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Baffle for Open Megaphone with Reverse Cone

Started by SB107, December 07, 2020, 10:56:09 AM

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C-Cat

March 02, 2021, 07:37:25 PM #25 Last Edit: March 02, 2021, 08:00:02 PM by C-Cat
I don't see how the Burns  Baffle can come out, the Supertrapp Baffle can be removed. The collector and muffler is what Vince sent me for the Dyna. I'm going to run the Trapp without discs to start, thinking unrestricted it will he close with my tune. Tech at Supertrapp said the 5in. Doesn't need as many discs as the 4in. Although I bought extras just in case and was going to do washers if it needs more discs ( closed endcap) as you've done, when I can get it to the Dyno. I need to quiet it down for my neighbors and my hearings sake.
Merc 63, went from a Burns to the Supertrapp Muffler on his B2 124 and it actually made peak HP at 6400 from 6000 with the Burns. His advice was not to run the Burns because of the noise and low speed manners compared to the Trapp. He had also tried the discs and his preference was without. With all that said my 124 made 161/145 sae as is, and is a left side dominate curve, which is ok on my Dyna. I do have  a Boarzilla also, but the Dyna Zilla IMO isn't as much pipe as the touring Zilla and will move the TQ left while limiting HP and the front tire will be up in the air a lot more with the TQ coming in early. I'm looking forward to seeing SB 107's and your results, along with my own.
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

kd

March 02, 2021, 09:10:23 PM #26 Last Edit: March 02, 2021, 09:15:11 PM by kd
I think we are all singing out of the same hymn book.  I was fortunate to meet Vince before he took over Burns Stainless and they started to make the No Holds Barred pipe.  I introduced him to a couple of knowledgeable people at SEMA on our first arranged meeting and between everyone settled some of the details. He had the beginnings of a prototype and blended everything together to make a very nice exhaust system that is a top performer (and looks killer). I believe his first pipe went to me and I was able to spec a longer head pipe to pick up the torque it was lacking for a touring bike.  To be clear, the guys using it for track or with lighter bikes did not need the early torque because it supports so much mid to top. I also asked for the longer megaphone.  BTW they now offer a smaller baffle and pipe configuration for less than hi-performance big blocks and others. As you can see if you look up my dyno sheet here, the Dragula 1 one was quite capable with the 2.55 baffle and out performed the Burns at 2500 rpm. I want that back. One of the big reasons I am testing is to get the most out of the pipe without hearing damage and heat from the police (it's becoming a real threat) but also to share it with Vince. He was good to me. With the time it has taken me to complete the machining and with COVID complications holding me back, I would think he's wondering where I have gone.  :unsure:  I also found a great way to mount the longer muffler so it doesn't stress crack by using small brackets they have that I welded in place.  I think there will be more than one way to skin this cat and individual tolerance for the loud Burns muffler will be a huge deciding factor on how to do it.  After all, that's one of the reasons we are doing it.

BTW, SuperTrapp has some great and helpful literature if you care to look for it on line.  I visited their techs at SEMA and they confirmed a lot for me.  The techs that I talked to were great resources thinking out of the box. Also, I have absolutely no slow speed manner issues with the Burns exhaust on the highway, street or parking lot.  I suspect without knowing his engine and gearing specs, Merc 63 may have needed a tune adjustment.
KD

SB107

Quote from: C-Cat on March 02, 2021, 07:37:25 PM
I don't see how the Burns  Baffle can come out, the Supertrapp Baffle can be removed. The collector and muffler is what Vince sent me for the Dyna. I'm going to run the Trapp without discs to start, thinking unrestricted it will he close with my tune. Tech at Supertrapp said the 5in. Doesn't need as many discs as the 4in. Although I bought extras just in case and was going to do washers if it needs more discs ( closed endcap) as you've done, when I can get it to the Dyno. I need to quiet it down for my neighbors and my hearings sake.
Merc 63, went from a Burns to the Supertrapp Muffler on his B2 124 and it actually made peak HP at 6400 from 6000 with the Burns. His advice was not to run the Burns because of the noise and low speed manners compared to the Trapp. He had also tried the discs and his preference was without. With all that said my 124 made 161/145 sae as is, and is a left side dominate curve, which is ok on my Dyna. I do have  a Boarzilla also, but the Dyna Zilla IMO isn't as much pipe as the touring Zilla and will move the TQ left while limiting HP and the front tire will be up in the air a lot more with the TQ coming in early. I'm looking forward to seeing SB 107's and your results, along with my own.

