X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from fed1rmmtao107.cox.net ([68.230.241.39] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3543159 for flyrotary@lancaironline.net; Tue, 10 Mar 2009 22:36:46 -0400 Received-SPF: none receiver=logan.com; client-ip=68.230.241.39; envelope-from=rv-4mike@cox.net Received: from fed1rmimpo02.cox.net ([70.169.32.72]) by fed1rmmtao107.cox.net (InterMail vM.7.08.02.01 201-2186-121-102-20070209) with ESMTP id <20090311023609.WTZM10385.fed1rmmtao107.cox.net@fed1rmimpo02.cox.net> for ; Tue, 10 Mar 2009 22:36:09 -0400 Received: from wills ([68.105.85.56]) by fed1rmimpo02.cox.net with bizsmtp id Rec61b00N1CvZmk04ec9on; Tue, 10 Mar 2009 22:36:09 -0400 X-Authority-Analysis: v=1.0 c=1 a=kviXuzpPAAAA:8 a=pGLkceISAAAA:8 a=BQK-xGKPAAAA:8 a=6iULb4pFhuozKDom8FYA:9 a=qwYODYQ5qj8UthSBHycA:7 a=80tdVel5qvgX5BQDeBiwrErmfs4A:4 a=4E1p6MsWW-gA:10 a=4vB-4DCPJfMA:10 a=MSl-tDqOz04A:10 a=51rXQWSCtg9LVvGX:21 a=dlA-c6KUubepKq67:21 a=Ia-xEzejAAAA:8 a=UretUmmEAAAA:8 a=xmivMW6jzHZX_LP6cxMA:9 a=jqkVGGu3tqiNA3CpGrwA:7 a=qYM-vsxYFvF9nlurd1TYqyLRz3cA:4 a=AfD3MYMu9mQA:10 a=EzXvWhQp4_cA:10 a=iVkDmfvjeKcA:10 X-CM-Score: 0.00 Message-ID: <004201c9a1f2$2107d9d0$38556944@wills> From: "Mike Wills" To: "Rotary motors in aircraft" References: Date: Tue, 10 Mar 2009 19:36:06 -0700 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_003F_01C9A1B7.745CB690" 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 Subject: Re: [FlyRotary] Re: DNA Muffler This is a multi-part message in MIME format. ------=_NextPart_000_003F_01C9A1B7.745CB690 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Agreed Mark. Was just looking for some feedback on that aspect since = your first email focused on the durability side. Thanks for the info and = keep us posted. If it holds up I'll give it a try. Mike ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Tuesday, March 10, 2009 5:57 AM Subject: [Norton AntiSpam] [FlyRotary] Re: DNA Muffler That's true Mike, but the opposite is also true. If it muffles but = doesn't last, it still fails the test. That was the case with the = HushPower II. It muffled great for about 30 minutes, then the guts = oozed out into a puddle on the hangar floor. As for muffling, well, = let's just say that you won't be the stealthiest a/c of the group. But = then my 20B Lancair isn't any louder than an IO-540 powered Lancair, or = so I'm told. =20 When I first installed the DNA "Full Throttle Collector" (DNA p/n = 1040) muffler I was disappointed in its poor muffling qualities. It was = about as loud as the gutted HP II, but at a lower tone and with a very = high-pitched aspect that my Lightspeed ANR headset couldn't cancel out. = Then I remembered what Tracy said about large diameter exhaust pipes = (the DNA muffler that I chose has a 3" inlet & 3" outlet). So, I = purchased a 3" to 2" tapered reducer from Burns Stainless and welded it = onto the outlet. It is surprising how much difference that one small = change made in reducing the noise level. The high-pitched aspect was = now gone and the lower frequencies were noticably reduced. If there was = any loss of power I couldn't tell it. So, out of the box the DNA is too = loud, but with a slight modification, it is very acceptable. =20 My main guage for acceptable exhaust noise is the comments I get from = my hangar neighbors. Early on I used to get lots of "friendly" comments = about how they could hear me coming long before they could see me. Now, = those comments have stopped. They still ask about that "strange = sounding" engine, but only because it sounds different, not because it = is loud enough to break windows for miles around. I'll try to remember = to take some sound level measurements next time I'm out at the airport. = Mark S. =20 On Mon, Mar 9, 2009 at 10:50 PM, Mike Wills wrote: Well, the other big question is does it actually muffle? If the best = thing that can be said about it is that it's surviving I'd be a little = disappointed. I know its hard to judge but how about your opinion = regarding the volume? Thanks, Mike Wills ----- Original Message -----=20 From: Tracy Crook=20 To: Rotary motors in aircraft=20 Sent: Monday, March 09, 2009 8:38 AM Subject: [FlyRotary] Re: DNA Muffler "sounds good" Mark. My guess is that the 2" restrictor is in the = correct place now. Don't think it would be as effective before the = muffler. But the big question is, did the 3 to 2 " reducer cause any = noticeable power loss? I plan to do the same thing on my plane when = time allows. Tracy On Mon, Mar 9, 2009 at 8:08 AM, Mark Steitle = wrote: Mike,=20 It may be a little premature to declare it a winner, but with = ~10 hrs on it now, it is holding up better than anything I've tried so = far. Keep in mind that this is DNA's best muffler, rated for 1000hp. = It is made of fairly thick SS, .030 if I recall, much thicker material = than most mufflers. I had to add a 3" to 2" taper to the outlet in = order for it to be acceptable in the noise category, but that was = surprisingly effective in reducing the exhaust noise to an acceptable = level. (Maybe I should have just put the reducer on the 3" downpipe and = saved some weight.) Anyway, when it passes 25 hours, I'll post another = update. At this time it is looking very promising. Mark S. On Sun, Mar 8, 2009 at 9:20 PM, Mike Wills = wrote: Mark, Any update on the DNA muffler? Mike Wills RV-4 N144MW ----- Original Message -----=20 From: Mark Steitle=20 To: Rotary motors in aircraft=20 Sent: Friday, January 16, 2009 7:05 AM Subject: [FlyRotary] DNA Muffler Does anyone on the list have any real-life rotary experience = with the DNA Gen II muffler = (http://www.dnamufflers.com/DNA/main_DNA.html)? It is an interesting = design in that it has no packing material to burn out. Instead, it = utilizes ladder-rungs, which they call "internal sound diffusers", which = resemble a chain of DNA down through the center of the muffler body, = which is made of 304 SS. Their web site claims that the racers use them = with great success. From speaking with a sales rep, they claim there = the rotary crowd uses them too. I'm considering purchasing one of their = FULL THROTTLE COLLECTOR mufflers (P/N 1040), but thought I would check = to see if anyone else has used this style muffler. This muffler has a = 3" inlet/outlet with a 4" body. So it is compact enough to fit inside = my cowl. My exhaust header has a 3" swivel joint, so it should be a = good fit. =20 Mark S. ------=_NextPart_000_003F_01C9A1B7.745CB690 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable
Agreed Mark. Was just looking for some = feedback on=20 that aspect since your first email focused on the durability side. = Thanks for=20 the info and keep us posted. If it holds up I'll give it a = try.
 
