X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from m12.lax.untd.com ([64.136.30.75] verified) by logan.com (CommuniGate Pro SMTP 5.1c.2) with SMTP id 1319004 for flyrotary@lancaironline.net; Thu, 27 Jul 2006 20:07:38 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.136.30.75; envelope-from=alwick@juno.com Received: from m12.lax.untd.com (localhost [127.0.0.1]) by m12.lax.untd.com with SMTP id AABCNUXJKAPRV3TJ for (sender ); Thu, 27 Jul 2006 17:06:33 -0700 (PDT) X-UNTD-OriginStamp: L941HVjjYzDhN3itp//mkNliQM/1vNhiUe1f4hVPqBS/7KpMWsH85A== Received: (from alwick@juno.com) by m12.lax.untd.com (jqueuemail) id LWBV9JPT; Thu, 27 Jul 2006 17:05:21 PDT To: flyrotary@lancaironline.net Date: Thu, 27 Jul 2006 16:49:50 -0700 Subject: Re: [FlyRotary] Re: Inconel Message-ID: <20060727.170411.2340.15.alwick@juno.com> X-Mailer: Juno 5.0.33 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Juno-Line-Breaks: 3-4,6-10,12-15 From: al p wick X-ContentStamp: 4:6:2712269114 X-MAIL-INFO:453f83ab9a3a8a8b73c75f4f736e871e5b0e0f27436b270f X-UNTD-Peer-Info: 127.0.0.1|localhost|m12.lax.untd.com|alwick@juno.com Definitely Ernest. The pipe length also determines which frequency it responds to. So if section of pipe is resonating at your normal cruise rpm, there are all sorts of simple things you can do to alter the frequency response. Like adding a weld where one is not needed. I'd sure give consideration to ways of altering response, but I bet there's lot's of substance to temperature and alloy theories too. -al wick On Thu, 27 Jul 2006 11:20:11 -0400 Ernest Christley writes: > Knowing the > flash rate that the muffler is vibrating would easily lead to it's > natural frequency...which could then be used for some effective > muffler designs?