I plan to keep everybody updated as this seems to be an issue for so many. I believe my baffle will also work in the Burns muffler as well (being the perforated tube is only 2.400ish OD). Need to calculate exit area to make sure it will not restrict too much flow. I calculated the area of the old Guppy baffle which has proven to make plenty of power, so as long as I am in that ballpark I should be fine. KD's design does offer tunability and probably a much quieter sound. My version is just simpler, something that will probably cost under $50 all said and done. I am fortunate that my father owns a CNC Lathe/Mill shop so I have material, machines, and his experience at my disposal.
Mutant Motors 124"
161/148 STD, 158/145 SAE

SB107

Old guppy exit area: 4.35sqin
My baffle exit area (no cone): 7.5sqin
my baffle exit area with cone: 4.57sqin

My baffle has nice, gradual angles to keep the flow of the gases relatively smooth, not make them run into a wall (KD gets credit here with his critiquing of my old design)
Mutant Motors 124"
161/148 STD, 158/145 SAE

C-Cat

March 04, 2021, 06:21:39 AM #29 Last Edit: March 04, 2021, 06:28:50 AM by C-Cat
Comparison of muffler bodies and inside baffles.
On a previous post I stated " left side dominate curve" I meant right side obviously.
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

SB107

End cap blanks are done. Tomorrow I will be doing the milling for the cutouts, drilling for the mounting holes, and cutting the perforated tube to length.

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Mutant Motors 124"
161/148 STD, 158/145 SAE

Deye76

East Tenn.<br /> 2020 Lowrider S Touring, 2014 CVO RK,  1992 FXRP

SB107

Quote from: Deye76 on April 07, 2021, 02:11:55 PM
Nice.
Is that ST muff a 4" or 5" ?

I believe somewhere he mentioned it was 5"
Mutant Motors 124"
161/148 STD, 158/145 SAE

SB107

The hard stuff is done. Now just need to put some holes in the muffler and bend the ends of the tubes in.
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[attach=1]
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Mutant Motors 124"
161/148 STD, 158/145 SAE

Fugawee


SB107

Quote from: Fugawee on April 09, 2021, 05:59:33 AM
Nice Work! Look pretty good to Me.   :up:

Thanks, I cant say I came up with the whole design, but I did incorporate a few things I liked from the Guppy Baffle, KW HP Plus baffles, and the BCT Quiet Baffles, as well as No Cents endcap he made. Machining was done on 2 CNCs at my dad's shop. He had his lead man do the blank on a lathe and we went in on a mill to do the cutouts. Turned out awesome, don't even want to put it in the pipe lol.
Mutant Motors 124"
161/148 STD, 158/145 SAE

SB107

While my baffle didn't do much in terms of sound deadening  :emoGroan: I believe it will help my tq dip. I did a roll on pull and noticed it pinged, which made me assume it needs more fuel in the lower RPM range. Dyno will tell us whether or not my hypothesis is correct....
Mutant Motors 124"
161/148 STD, 158/145 SAE

HighLiner

Where did you source that perforated baffle material?

HogMike

April 27, 2021, 04:26:20 AM #38 Last Edit: April 27, 2021, 07:39:00 AM by Coyote
Quote from: SB107 on April 26, 2021, 01:04:19 PM
While my baffle didn't do much in terms of sound deadening  :emoGroan: I believe it will help my tq dip. I did a roll on pull and noticed it pinged, which made me assume it needs more fuel in the lower RPM range. Dyno will tell us whether or not my hypothesis is correct....

Maybe try a louvered baffle instead of the perf style for a better noise reduction? You can get different lengths and diameters from different sources.
Just a thought.
HOGMIKE
SoCal

SB107

Mutant Motors 124"
161/148 STD, 158/145 SAE

HighLiner


C-Cat

Getting this together, I'll report back on noise reduction and seat of the pants comparison. Going to try no Discs at first, or until I can get it to a Dyno
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

kd

May 16, 2021, 06:03:14 AM #42 Last Edit: May 16, 2021, 08:00:17 AM by kd
That looks nice, and you should be able to run 2 tunes when you are done. (with and without discs).

