X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao104.cox.net ([68.230.241.42] verified) by logan.com (CommuniGate Pro SMTP 5.2.11) with ESMTP id 3412333 for flyrotary@lancaironline.net; Mon, 05 Jan 2009 22:15:19 -0500 Received-SPF: none receiver=logan.com; client-ip=68.230.241.42; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo03.cox.net ([70.169.32.75]) by fed1rmmtao104.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090106031438.AJZ11567.fed1rmmtao104.cox.net@fed1rmimpo03.cox.net> for ; Mon, 5 Jan 2009 22:14:38 -0500 Received: from wills ([68.105.85.56]) by fed1rmimpo03.cox.net with bizsmtp id 03Ea1b00B1CvZmk043EcpH; Mon, 05 Jan 2009 22:14:36 -0500 X-Authority-Analysis: v=1.0 c=1 a=NSHW2kUv_6QA:10 a=Zgn9d7bnwx8A:10 a=Tz4x_yad6FJOFGLt7McA:9 a=L7n8-vvAmo82RfHL-XLyVB3MUTcA:4 a=NAcsVDG84Z4A:10 a=U8Ie8EnqySEA:10 a=h9s5Ru71U4oA:10 a=3oc9M9_CAAAA:8 a=RaKj5uqy8ibtAGgYvJYA:9 a=cBI4hjGGEkM1RdOWX3AA:7 a=Jyx6EnGdBtOHeUG7MUARp4EXsewA:4 a=EzXvWhQp4_cA:10 a=AfD3MYMu9mQA:10 X-CM-Score: 0.00 Message-ID: <005601c96fac$e7961300$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: 20B install issues overcome Date: Mon, 5 Jan 2009 19:14:36 -0800 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0053_01C96F69.D928F8C0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.3138 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.3350 This is a multi-part message in MIME format. ------=_NextPart_000_0053_01C96F69.D928F8C0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable At one point a few months ago I added a SuperTrapp to my existing = exhaust just to see if it would tame it a little. Cost me about 500RPM = on the top end with little or no improvement in the sound output. Mike Wills ----- Original Message -----=20 From: wrjjrs@aol.com=20 To: Rotary motors in aircraft=20 Sent: Monday, January 05, 2009 11:49 AM Subject: [FlyRotary] Re: 20B install issues overcome Earnest, I believe that the SuperTrapp muffler is an example of a band gap = device and it worked well, if properly tuned. I think the large block idea has merit too, but you will have to allow = enough thickness to prevent the tubes that see the exhaust first to = fight the harmonic vibration and heat. Different size diamonds in the = exhaust stream might also help fight harmonics. Bill Jepson -------------------------------------------------------------------------= ----- Get a free MP3 every day with the Spinner.com Toolbar. Get it Now. ------=_NextPart_000_0053_01C96F69.D928F8C0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
At one point a few months ago I added a = SuperTrapp=20 to my existing exhaust just to see if it would tame it a little. Cost me = about=20 500RPM on the top end with little or no improvement in the sound=20 output.
 
Mike Wills
----- Original Message -----
From:=20 wrjjrs@aol.com
Sent: Monday, January 05, 2009 = 11:49=20 AM
Subject: [FlyRotary] Re: 20B = install=20 issues overcome

Earnest,
I believe that the SuperTrapp muffler is an = example=20 of a band gap device and it worked well, if properly tuned.
I think = the=20 large block idea has merit too, but you will have to allow enough = thickness to=20 prevent the tubes that see the exhaust first to fight the harmonic = vibration=20 and heat. Different size diamonds in the exhaust stream might also = help fight=20 harmonics.
Bill Jepson


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