X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from qw-out-2122.google.com ([74.125.92.27] verified) by logan.com (CommuniGate Pro SMTP 5.2.13) with ESMTP id 3543709 for flyrotary@lancaironline.net; Wed, 11 Mar 2009 11:26:15 -0400 Received-SPF: pass receiver=logan.com; client-ip=74.125.92.27; envelope-from=rwstracy@gmail.com Received: by qw-out-2122.google.com with SMTP id 8so39107qwh.25 for ; Wed, 11 Mar 2009 08:25:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:sender:received:in-reply-to :references:date:x-google-sender-auth:message-id:subject:from:to :content-type; bh=l6wyff2XnetzbrxGR35nodTH6k1NNR+9fGpmjt/r964=; b=AVrpf6vqMe5RSeTDdrhvn4MXAOp0HzKS1bbUqVq5Hcu/5Sp4KkXzJxHW4N+5bfJUkk BweoEGJP5g4yeIOPjvCvVwkE1pXtc+I6AXFYnI5c69546FHv1+xH89L8P/Q63V6OADJH GBkfXR/3ZRXTzHbUZIfl9wH+C9h7UosJp8lkg= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:sender:in-reply-to:references:date :x-google-sender-auth:message-id:subject:from:to:content-type; b=Ojq0imqS7W80WkYd70ki06XTO4EQG5cRCn8IYusrjR5uKwau37ZQ+LNlWgGJxCTrE/ ETWDLqj8oX5ZV0ruLyxPUoARyGiJ07XnsnACADXFqhNHGb0LJ9MIn5ms7pNfySEsTImf aMsNM8+T2N36Cs9Mgoa0Q40LE5RlkMFUZR7ZI= MIME-Version: 1.0 Sender: rwstracy@gmail.com Received: by 10.224.54.138 with SMTP id q10mr11314206qag.220.1236785138376; Wed, 11 Mar 2009 08:25:38 -0700 (PDT) In-Reply-To: References: Date: Wed, 11 Mar 2009 11:25:38 -0400 X-Google-Sender-Auth: 9bacc294e10aea86 Message-ID: <1b4b137c0903110825l4b7242aelc4b0abce83e5b833@mail.gmail.com> Subject: Re: [FlyRotary] Re: DNA Muffler From: Tracy Crook To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=0015175cafbcd61f640464d97a9d --0015175cafbcd61f640464d97a9d Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hmm... I weighed my HushPower II at 8 lbs (with guts :-) I assume at this point (300+ hrs) that mine has lost the fiber packing bu= t the internal baffles are still there. Anxious now to try the outlet neck down to see if it has as much effect on the HP II as Mark's did on the DNA. Tracy On Wed, Mar 11, 2009 at 8:22 AM, Jeff Whaley wrote: > Hi Mark, I was just at the DNA website =85 they don=92t specify weight f= or > any of their products. > > The Hush Power II is about 20 lbs. > > What is the weight of your DNA-1040, Full Throttle Collector? > > Jeff > > > > *From:* Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] *O= n > Behalf Of *Mike Wills > *Sent:* Tuesday, March 10, 2009 10:36 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: DNA Muffler > > > > 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 ----- > > *From:* Mark Steitle > > *To:* Rotary motors in aircraft > > *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 b= e > the stealthiest a/c of the group. But then my 20B Lancair isn't any loud= er > than an IO-540 powered Lancair, or so I'm told. > > > > 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-pitche= d > 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" t= o > 2" tapered reducer from Burns Stainless and welded it onto the outlet. I= t > 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 sli= ght > modification, it is very acceptable. > > > > 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 abo= ut > how they could hear me coming long before they could see me. Now, those > comments have stopped. They still ask about that "strange sounding" engi= ne, > but only because it sounds different, not because it is loud enough to br= eak > 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. > > 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 thin= g > 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 regardi= ng > the volume? > > > > Thanks, > > > > Mike Wills > > ----- Original Message ----- > > *From:* Tracy Crook > > *To:* Rotary motors in aircraft > > *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, > > > > 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 mi= nd > 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 passe= s > 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 ----- > > *From:* Mark Steitle > > *To:* Rotary motors in aircraft > > *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. Inste= ad, > it utilizes ladder-rungs, which they call "internal sound diffusers", whi= ch > resemble a chain of DNA down through the center of the muffler body, whic= h > 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 rota= ry > crowd uses them too. I'm considering purchasing one of their FULL THROTT= LE > 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 wit= h a > 4" body. So it is compact enough to fit inside my cowl. My exhaust head= er > has a 3" swivel joint, so it should be a good fit. > > > > Mark S. > > > > > > > > --0015175cafbcd61f640464d97a9d Content-Type: text/html; charset=windows-1252 Content-Transfer-Encoding: quoted-printable Hmm... I weighed my HushPower II at 8 lbs (with guts :-)=A0
=A0I assume= at this point (300+ hrs)=A0 that mine has lost the fiber packing but the i= nternal baffles are still there.=A0 Anxious now to try the outlet neck down= to see if it has as much effect on the HP II as Mark's did on the DNA.=

Tracy


On Wed, Mar 11, 2009 at 8:2= 2 AM, Jeff Whaley <jwhaley@datacast.com> wrote:

Hi Mark, I was= just at the DNA website =85 they don=92t specify weight for any of their products.

The Hush Power= II is about 20 lbs.

What is the we= ight of your DNA-1040, Full Throttle Collector?