I finally completed my stinger and use 4" SuperTrapp discs with a closed endcap on a Burns 3" baffle. I have been out with it every day and am even enjoying my stereo on the highway. No more ringing ears or need for ear plugs. It's kinda nice not being noticed riding down the street with the exhaust pinging off the buildings.  I got home the other day and here's an unsolicited email I received from a buddy.

"Passed you twice yesterday. Your bike seems quiet. Thought it would be more obnoxious."

I did the calculation on what I needed to maintain the exit size of the Burns megaphone and installed 48 4" discs.  Last year I ran a SuperTrapp open end cap and 26 discs but wasn't much better than wide open. This is where I wanted to be.

Because I made sure I was flowing the same volume for the tune I am riding it.  I have to wait until I can cross the border to my tuner in the Minneapolis area.  I can tell you it seems to hit harder and is raw and brutally hard in the lower gears.  It does bark when you do that but it's to be expected.  :teeth: I am sooooo happy the work to go the extra mile with the design paid off.  I will try to add a pic later.


I think I will find a way to make some C&C copies now.  The fixture I have is aluminum and made with a mounting sleeve to make it adjustable to various muffler exit mounting diameters.  It actually has some internal ported fluting to ensure the flow is not interrupted by any needless flat surfaces intersecting the exhaust gasses. Stay tuned.
KD

C-Cat

I may end up where you're at with the discs. I think none is going to work best with current map. If it's still obnoxiously loud going to try 24 5in. Discs and take it from there, either up or down. ST said I won't need nearly as many of the 5 inch discs. as I would on a smaller muffler. They don't make an open end so for 5 in discs, and the closed endcap is imo the wrong shape just to pop a hole into the closed endcap. It would need to be a big opening not to drastically restrict flow. Keep us posted when you can get it dynoed and let's see some pics.
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

kd

For reference, in the 3" & 4" disc size, SuperTrapp says the open end cap they sell (1.375" dia. & 1.484 sq") is the equivalent of 10-12 discs. They should be able to give you a comparison to that claim if you are using the 5".  I stacked enough on to be equal to the 3" baffle the tune was set for. I even tried #10 lock washers between a couple layers (equals approx 3 discs) but it was counter productive sound wise.   
KD

C-Cat

Going to have a 4inch reverse cone machined to bolt up where the discs go. Muffler body is 4.5 inch same as the Burns, only the Discs are 5in. Same with baffles both are 3 inch  I also have a slip fit instead of welding between collector and muffler which adds a 3 inches to the collector before the muffler. Going to put the noise further behind me. That can always be changed to welded if desired.
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

C-Cat

Need to have some brackets fabbed up. It looks better than I thought it would
124ci. 07 Streetbob 161/145
110ci. '11 Roadglide  129/127

kd

The ID on my burns is about 4.125 at the exit.  The baffle is 3".
KD

kd

May 17, 2021, 03:38:38 PM #48 Last Edit: May 17, 2021, 03:59:09 PM by kd
Here's a quick pic installed.  You can see there's what SuperTrapp calls a heat deflector at the base of the stack of discs. It gathers up the flow out of the first 10 or so discs and forces it to the rear which carries the heat away. Also my primaries are 6 or 8 inches longer than the production Burns No Holds Barred pipe.
KD

SB107

Thanks for sharing the pics, guys!

Quick Story: Was out for a cruise on Sunday, doing my normal riding. Nothing super crazy, few pulls to 5000rpm (about as high as I can spin it without committing a felony). All of the sudden I notice the thunderous rasp on decel again which my baffle took care of. I thought "that's weird, haven't heard that in a while". Get home and my collector is EMPTY, the baffle fell out! I was dumb and forgot I loosely bolted it in and didn't use locktite. Went back to where I noticed the noise come back and in the middle of the road was my perforated tube. Searched 30-40 min for the aluminum piece in 1.5ft grass and couldn't find it. Had dinner with my parents and told them about it and my Mom offered to come out and help me look. Sure as "Potty mouth" within 3 mins she finds it on the side of the road, couldn't believe I missed it...

Luckily the ring wasn't damaged, a few scuffs nothing a file wont take care of. Best believe next time it goes in I'm using locktite....
Mutant Motors 124"
161/148 STD, 158/145 SAE