Baffle for Open Megaphone with Reverse Cone

[SB107]

So, after 1 quick trip with the new build I decided it needs to be toned down. I've seen the pictures of the guppy baffle, so using that idea and simplifying it I came up with this. I will be wrapping it with muffler packing. My muffler is slightly different than No Cent's muffler, because it its an open megaphone with reverse cone, so I think its required that I use some sort of muffler packing.

Right now the wrapped portion is a Ø2.900" OD perforated tube (designed to fit in a 3" dia 18ga tube). It is roughly 8" long. Thinking the 8" might be a little too long, maybe I'll shorten it to 6".

Should I go down to a 2.5" dia perforated tube? 2" dia? Not looking to really pick up too much low end just want to tame it down a notch (or 5) for my sanity any any poor soul that rides behind me.

The endcap that the perforated tube mounts to will be machined. Would like to keep it simple so I can knock it out on an engine lathe and a mill. I could drill holes in it (the endcap) to allow more flow as well.

Any suggestions or ideas would be appreciated. Thanks.

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[kd]

IMO that baffle will be wagging like a dog's tail in there.  I built an endcap for my 3" burns similar to No Cent's and added a modified SuperTrapp disc silencer on the end. I am confident it will easily flow more than the 3" baffle in the Burns megaphone. I did this to reduce the sound level but not at the expense of power.

Full disclosure though, I completed it the month COVID hit and have not been able to get across the border to get it re-tuned properly. I can not compare it to the original tune. The silencer has been manually tuned to be soot free and the tune installed is working well.  If you like, you can PM me with your email address and I will share a few pics with you.   

[HighLiner]

Interesting ideas.  I have a Burns muffler similar to your description having nothing inside and I was told it can't have a baffle added.

[kd]

If you look into the rear you'll notice a perforated skin layer.  That's a baffle.  If it's the original offering I have found it'll likely be 3". They do offer other options now.  The 3" is actually a straight through baffle.      I know, it doesn't really baffle too much. That's why I set out to build a tunable stinger / silencer for it.

[SB107]

Interesting ideas.  I have a Burns muffler similar to your description having nothing inside and I was told it can't have a baffle added.

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Like this?

I wanted to try to do a 3" baffle like I had modeled, the guppy one obviously makes power but as kd stated it would probably move around a lot. Maybe I could wedge it in before tightening so it seats inside the muffler?

I do really like the idea of the disks though. I think it would be no issue going straight to an open endcap. My cam doesn't want to peak until 4500 anyways.

[kd]

Yep, no baffle in there.  That must be one ear drum splitting loud mother of an exhaust.  Using an end cap will definitely change the characteristics of that muffler and tame down the volume.   Expect it to pick up considerably on the left side for an increase in torque.  You will need to get it on a dyno to do it properly.  My goal with discs was to tune mine to best torque without negatively influencing top rpm right side power. 

[SB107]

Yep, no baffle in there.  That must be one ear drum splitting loud mother of an exhaust.  Using an end cap will definitely change the characteristics of that muffler and tame down the volume.   Expect it to pick up considerably on the left side for an increase in torque.  You will need to get it on a dyno to do it properly.  My goal with discs was to tune mine to best torque without negatively influencing top rpm right side power.

Absolutely, it is brutal loud even with a full face.

I think we will actually tune the exhaust on the dyno, adding disks and see how we can manipulate the tq curve. I think that would be a very fun project/

[kd]

      The closest tuner I trust is 9 hrs away and in the US (MN).  I haven't been able to cross the border since March so I am at a temporary standstill.

[HighLiner]

Exactly the same one I have.  I'll be watching for results!

[C-Cat]

My Burns megaphone has the 3in. scrabble Baffle. You can look down the megaphone and see the primary tubes pretty much the same as the one pictured above. IMO the baffle doesn't do much for sound deadening. Winter now, although i put a few hundred miles on it and like already mentioned "too damn loud".
Going to try a Supertrapp 5in. muffler on it (not cheap in stainless) without the discs and end cap at first.
Merc63 posted his 124 B2 build on here a few years back, he had good results replacing the Burns with the Supertrapp without any discs. I think if you go discs, it will take quite a few to not limit upper rpm power.

