X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from EXHUB003-4.exch003intermedia.net ([207.5.74.111] verified) by logan.com (CommuniGate Pro SMTP 5.2.16) with ESMTPS id 3850433 for flyrotary@lancaironline.net; Mon, 14 Sep 2009 08:53:38 -0400 Received-SPF: none receiver=logan.com; client-ip=207.5.74.111; envelope-from=jwhaley@datacast.com Received: from EXVMBX003-5.exch003intermedia.net ([207.5.74.45]) by EXHUB003-4.exch003intermedia.net ([207.5.74.111]) with mapi; Mon, 14 Sep 2009 05:53:00 -0700 From: Jeff Whaley To: Rotary motors in aircraft Date: Mon, 14 Sep 2009 05:53:13 -0700 Subject: RE: [FlyRotary] Re: cockpit soundproofing Thread-Topic: [FlyRotary] Re: cockpit soundproofing Thread-Index: Aco0i1sloU0wGtrYTeiQsFCgSpBTxgArpN5Q Message-ID: References: In-Reply-To: Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: acceptlanguage: en-US Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Aircraft Spruce provides a link to the Sound Proofing "How-to Manual" as we= ll ... http://www.aircraftspruce.com/catalog/appages/soundproofinstall.php Jeff -----Original Message----- From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Beh= alf Of Mike Wills Sent: Sunday, September 13, 2009 11:57 AM To: Rotary motors in aircraft Subject: [FlyRotary] Re: cockpit soundproofing I should have mentioned. My original muffler (which I am reinstalling) had = a=20 turndown of about 20 - 30 degrees. The DNA had no turndown. Again, no=20 detectable difference in noise or performance between the two. Found a how-to from the manufacturer of the black foam Mark and Tracy=20 mentioned here: http://www.soundproofing.org/infopages/soundprf.html Wish I'd installed this stuff in the floorboards before I closed the=20 interior structure. Mike Wills RV-4 N144MW ----- Original Message -----=20 From: "Charlie England" To: "Rotary motors in aircraft" Sent: Saturday, September 12, 2009 1:03 PM Subject: [FlyRotary] Re: cockpit soundproofing > Mark Steitle wrote: >> Mike, >> My first line of defense against the noise is an ANR headset. That's a= =20 >> given. >> I purchased some black foam from ACS that I installed on the interior=20 >> walls and floor. From what I've read a lot of the noise comes in throug= h=20 >> the firewall and windows. Not much you can do about the windows, but it= =20 >> seems that a generous amount of soundproofing on the firewall will help= =20 >> the most. Lastly, you can turn the exhaust down so that it is directed=20 >> away from the occupants? Or, run it back behind the pax, and fly faster= =20 >> than the speed of sound so it can't catch up to you. Mark S. >> >> On Sat, Sep 12, 2009 at 10:15 AM, Mike Wills > > wrote: >> >> I asked a few days ago and got no replies. Since things are a bit >> slow on the list now I'll try again. Anyone have any >> recommendations for a decent soundproofing material that I can add >> to my firewall and floorboards to tame this racket? Maybe the rest >> of the world will have to deal with the noise, but at least I can >> try to make it a little more pleasant for me. >> Mike Wills >> RV-4 N144MW >> >> > Running it back past the occupants can actually be effective. Turning it= =20 > down adds drag. > > I've often wondered why no one has tried carrying the pipes down several= =20 > inches below the fuselage before turning them aft, and installing=20 > streamline inserts aft of the downpipes & between the fuselage bottom &=20 > the horizontal run of pipe, to get smooth air between the fuselage & the= =20 > now-parallel exhaust stream. > > Charlie > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub:=20 > http://mail.lancaironline.net:81/lists/flyrotary/List.html >=20 -- Homepage: http://www.flyrotary.com/ Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.= html