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<DIV><FONT face=Arial size=2>I've been using Karls exhaust diffuser since spring
of 2005 on my Webra 160.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My setup -</FONT></DIV>
<DIV><FONT face=Arial size=2>Webra 160 MC, Asano pipe, S&W 15/17/2
(nitro/synth/castor), 15.75-10 3 blade ~8200 RPM. A 12 oz tank is plenty
for a full F3A schedule, and in calm air I can fly 2 complete schedules on one
tank (about 14-15 minutes of air time). The smoke trail behind my plane is
not a thick and visible as many other planes - mostly because the mixture is
very close to perfect across the throttle range with the MC carb, and low rate
of fuel consumption.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>What I noticed when I added the exhaust diffuser -
</FONT></DIV>
<DIV><FONT face=Arial size=2>- very slightly quieter</FONT></DIV>
<DIV><FONT face=Arial size=2>- very slightly different tone</FONT></DIV>
<DIV><FONT face=Arial size=2>- noise was less directional (ie, more constant in
rolling manuevers)</FONT></DIV>
<DIV><FONT face=Arial size=2>- on days when the smoke trail was very visible,
the exhaust diffuser definitely reduced the smoke trail - mostly through the
midrange, but also a little bit at full throttle.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>My setup is very quiet and smooth sounding without
the exhaust diffuser, and the diffuser makes it just a little bit better.
If used on a plane with lots of prop noise or airframe rattles, I suspect the
improvement in exhaust sound quality may not be audible above the other
noises.</FONT></DIV>
<DIV><FONT face=Arial size=2></FONT> </DIV>
<DIV><FONT face=Arial size=2>Regards,</FONT></DIV><FONT face=Arial size=2>
<DIV><BR>Dave Lockhart</DIV>
<DIV><A href="mailto:DaveL322@comcast.net">DaveL322@comcast.net</A></DIV>
<DIV></FONT> </DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=kgamueller@rogers.com href="mailto:kgamueller@rogers.com">Karl G.
Mueller</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">NSRCA Mailing List</A> </DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 17, 2005 4:34
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> Re: [NSRCA-discussion] How to
minimize exhaust trail?</DIV>
<DIV><BR></DIV>
<DIV><FONT size=2>Glen,</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Here is what I use. It does disperse the smoke a certain
amount, just</FONT></DIV>
<DIV><FONT size=2>getting away from the heavy concentrated stream. It also
changes the</FONT></DIV>
<DIV><FONT size=2>exhaust noise. Dave Lockhart tried one and he claims that it
reduces</FONT></DIV>
<DIV><FONT size=2>the noise by maybe 1db and makes it more non-directional.
This is</FONT></DIV>
<DIV><FONT size=2>noticeable in rolling maneuvers when the exhaust is pointing
at you</FONT></DIV>
<DIV><FONT size=2>or away from you.</FONT></DIV>
<DIV><FONT size=2>The amount of smoke does depend on the climatic
conditions as well.</FONT></DIV>
<DIV><FONT size=2>Some days you will have more smoke showing, especially
against a</FONT></DIV>
<DIV><FONT size=2>nice blue sky while on other days, against a </FONT><FONT
size=2>hazy background, it will</FONT></DIV>
<DIV><FONT size=2>not be as visible.</FONT></DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2></FONT> </DIV>
<DIV><FONT size=2>Karl G. Mueller<BR><A
href="mailto:kgamueller@rogers.com">kgamueller@rogers.com</A><BR></FONT></DIV>
<BLOCKQUOTE
style="PADDING-RIGHT: 0px; PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: #000000 2px solid; MARGIN-RIGHT: 0px">
<DIV style="FONT: 10pt arial">----- Original Message ----- </DIV>
<DIV
style="BACKGROUND: #e4e4e4; FONT: 10pt arial; font-color: black"><B>From:</B>
<A title=gwatson11@houston.rr.com
href="mailto:gwatson11@houston.rr.com">Glen Watson</A> </DIV>
<DIV style="FONT: 10pt arial"><B>To:</B> <A
title=nsrca-discussion@lists.nsrca.org
href="mailto:nsrca-discussion@lists.nsrca.org">nsrca-discussion@lists.nsrca.org</A>
</DIV>
<DIV style="FONT: 10pt arial"><B>Sent:</B> Saturday, December 17, 2005 1:50
PM</DIV>
<DIV style="FONT: 10pt arial"><B>Subject:</B> [NSRCA-discussion] How to
minimize exhaust trail?</DIV>
<DIV><BR></DIV>
<DIV class=Section1>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Dear
list,<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial">Anyone using a diffuser, if that
is the correct term to use, at the end of a muffled pipe to minimize/cloak
the visual effect of the exhaust trail? I am interested in knowing
what you used and if it is commercially available or homemade and how
effective it worked. <o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"><o:p> </o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Regards,<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial">Glen
Watson<o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial color=navy size=2><SPAN
style="FONT-SIZE: 10pt; COLOR: navy; FONT-FAMILY: Arial"><A
href="http://www.geocities.com/rcprecision/pah.html">http://www.geocities.com/rcprecision/pah.html</A><o:p></o:p></SPAN></FONT></P>
<P class=MsoNormal><FONT face=Arial size=2><SPAN
style="FONT-SIZE: 10pt; FONT-FAMILY: Arial"> <o:p></o:p></SPAN></FONT></P></DIV>
<P>
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