[FXDBI]

My Burns megaphone has the 3in. scrabble Baffle. You can look down the megaphone and see the primary tubes pretty much the same as the one pictured above. IMO the baffle doesn't do much for sound deadening. Winter now, although i put a few hundred miles on it and like already mentioned "too damn loud".
Going to try a Supertrapp 5in. muffler on it (not cheap in stainless) without the discs and end cap at first.
Merc63 posted his 124 B2 build on here a few years back, he had good results replacing the Burns with the Supertrapp without any discs. I think if you go discs, it will take quite a few to not limit upper rpm power.

I played with a 5in supertrapp muffler ran all the discs and endcap and played with hole in the middle of the end cap and played with the hole size , Buddy is using it on a 117 now.  Bob

[C-Cat]

Merc63 said he tried the discs, but thought it was limiting upper end power and was easier to tune. Baddyna is also running a Supertrapp with no discs on a 124 and he said better low end TQ with the discs, but lost some upstairs. They both said it's a tolerable noise level even without the discs.

[FXDBI]

Merc63 said he tried the discs, but thought it was limiting upper end power and was easier to tune. Baddyna is also running a Supertrapp with no discs on a 124 and he said better low end TQ with the discs, but lost some upstairs. They both said it's a tolerable noise level even without the discs.

Like I said I ran all the discs and put a hole in the end cap. Started @ 1.5 in  and used a cone stone to open it up . Did this is small increments until it had no top end loss and still had bottom end torque.  I really liked how it sounded, has a real awesome sound behind buddies 117.  I played with the discs and end cap on and off, found this to work the best of both worlds.  Have a fuel moto E-pipe now and couldnt be happier.   Bob

[SB107]

With a lot of good ideas from kd, I have a part I will program on a CNC that will allow me to tinker and do a few iterations to see which one proves superior. I think I can pick up 20ftlbs at 3k, still pull 150+ hp, as well as cut the drone out. I don't need the tq but I think it will be a byproduct of the sound cancellation coupled with pressure wave tuning capability.

[kd]

No Cents and Strokerjk have already proven that was possible on a dyno with Ray's 124 by working the center hole size out slowly without using discs and stopped like FXDBI when the top started to show a shift. I believe 20# is possible and maybe more depending on how the actual pipe is performing with the cams and there is adequate intake to carry it. I forget what Ray and Jim got back. Maybe even more up top is available for the same reasons.  You should also be able to shave off torque in exchange for power at the top.  All this with noise (drone) abatement.  I believe this kind of win / win has enough value to justify the cost of a fixture (which will not be low) when weighed against benefit as mentioned.

[SB107]

Here is an updated part that I designed to avoid using a CNC, as my free CNC shop is going gangbusters right now so we wont have a chance to get it set up. I think we will make 2 versions, one with the annular holes and one without and dyno them back to back. I can also open up the ID of the cone on the back side of the baffle for some potential tunability. I can also use this design and bolt in an off-the- shelf baffle to test it out (fuel moto tunable inserts come to mind). I shortened it up so there wouldn't be as much "wagging" going on. Baffle is 2.5". Thoughts?
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[kd]

I think 2.5" will be about right depending on engine size and output.  A big block looking to produce all the way up will need the annular holes.  The Dragula 2.5" works well with my 120 but the Burns 3" tops it by 5 / 5 staring at 4,000 rpm. The Burns comes off the bottom lower though.  Both are loud getting on it and on the highway you should be wearing ear plugs.  Forget the stereo.

[SB107]

I think 2.5" will be about right depending on engine size and output.  A big block looking to produce all the way up will need the annular holes.  The Dragula 2.5" works well with my 120 but the Burns 3" tops it by 5 / 5 staring at 4,000 rpm. The Burns comes off the bottom lower though.  Both are loud getting on it and on the highway you should be wearing ear plugs.  Forget the stereo.