Jeff

=A0

From: Rotary motors in aircraft [mailto:flyrotary@lancaironline.net] On Behalf Of Mike Wills
Sent: Tuesday, March 10, 2009 10:36 PM


To: Rotary motors in aircraft
Subject: [FlyRotary] Re: DNA= Muffler

=A0

Agreed Mark. Was just looking for some feedback on that aspect since your first em= ail focused on the durability side. Thanks for the info and keep us posted. If = it holds up I'll give it a try.

=A0

Mike

----- Original Message -----

Sent: Tuesday, March 10, 2009 5:57 AM

Subject: [Norton AntiSpam] [FlyRotary] Re: DNA Muffler

=A0

That's true Mike, but the opposite is also true.=A0 If it muffles but doesn't last, it still fails the test.=A0 That was the case= with the HushPower II.=A0=A0It muffled great for about 30 minutes, then the guts=A0oozed out=A0into a puddle on the=A0hangar floor. =A0As for=A0muffling, well, let's just say that you won't be the stealthi= est a/c of the group.=A0=A0But=A0then my 20B Lancair isn't any louder than an IO-540 powered Lancair, or so I'm told.=A0=A0

=A0

When I first installed=A0the DNA "Full Throttle Collector" (DNA p/n 1040) muffler=A0I was disappointed in=A0its poor muffling qualities.=A0 It was about as loud as the gutted HP II, but at=A0a lower tone and with a very high-pitched aspect that=A0my Lightspeed=A0ANR headset couldn't cancel out.=A0 Then I remembered what Tracy said about=A0large diameter exhaust=A0pipes (the DNA muffler that I chose has a=A03" inlet & 3" outlet).=A0 So, I purchased a=A03" to 2"=A0tapered reducer=A0from Burns Stainless=A0and welded it onto the outlet.=A0=A0It is surprising how much difference that one small change made in reducing the=A0noise level.=A0 The high-pitched aspect was now gone and the lower frequencies were=A0noticably reduced.=A0=A0If there was=A0any loss of power I couldn't tell it.=A0 So, out of the box the DNA is too loud, but with a slight modification, it is very acceptable.=A0

=A0

My=A0main guage for acceptable exhaust noise is=A0the comments I get from my hangar neighbors.=A0 Early on I used to get lots of "friendly" comments about how=A0they could hear me coming long before they could see me.=A0 Now, those comments have stopped.=A0 They still ask about that "strange sounding" engine, but only because = it sounds different, not because it is=A0loud enough to break windows for mile= s around.=A0 I'll try to remember to take some sound level measurements n= ext time I'm out at the airport.=A0=A0

=A0

Mark S.=A0=A0=A0=A0

On Mon, Mar 9, 2009 at 10:50 PM, Mike Wills <rv-4mike@cox.net> wrote:

Well, the other big question is does it actually muffle? If the=A0best thing that can be said about it is that it's surviving I'd be a little disappo= inted. I know its hard to judge but how about your opinion regarding the volume?

=A0

Thanks,

=A0

Mike Wills

----- Original Message -----

= From: Tra= cy Crook

Sent: Monday, March 09, 2009 8:38 AM

Subject: [FlyRotary] Re: DNA Muffler

=A0

"sounds good" Mark.=A0 My guess is that the 2" restrictor is in the correct place now.=A0 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?=A0=A0 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 <msteitle@gmail.com> wrote:

Mike,

=A0

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 trie= d so far.=A0 Keep in mind that this is DNA's=A0best muffler, rated for 1000hp.=A0 It is made of fairly thick SS, .030 if I recall, much thicker material than=A0most mufflers.=A0 I had to add a 3" to 2"=A0taper= =A0to the outlet in order for it to be acceptable in the noise category, but that=A0was=A0surprisingly effective=A0in reducing the exhaust noise to an acceptable level.=A0 (Maybe I should have just=A0put the reducer on the 3" downpipe and saved some weight.)=A0 Anyway, when it passes 25 hours, I'll post=A0another update.=A0 At this time it is looking very promising.

=A0

Mark S.

On Sun, Mar 8, 2009 at 9:20 PM, Mike Wills <rv-4mike@cox.net> wrote:

Mark,

=A0

=A0Any update on the DNA muffler?

=A0

Mike Wills

RV-4 N144MW

----- Original Message -----

Sent: Friday, January 16, 2009 7:05 AM

Subject: [FlyRotary] DNA Muffler

=A0

Does anyone on the list=A0have any=A0real-life rotary experience with=A0the DNA Gen II muffler (http://www.dnamufflers.com/DNA/ma= in_DNA.html)?=A0 It is an interesting design in that it has no packing material to burn out.=A0 Instead, it utilizes ladder-rungs, which they call "internal sound diffusers",=A0which resemble a chain of DNA down through the center of the muffler body, which is made of 304 SS.=A0 Their web site claims that the racers use them with great success.=A0 From speaking with a sales rep, they claim there the rotary crowd uses them too.=A0 I'm cons= idering purchasing one of their FULL THROTTLE COLLECTOR mufflers (P/N 1040), but thought I would check=A0to see if anyone else has used this style muffler.=A0 This muffler has a 3" inlet/outlet with a 4" body.=A0 So it is compact enough to fit inside=A0my cowl.=A0 My exhaust header has a 3" swivel joint, so it should be a good fit.=A0 <= /p>

=A0

Mark S.

=A0

=A0

=A0


--0015175cafbcd61f640464d97a9d--