Sorry about the stupidity of this question, but i'm fairly new to all this stuff, so i have to ask somewhere

What exactly do superchargers and turbos do?

Thanks for your patience with newbies

 

force air into an engine by mechanical pumping forces

 

So what's the difference between superchargers and turbochargers? anything?

 

one is crank driven and one is driven by exhaust gasses

 

Which is crank driven? and does that make 1 better than the other?

 

superchargers are crank driven and both have advantages and disadvantages, neither makes "more power"

 

they do make the same amount of power that the engine produces. but there is no free energy. one is driven off of the exhaust gases and heat (Turbo). and the supercharger is driven off of the crank. but through the mechanics and stuff there is more parasitic loss on the supercharger thus giving a lower net power.

 

There is no free power, that is true. I'm really sorry but I tried to keep it neutral, I was hoping no one would go there. Considering that both will use power to raise the efficiency of the engine. Most people feel that even with the parasitic losses of a supercharger, it is the better way to go considering the great amount of restriction to the exhaust side caused by a turbo. In actuality both have parasitic losses. The engine is a great big pump, and it sees pumping losses from trying to force exhaust gasses through a restriction. No matter how small it has been made by use of header and how much power it is adding. "You cant get something for nothing" is a saying that holds true for both of these power adders. It comes down to a "6 of one, or half a dozen of the other" situation.

 

the superchargers have better low end torque because of no lag.

 

ahha, right...

Obviously you've never driven a sy/ty or GN. Stock they're all low end. The sy/ty's have a redline in the mid 4K rpm range, and are really done by then.

Where a turbo sees boost is entirely up to the package.

Positive displacement blowers will see boost down low.

centrifical blowers usually don't do much till you've got them really spinning so you won't see anything down low.

 

BTW, what B4Ctom1 said: there is no free power. Period.

You're using up engine power in some form to drive all of these. Whether it's a turbo through exhaust restriction (the restriction adds up to something close to what it would be if it was belt driven, much more in a lot of smaller, more street friendly setups), or a blower sucking the power right off the crank using a belt.

There will be some marginal differences in the efficientcy of converting that power into boost, but for the most part they're relatively similar. For the most part, turbos have a higher adiabatic efficientcy (losses due to adding heat when compressing it), while things like volumetric efficentcy can't really be measured on them (some of the newer postive displacement blowers like the eaton and wipple screw have ve's in the 90-95% range). Of course, there are some frictional losses in all cases also.

Last I heard the wipple screw type blowers are on top wrt efficentcy, but I wouldn't be surprised if the ball bearing turbos are in a similar range.

 

definitons are correct, but i got another one, please, is just info and not trying to be a smartass.
to me is clear that a turbo is a way of force-feeding via a "turbine powered impeller", the limitation being the pressure generated, close to 14psi. or 1 atmosphere, for poor guys like us.
a supercharger is called "super" because will normally feed beyond 1 atmosphere, it could either be with a "turbine" powered impeller or a "mechanical powered impeller.
is hard to imagine, but look at it like this.
put your piston at BDC, squeeze 14psi of mixture, close the valves and move the piston to TDC, can you imagine the compression?, in WW2 was very much used, BUT, very few engines ever made it to the 100hrs, overhaul time.
it was very common to have an engine failure on take-off with the consecuent....
thanks for your time.
Fernando.

 

I'm not sure that I get your question/point.

A supercharger is any pump that can feed an engine more air then it would normally take in normally aspirated.

A turbocharger is just a turbine powered supercharger.

Both can build boost pressures over atmospheric, the only difference is where they get the power to drive the pump/compressor.

WRT the compressor centrifical superchargers and turbochargers are roughly similar (build boost by pushing more air then the engine will take in), where postive displacement superchargers (roots type, screw...) compress the air inside their own housings.

 

This has to do with the stock offset journal crank, and the settings in the code. Went for a ride in "the black car" over the weekend. Holy smokes what a prepped GN can do.

 

this is all nice but a turbo will deliver above 1 atmoshphere