I'm hoping the angle on the cone in the back and the angle of the cap itself will help break up the sound waves enough to kill drone. I think this is a good way to go but I might try to close up the end where the cone is and see what happens. Should be a fun project, trying to keep it simple and light.

[kd]

Worth trying.  I'm not talking about "drone" though. I mean all out too loud to hear over in my experience.  My ears are ringing after running any distance at highway speed without ear plugs.

[SB107]

Worth trying.  I'm not talking about "drone" though. I mean all out too loud to hear over in my experience.  My ears are ringing after running any distance at highway speed without ear plugs.

You're talking about your 3" baffled meg right?

[kd]

Both. The Dragula too. I have the Burns toned down (with about 24 discs / open end cap) and to about the same level as the Dragula right now (maybe better).  Next is more discs and a closed endcap. It (Dragula) may have been quieter when new but I bought it used from a member here that IIRC wanted something with more bark.    I am not an old fogie when it comes to pipes but they are over the top for any duration.

[SB107]

Both. The Dragula too. I have the Burns toned down (with about 24 discs / open end cap) and to about the same level as the Dragula right now (maybe better).  Next is more discs and a closed endcap. It (Dragula) may have been quieter when new but I bought it used from a member here that IIRC wanted something with more bark.    I am not an old fogie when it comes to pipes but they are over the top for any duration.

This thing is so intense the sound resonates in your head. Even with a full face and ear plugs. Just want to get rid of the resonation (drone) and as a byproduct tq will improve. If it only makes 150hp I wont be upset.

[kd]

I can't imagine living with an empty megaphone.  We'll compare notes later.  I'm waiting on extra ST discs and the closed endcap.  Hopefully I will be able to get across the border to my tuner soon.

[C-Cat]

At idle the Burns muffler isn't bad, as soon as you put load on the engine it's too much noise to be going down the road and also for me.I got a 5 in. Supertrapp Muffler and 24 discs to try. The Supertrapp will put the noise further behind me and with a longer baffle,  fiberglass matting instead of the Scrabble in the Burns 3 in. Baffle I think it will have more sound deadening and back pressure than the Burns even without the Discs. Going to experiment with it until I can get it to a Dyno. The Supertrapp has a 4 5 muffler body and 19in. long compred to 12in. Length on the Burns  , 3in. Baffle only the discs and endcap are 5in.
https://photos.app.goo.gl/c1327FHWoTsWiAcU7

[kd]

Your system is very short. My Burns is 22" long overall including the collector, 16" of it being the actual megaphone body. It ends 2" past the rear axle on my touring 2011 RGU.  I had the head pipes made 6" (8"?) longer to pick up some torque.  I am using 4" discs which start out with the SuperTrapp heat shield directing the flow back. I have 24 discs on it right now with the first 3 discs (under the heat shield) spaced with one #10 lock washer for each layer. With the discs it ends 3.5" past the rear axle. I only had 24 discs and wanted to be sure I wasn't causing a rich burn. A spaced disc equals 3 discs.  All this with the ST open course open end cap. The ST open end cap equals 10 to 12 discs. Technically, I am now at about 36 to 38 discs with washers. If it had a closed end cap and no washers I could need as many as 40 discs .  I am presently using the tune I have for the Dragula 1 2.55 baffle   The pipe is not sooted up or burning too clean. I have more discs on the way along with a closed end cap.  When (if COVID restrictions lift), I can get across the border to my tuner south of Minneapolis / St Paul (border closed for over a year now) we will tune it for the open and closed end cap.  I already have the raw open Burns "as it comes" and Dragula tune.  I expect more than 1 day on the drum. It will be expensive but I am confident I have it right. It is set up with 18 and 12mm bungs and we use sniffer tube to confirm also so I expect the tune will be exact.  The tuner is a known excellent tuner.  It's a TTS Master Tune device. My goal includes making it more tolerable and also picking up the left side torque to match the 130+ I now get at 2500 rpm.  Another HTT member (NoCents) here has proven the torque rise can be done with a different fixture. I am shooting for that but a little quieter.