Mike
----- Original Message -----
From:=20 Mark = Steitle=20
Sent: Tuesday, March 10, 2009 = 5:57=20 AM
Subject: [Norton AntiSpam] = [FlyRotary]=20 Re: DNA Muffler

That's true Mike, but the opposite is also true.  If it = muffles but=20 doesn't last, it still fails the test.  That was the case with = the=20 HushPower II.  It muffled great for about 30 minutes, then = the=20 guts oozed out into a puddle on the hangar floor. =  As=20 for muffling, well, let's just say that you won't be the = stealthiest a/c=20 of the group.  But then my 20B Lancair isn't any louder = than an=20 IO-540 powered Lancair, or so I'm told.  
 
When I first installed the DNA "Full Throttle Collector" = (DNA p/n=20 1040) muffler I was disappointed in its poor muffling=20 qualities.  It was about as loud as the gutted HP II, but = at a lower=20 tone and with a very high-pitched aspect that my = Lightspeed ANR=20 headset couldn't cancel out.  Then I remembered what Tracy said=20 about large diameter exhaust pipes (the DNA muffler that I = chose has=20 a 3" inlet & 3" outlet).  So, I purchased a 3" to=20 2" tapered reducer from Burns Stainless and welded it = onto the=20 outlet.  It is surprising how much difference that one small = change=20 made in reducing the noise level.  The high-pitched aspect = was now=20 gone and the lower frequencies were noticably = reduced.  If=20 there was any loss of power I couldn't tell it.  So, out of = the box=20 the DNA is too loud, but with a slight modification, it is very=20 acceptable. 
 
My main guage for acceptable exhaust noise is the = comments I=20 get from my hangar neighbors.  Early on I used to get lots of = "friendly"=20 comments about how they could hear me coming long before they = could see=20 me.  Now, those comments have stopped.  They still ask about = that=20 "strange sounding" engine, but only because it sounds different, not = because=20 it is loud enough to break windows for miles around.  I'll = try to=20 remember to take some sound level measurements next time I'm out at = the=20 airport.  
 
Mark S.    

On Mon, Mar 9, 2009 at 10:50 PM, Mike Wills = <rv-4mike@cox.net>=20 wrote:
Well, the other big question is = does it=20 actually muffle? If the best thing that can be said about it is = that=20 it's surviving I'd be a little disappointed. I know its hard to = judge but=20 how about your opinion regarding the volume?
 
Thanks,
 
Mike Wills
----- Original Message ----- =
From: = Tracy Crook
To: Rotary = motors in=20 aircraft
Sent: Monday, March 09, = 2009 8:38=20 AM
Subject: [FlyRotary] Re: = DNA=20 Muffler

"sounds good" Mark.  My guess is that the 2"=20 restrictor is in the correct place now.  Don't think it would = be as=20 effective before the muffler.

But the big question is, did = the 3 to=20 2 " reducer cause any noticeable power loss?   I plan to = do the=20 same thing on my plane when time allows.

Tracy

On Mon, Mar 9, 2009 at 8:08 AM, Mark = Steitle <msteitle@gmail.com> wrote:
Mike,
 
It may be a little premature to declare it a winner, but = with ~10=20 hrs on it now, it is holding up better than anything I've tried = so=20 far.  Keep in mind that this is DNA's best muffler, = rated for=20 1000hp.  It is made of fairly thick SS, .030 if I recall, = much=20 thicker material than most mufflers.  I had to add a = 3" to=20 2" taper to the outlet in order for it to be = acceptable in the=20 noise category, but that was surprisingly = effective in=20 reducing the exhaust noise to an acceptable level.  (Maybe = I should=20 have just put the reducer on the 3" downpipe and saved some = weight.)  Anyway, when it passes 25 hours, I'll = post another=20 update.  At this time it is looking very promising.
 
Mark S.

On Sun, Mar 8, 2009 at 9:20 PM, Mike = Wills <rv-4mike@cox.net> wrote:
Mark,
 
 Any update on the DNA=20 muffler?
 
Mike Wills
RV-4 N144MW
-----=20 Original Message -----
From:=20 Mark Steitle
To:=20 Rotary=20 motors in aircraft
Sent:=20 Friday, January 16, 2009 7:05 AM
Subject:=20 [FlyRotary] DNA Muffler

Does anyone on the list have any real-life = rotary=20 experience with the DNA Gen II muffler (http://www.dnamufflers.com/DNA/main_DNA.html)?  It is=20 an interesting design in that it has no packing material to = burn=20 out.  Instead, it utilizes ladder-rungs, which they = call=20 "internal sound diffusers", which resemble a chain of = DNA down=20 through the center of the muffler body, which is made of 304 = SS.  Their web site claims that the racers use them = with great=20 success.  From speaking with a sales rep, they claim = there the=20 rotary crowd uses them too.  I'm considering purchasing = one of=20 their FULL THROTTLE COLLECTOR mufflers (P/N 1040), but = thought I=20 would check to see if anyone else has used this style=20 muffler.  This muffler has a 3" inlet/outlet with a 4"=20 body.  So it is compact enough to fit inside my=20 cowl.  My exhaust header has a 3" swivel joint, so it = should be=20 a good fit. 
 
Mark=20 = S.



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