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Path: utzoo!watmath!watdaisy!gvcormack
From: gvcormack@watdaisy.UUCP (Gordon V. Cormack)
Newsgroups: net.auto
Subject: Re: Superchargers vs. Turbo's
Message-ID: <6691@watdaisy.UUCP>
Date: Sun, 23-Sep-84 23:59:59 EDT
Article-I.D.: watdaisy.6691
Posted: Sun Sep 23 23:59:59 1984
Date-Received: Mon, 24-Sep-84 04:36:57 EDT
References: <231@aesat.UUCP>
Organization: U of Waterloo, Ontario
Lines: 17

Superchargers and turbochargers both use a pump to increase the
pressure (hence amount) of air/fuel going into the engine.  The
only difference is that superchargers are mechanically driven
from the engine, whereas turbos are driven by turbine using exhaust
gas pressure.  Since this energy is normally lost, the turbos run
"for free" but superchargers use useful energy.  Unfortunately, there
is only a lot of exhaust gas flow to drive the turbine when the
engine is already working hard, so there is a positive feedback
problem.  This problem is characterized by a lag and then sudden
onset of power.

In summary, turbos are more efficient but superchargers can give
a much more even boost.

- Gord Cormack, University of Waterloo
 ... watdaisy!gvcormack