I would be surprised if you could change the baffle material.  Isn't yours welded in?

[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.

[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.    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.

[SB107]

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.

[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)

[C-Cat]

Comparison of muffler bodies and inside baffles.
On a previous post I stated " left side dominate curve" I meant right side obviously.

[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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[Deye76]

Nice.
Is that ST muff a 4" or 5" ?

[SB107]

Nice.
Is that ST muff a 4" or 5" ?

I believe somewhere he mentioned it was 5"

[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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[Fugawee]

Nice Work! Look pretty good to Me.   

[SB107]

Nice Work! Look pretty good to Me.   

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.

[SB107]

While my baffle didn't do much in terms of sound deadening  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....

[HighLiner]

Where did you source that perforated baffle material?

[HogMike]

While my baffle didn't do much in terms of sound deadening  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.

[SB107]

Where did you source that perforated baffle material?

LA Choppers

[HighLiner]

Where did you source that perforated baffle material?

LA Choppers

Thanks.  I thought it looked the same.

[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

[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.  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.

[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.

[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.   

[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.

[C-Cat]

Need to have some brackets fabbed up. It looks better than I thought it would

[kd]

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

[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.

[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....

[Hossamania]

That's funny! Moms just have that ability to find things.
The baffle flew out of my Thunderheader somewhere. Hope it didn't hurt anybody.

[kd]

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....

I use Neversieze.  It prevents galling of the aluminum threads and pulls it down tight. The difference is I tighten mine.    A couple of checks after it get hot and it will be snug each time you check after.  You don't have to over do it either.

[SB107]

That's funny! Moms just have that ability to find things.
The baffle flew out of my Thunderheader somewhere. Hope it didn't hurt anybody.

I don't know how I missed it. First trip up the road about 50ft from where we parked she found it. Luckily it fell out on a road not heavily travelled, I like to stay off the main roads for safety reasons and to make sure I can have some fun without the police being called.

[C-Cat]

I use Neversieze.  It prevents galling of the aluminum threads and pulls it down tight. The difference is I tighten mine.    A couple of checks after it get hot and it will be snug each time you check after.  You don't have to over do it either.


Good advice 👍

[kd]

I use Neversieze.  It prevents galling of the aluminum threads and pulls it down tight. The difference is I tighten mine.    A couple of checks after it get hot and it will be snug each time you check after.  You don't have to over do it either.


Good advice 👍

2nd year w/ no issues and the threads are still minty.  (touch wood    )   That includes the discs as per SuperTrapp's recommendations.  They have been removed and adjusted many times but still require the check over a few times before they are seated.   

[C-Cat]

That's funny! Moms just have that ability to find things.
The baffle flew out of my Thunderheader somewhere. Hope it didn't hurt anybody.

I don't know how I missed it. First trip up the road about 50ft from where we parked she found it. Luckily it fell out on a road not heavily travelled, I like to stay off the main roads for safety reasons and to make sure I can have some fun without the police being called.

Had my  helmet blow off my head at 75moh and accelerating. It landed in the woods after bouncing off the pavement. I made a guesstimate and found it in 5 minutes. Pure luck!

[bump]

I had the coil cover fall off my shovelhead while going about 60mph. I found it at next stop light in town. It was stuck in grill of pickup truck behind me. 

[SB107]

Had my  helmet blow off my head at 75moh and accelerating. It landed in the woods after bouncing off the pavement. I made a guesstimate and found it in 5 minutes. Pure luck!

I had a metal detector with me and was determined to find it. I was hoping both pieces fell out at the same time. Going to use some red threadlocker on it next time it goes back in and actually tighten it. Might put something else on it to make sure the nut doesn't fall off even if it comes loose.

