Subject: turbo v supercharger
From: Rotary Engine
Date: 1/28/2006, 7:16 PM
To: AA-me



I think this subject has been discussed before, but I need advice about
whether to turbo or supercharge the 20B on my Velocity XL pusher.  I
have the stock turbo but it seems that a  supercharger would be an
easier install.  On the other hand, a turbo is ultimately more efficient
in not stealing so much horsepower, and is a little more compact
installation.  Bruce T. felt that a supercharger sized for a 4.0 liter
piston engine would do the trick and was preferable to a turbo.   I
have read McInnes' book and attended a Turbo Tom forum (he recommended a
supercharger because of the rotary exhaust temp).  I am only looking for
a light boost, say 4-6 over to give me around 325 HP.  I plan on using
Tracy's redrive.  Anybody have any thoughts on this?

On another subject, I got an N number so that I could insure my project
while it was under construction and within a month I received a friendly
letter from the state division of taxation looking for their piece of
the action!  It turns out that I could have just reserved the N number
and the carrier would still have insured it.  A word to the wise....

jeremy solomon

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The stock 20B dual turbo is definitely unsuitable if for no other reason
it is very very heavy.

With a supercharger 100% of the required HP to drive the
super charger comes from the engine's e-shaft. In effect a 300 HP
net engine is generating 330 gross HP or so. That means there will
be about a 10% increase in fuel burn.

A turbo charger on the other hand gets as much as 90% of its required
HP out of the normally waste energy in the exhaust. The waste energy
amounts to about 50% of each gallon of gas burned in almost any internal
combustion  engine so to use this waste energy to drive the turbo charger
is a very  good idea. You should have only a slight fuel penalty
with a turbo charger and you will be going much faster at altitude.

The exhaust heat will not be a problem is the turbo charger is sized right
and is equipped with a Inconel turbine. Most are.

Paul Lamar ...No rotor no motor.

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