Actually, A turbocharger, besides usually being exhaust driven, uses vaned wheels to move a large volume of air, usually working at very high speeds. The centrifugal action of the wheel creates the flow or pressure similar to the way a centrifugal pump works. Superchargers are usually rotary screw or lobe pumps, belt driven. The major significance is that they are positive displacement pumps. Even the VW G-Ladder is a PD pump. They need to be belt driven since as a PD pump, if it is not turning, air will not flow through it.

Dennis

----- Original Message -----
From: Jeffrey Schwaia <jeff@VANAGONPARTS.COM>
Date: Thursday, September 29, 2005 1:57 pm
Subject: Re: yet another engine choice - VW "twincharger"

> Re: yet another engine choice - VW "twincharger"Right and wrong.  A
> turbocharger is a supercharger, however, it gets it name from the
> fact that
> it uses a turbine to spin the compressor.  The turbine is spun via
> exhaustgases.
>
> Cheers,
>
> Jeff
>
>  -----Original Message-----
>  From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On
> Behalf Of
> Andrew Grebneff
>  Sent: Thursday, September 29, 2005 12:22 AM
>  To: vanagon@GERRY.VANAGON.COM
>  Subject: Re: yet another engine choice - VW "twincharger"
>
>
>    Turbos can be driven by exhaust (almost all), belt (Paxton) or
> electricmotor (as VW was paying Mitsubishi to research in the 90s).
>
>
>  Turbos in their early days (WW2) were called turbosuperchargers.
> Unfortunately, with the contraction to turbocharger, it's "outta
> sight,outta mind"... take super out and soon people forget that it
> IS a
> supercharger.
>