My Thunder Torque insert came in the mail. Stuffing that in the perforated tube to see what it does to the sound. Hoping I wont have to wrap it.

[kd]

Owen, I would reconsider the thread locker.  It seems that you will be experimenting more.  You may be flinching now and be sorry later.  Think about the hundreds of thousands of mufflers out there with exhaust tips on them and none of them use thread locker. All you have to do is remember to tighten it and check it a few times after it's heat cycled.    I'm not sure where you are using nuts as fasteners but you can always use locking type with the crimped crown (non nylon).  You may be over thinking it.   Just sayin.   

[SB107]

Owen, I would reconsider the thread locker.  It seems that you will be experimenting more.  You may be flinching now and be sorry later.  Think about the hundreds of thousands of mufflers out there with exhaust tips on them and none of them use thread locker. All you have to do is remember to tighten it and check it a few times after it's heat cycled.    I'm not sure where you are using nuts as fasteners but you can always use locking type with the crimped crown (non nylon).  You may be over thinking it.   Just sayin.   

KD, I am an engineer, my job is to overthink!! LOL Yes they don't use thread locker however they are not subject to the same environments as these. The nuts hold the perforated tube to the fixture and the fixture to the exhaust tip. I went this route for simplicity's sake. I don't care what it looks like as the only people who are going to see it are the ones that line up next to me. (hopefully C-Cat lives far far away...)

[kd]

Owen, I would reconsider the thread locker.  It seems that you will be experimenting more.  You may be flinching now and be sorry later.  Think about the hundreds of thousands of mufflers out there with exhaust tips on them and none of them use thread locker. All you have to do is remember to tighten it and check it a few times after it's heat cycled.    I'm not sure where you are using nuts as fasteners but you can always use locking type with the crimped crown (non nylon).  You may be over thinking it.   Just sayin.   

KD, I am an engineer, my job is to overthink!! LOL Yes they don't use thread locker however they are not subject to the same environments as these. The nuts hold the perforated tube to the fixture and the fixture to the exhaust tip. I went this route for simplicity's sake. I don't care what it looks like as the only people who are going to see it are the ones that line up next to me. (hopefully C-Cat lives far far away...)

Well as an engineer, (by the way I love your drawings) you have seen my fixture and you are the only one to have personal knowledge of my total finished design.  You're use of nuts is probably a choice I would make too. Kill 2 birds with one stone. 

I'm sorry, but I fail to see how your system is not subject to the same environment.  In some ways it is more extreme with the closed end cap and that stack of stainless discs hanging off the back.  My  fixture is a 2 piece base, yours is 2 piece in total.  I have discs and end caps (up to 49 extra pieces) and you don't.  I am capturing heat, you are releasing it.  I have used never seize on all fasteners after deep discussions with a SuperTrapp "engineer" at a SEMA booth.  It actually gets the fasteners tighter with less stress on the threads.  I used reasonable practices as you would when you install a new set of exhaust gaskets and after 3 checks with minor snugging of the fasteners after heat cycles found them to be tight from that point on.  When I wanted to remove them, within 1/2 turn they would literally spin out with a screw driver.  All of them. 

This is not theory, it's practical experience over a couple of years of use without failure.  Just trying to help but I can step back and see what I can learn from you.     I have achieved my goals now, (provided I can get on a dyno and confirm the power and tune safety - damn COVID - border is closed another month now).  It sounds great, is super tolerable and almost pulls the bars out of my hands when I hit it hard in the first 3 gears. I love the smell of burning rubber curling over my shoulders when it breaks loose.   

[SB107]

Owen, I would reconsider the thread locker.  It seems that you will be experimenting more.  You may be flinching now and be sorry later.  Think about the hundreds of thousands of mufflers out there with exhaust tips on them and none of them use thread locker. All you have to do is remember to tighten it and check it a few times after it's heat cycled.    I'm not sure where you are using nuts as fasteners but you can always use locking type with the crimped crown (non nylon).  You may be over thinking it.   Just sayin.   

