used to cool the intake charge). The limitations of the compressor are expressed in the compressor map where you will see it's efficiency range with respects to air flow and absolute pressure ratio. Once the compressor is out of the efficiency range, power will be less since it'll generate more heat.


The acutator you see in the diagram is used to control the wastegate since the turbo in the picture uses an integrated (or internal) wastegate. The wastegate is used to control the boost by opening up at a determined level and fluctuating to maintain or control the level of boost based on pressure signal (between compressor outlet and throttle body) and manifold vacuum.
The spring tension will determine the least amount of boost the wastegate will open as well as the smoothness of fluctuation as it controls boost (i.e. boost creep or spike is bad and signs of an inadequate spring or boost controller).

J