KD, I am an engineer, my job is to overthink!! LOL Yes they don't use thread locker however they are not subject to the same environments as these. The nuts hold the perforated tube to the fixture and the fixture to the exhaust tip. I went this route for simplicity's sake. I don't care what it looks like as the only people who are going to see it are the ones that line up next to me. (hopefully C-Cat lives far far away...)

Well as an engineer, (by the way I love your drawings) you have seen my fixture and you are the only one to have personal knowledge of my total finished design.  You're use of nuts is probably a choice I would make too. Kill 2 birds with one stone. 

I'm sorry, but I fail to see how your system is not subject to the same environment.  In some ways it is more extreme with the closed end cap and that stack of stainless discs hanging off the back.  My  fixture is a 2 piece base, yours is 2 piece in total.  I have discs and end caps (up to 49 extra pieces) and you don't.  I am capturing heat, you are releasing it.  I have used never seize on all fasteners after deep discussions with a SuperTrapp "engineer" at a SEMA booth.  It actually gets the fasteners tighter with less stress on the threads.  I used reasonable practices as you would when you install a new set of exhaust gaskets and after 3 checks with minor snugging of the fasteners after heat cycles found them to be tight from that point on.  When I wanted to remove them, within 1/2 turn they would literally spin out with a screw driver.  All of them. 

This is not theory, it's practical experience over a couple of years of use without failure.  Just trying to help but I can step back and see what I can learn from you.     I have achieved my goals now, (provided I can get on a dyno and confirm the power and tune safety - damn COVID - border is closed another month now).  It sounds great, is super tolerable and almost pulls the bars out of my hands when I hit it hard in the first 3 gears. I love the smell of burning rubber curling over my shoulders when it breaks loose.   

I am talking about off-the-shelf muffler end caps, not your fixture. They are not subject to direct exhaust flow like our systems are. Just a little confusion, we're on the same page. I'm saying that the muffler end caps have the exhaust flow consistent through the middle, and our systems are in the direct path of the exhaust flow and have larger surface areas.

[kd]

Well, my last comment on the subject is IMO, they are. If you look at enough of them you will see what I mean.  I have spun several speed nuts trying to remove them when they weren't lubed. But I've been around for a while too.       Put a few long days on the slab and tell me they don't get just as hot.  In fact, SuperTrapp sells a a bolt in fixture with an open or closed endcap.  They call them "tunable spark arresters" with the closed cap for off road.  Same thing, different sales pitch.  As for the larger surface, it probably benefits as a heat sink through the area of contact at the mounting surface to the pipe.

[Just Nick]

Very Nice Design I have a couple Guppy pipes and baffles that work great but I am on the other side of the spectrum as you, I want it louder I am in the beginning stages of designing my own baffle also I will share when I am at that point. I have just made my own pipe and a couple others for customers bikes also once I get time to get my own bike on the dyno I will be testing a few different baffles and merge collectors I have made with 12 or 15 degree bends going into the mega cone and post pictures. Another good supplier of perforated tube is Beverlin specialty tube, I am getting some 3.5" perf from then soon with 65% open factor to build another baffle. I am running a 3.5 inch reverse cone at the exit but I have a 4" exit I need to polish out a cone to weld up to and test that one on my new motor I just finished building in my dyna.     all my picture are on my phone so I will post them when I get a chance if anyone is interested.  Its funny that I have not been here for a couple years and the first post I see when I jump back on is this one and I going through the same process as you are too it must be a sign   

[C-Cat]

I think we are all interested, please share.

[98fxstc]

Very Nice Design I have a couple Guppy pipes and baffles that work great but I am on the other side of the spectrum as you, I want it louder I am in the beginning stages of designing my own baffle also I will share when I am at that point. I have just made my own pipe and a couple others for customers bikes also once I get time to get my own bike on the dyno I will be testing a few different baffles and merge collectors I have made with 12 or 15 degree bends going into the mega cone and post pictures. Another good supplier of perforated tube is Beverlin specialty tube, I am getting some 3.5" perf from then soon with 65% open factor to build another baffle. I am running a 3.5 inch reverse cone at the exit but I have a 4" exit I need to polish out a cone to weld up to and test that one on my new motor I just finished building in my dyna.     all my picture are on my phone so I will post them when I get a chance if anyone is interested.  Its funny that I have not been here for a couple years and the first post I see when I jump back on is this one and I going through the same process as you are too it must be a sign 

Good to have you back Nick

[SB107]

Very Nice Design I have a couple Guppy pipes and baffles that work great but I am on the other side of the spectrum as you, I want it louder I am in the beginning stages of designing my own baffle also I will share when I am at that point. I have just made my own pipe and a couple others for customers bikes also once I get time to get my own bike on the dyno I will be testing a few different baffles and merge collectors I have made with 12 or 15 degree bends going into the mega cone and post pictures. Another good supplier of perforated tube is Beverlin specialty tube, I am getting some 3.5" perf from then soon with 65% open factor to build another baffle. I am running a 3.5 inch reverse cone at the exit but I have a 4" exit I need to polish out a cone to weld up to and test that one on my new motor I just finished building in my dyna.     all my picture are on my phone so I will post them when I get a chance if anyone is interested.  Its funny that I have not been here for a couple years and the first post I see when I jump back on is this one and I going through the same process as you are too it must be a sign 

This is what we need, another guy with the same problem whos actively searching for a solution. What a great asset this site is.

I added a Thunder Torque insert into my perforated tube. No noticeable difference in volume at idle, but it sounds deeper and much less racket on decel and cruising volume is less. I really like the way it sounds but I think I'll need packing if I want to make it much quieter. I may call it quits now as after actually riding the bike the loud exhaust isn't as bothersome as I had originally thought.

Also yes, I'm sure we are all very interested in what you're willing to share!

[C-Cat]

Did the insert alter the torque curve? As in earlier Torque or limit topend? I know sometimes it's hard to gauge or even find the right place to get a couple good blasts through a few gears.

[kd]

When No Cents did his it was on the dyno.  The way he explained it he started out with a reduced exhaust hole and was able to open up the fixture slowly until the top end looked like it was ready to drop. IIRC that gave him a huge left side lift without compromising the top on the right side.  The seat of the pants dyno will be tough to gauge where your at.

[C-Cat]

Just did a 70 mile ride 92*. I was getting used to the Burns Megaphone. Bike is running sweet, although I must admit now that I'm relaxing my ears are fricken ringing. Got a new SE 502 180 on the back and fixed the small leak at my shifter. Time to get the mounts for the Supertrapp fabbed up. Absolutely no heat issues with the headpipes compared to the Boarzilla.

[Hossamania]

Do you ride with earplugs?

[kd]

Very Nice Design I have a couple Guppy pipes and baffles that work great but I am on the other side of the spectrum as you, I want it louder I am in the beginning stages of designing my own baffle also I will share when I am at that point. I have just made my own pipe and a couple others for customers bikes also once I get time to get my own bike on the dyno I will be testing a few different baffles and merge collectors I have made with 12 or 15 degree bends going into the mega cone and post pictures. Another good supplier of perforated tube is Beverlin specialty tube, I am getting some 3.5" perf from then soon with 65% open factor to build another baffle. I am running a 3.5 inch reverse cone at the exit but I have a 4" exit I need to polish out a cone to weld up to and test that one on my new motor I just finished building in my dyna.     all my picture are on my phone so I will post them when I get a chance if anyone is interested.  Its funny that I have not been here for a couple years and the first post I see when I jump back on is this one and I going through the same process as you are too it must be a sign 

This is what we need, another guy with the same problem whos actively searching for a solution. What a great asset this site is.

I added a Thunder Torque insert into my perforated tube. No noticeable difference in volume at idle, but it sounds deeper and much less racket on decel and cruising volume is less. I really like the way it sounds but I think I'll need packing if I want to make it much quieter. I may call it quits now as after actually riding the bike the loud exhaust isn't as bothersome as I had originally thought.

Also yes, I'm sure we are all very interested in what you're willing to share!

FWIW I can now do highway and around town trips listening to my stereo.  My 3" Burns is now super tolerable and have received comments on how good it sounds. The best part is how much I like the sound.

[C-Cat]

Do you ride with earplugs?

no

[Hossamania]

Do you ride with earplugs?

no

Helps cut down on ringing from wind and exhaust. It also preserves your hearing for later in life.

[C-Cat]

 

[Hossamania]

Do you ride with earplugs?

no

Helps cut down on ringing from wind and exhaust. It also preserves your hearing for later in life.

Too late?

[C-Cat]

If you're asking, my hearing isn't good. Next long ride I'll be wearing them. I wore them last year, unless I wasn't going far. It will be quieter when I swap the muffler out

[Hossamania]

If you're asking, my hearing isn't good. Next long ride I'll be wearing them. I wore them last year, unless I wasn't going far. It will be quieter when I swap the muffler out

[SB107]

I have a dyno session planned for July 9th. Also have an old style guppy on the way from a friend to compare it to.

[98fxstc]

I have a dyno session planned for July 9th. Also have an old style guppy on the way from a friend to compare it to.

Will be an interesting comparison
Hope it ticks the boxes for you

[SB107]

Will be an interesting comparison
Hope it ticks the boxes for you

He told me the guppy was quiet. If mine compares in performance I might leave it in. Trying to talk him into selling it to me.

[C-Cat]

that will be an interesting comparison.  Do you have forward controls?

[SB107]

that will be an interesting comparison.  Do you have forward controls?

No I have mids. With my current bars forwards would be dangerous with this power lol

[C-Cat]

I was going to have a Guppy made for my Dyna. I was told by Brian Trusdale only with Forward Controls.

[SB107]

I meant old style guppy baffle

[C-Cat]

I have a dyno session planned for July 9th. Also have an old style guppy on the way from a friend to compare it to.

Did you get to do a comparison on the Dyno? I've ben riding mine around with earplugs. Much easier on the ears. I have to say I'm missing the Boarzilla exhaust as far as  general riding and having power everywhere. The big primaries/collector and short pipe do make great peak power, although you really need to be on your game shifting quickly not to drop rpm's and staying off the limiter. Not easy with such a peaky pipe. I'm definitely gaining on it. Going to finish the summer out with this and in the spring get to a dyno and try out the supertrapp muffler with longer collector. I do have a Boarzilla on hand if I decide  to run it.

[SB107]

Did you get to do a comparison on the Dyno? I've ben riding mine around with earplugs. Much easier on the ears. I have to say I'm missing the Boarzilla exhaust as far as  general riding and having power everywhere. The big primaries/collector and short pipe do make great peak power, although you really need to be on your game shifting quickly not to drop rpm's and staying off the limiter. Not easy with such a peaky pipe. I'm definitely gaining on it. Going to finish the summer out with this and in the spring get to a dyno and try out the supertrapp muffler with longer collector. I do have a Boarzilla on hand if I decide  to run it.
[/quote]

No. I doubt I will get a change to run the guppy baffle in it but oh well. I bought a piece of tubing to use but my calipers were set with a different zero which I didn't notice until I turned the ID way too big.

We were letting it idle before we changed the oil and the pipe broke where the trans bracket was welded on. The trans bracket was too thick (1/2"), and the weld was absorbing all of the vibration. The fabricator knew exactly why it broke the minute he saw it, and has a plan to fix it correctly as well has support the meg. Before it was just welded to the front head pipe 

[attach=0,msg1392676]

[C-Cat]

 :I'm going to give mine a good look over now. That sucks

[SB107]

About a year later my bike is on the dyno. picked up 10-15ftlbs between 2500 and 4000, and only lost around 3hp. Ill post up the gains in my thread in dyno charts.