Author Topic: Supertrapp Supermeg 2-1 - how many discs to use?  (Read 1089 times)

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Offline KaritheFinn

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Supertrapp Supermeg 2-1 - how many discs to use?
« on: Monday, July 22, 2013. 12:49:50 PM. »
Greetings.

It looks like I will be getting a brand new chromed Supermeg 2-1 this week to replace the old and rusty SE slip-ons. Which is nice.  :smile:



The Springer is bone stock apart from Stage 1 kit. How many discs would you recommend to use? The exhaust is delivered with just the closed end cap, I believe.
2002 FXSTDI - sold, 2004 FLHRC 124" 148 hp - sold, 1992 FXSTS

Offline Hillsidecyclecom

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #1 on: Monday, July 22, 2013. 03:44:54 PM. »
14-16 disc's would be a great starting point.
Dyno tuning would verify what it'll want.
BTW, those 2/1 Supertrapp pipes are VERY good. :up:
Scott
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Offline KaritheFinn

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #2 on: Monday, July 22, 2013. 11:13:28 PM. »
Scott, thanks for the starting point. :beer:
2002 FXSTDI - sold, 2004 FLHRC 124" 148 hp - sold, 1992 FXSTS

Offline ramcr913

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #3 on: Tuesday, July 23, 2013. 03:18:52 PM. »
14-16 disc's would be a great starting point.
Dyno tuning would verify what it'll want.
BTW, those 2/1 Supertrapp pipes are VERY good. :up:
Scott
:up:
Yep, and while I am no expert I have 2 bikes with Supertrapps. The pipe will *most likely* be delivered with a closed end cap, 20 discs, the muffler pack (ready to install), and the mounting hardware. Start with 15 discs and go from there. And while I haven't dyno'ed mine, Scott is giving you the right advice- a dyno and tune is the only way to squeeze the ponies and ft.lbs out of it. My 80" Evo (woods W6 and Mik 42) wound up with all 20 discs. Still tweaking a 120" Ultima, we'll see where it goes...
Post your results, good luck.

Offline KaritheFinn

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #4 on: Tuesday, July 23, 2013. 09:34:54 PM. »
It may be that it will be installed and adjusted just 'by the ear' at this point. We don't have that much riding season left and there's possibly a set of heads and camshaft coming along in the winter so dyno session would be done then.

I managed to add an open end cap in the same order. It'll be interesting to hear differences in the sound.
2002 FXSTDI - sold, 2004 FLHRC 124" 148 hp - sold, 1992 FXSTS

Offline koko3052

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #5 on: Tuesday, July 23, 2013. 09:47:49 PM. »
Open will be loud if whaling on it! :scoot:

Offline KaritheFinn

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #6 on: Wednesday, July 24, 2013. 12:28:15 AM. »
IIRC I read somewhere that open end cap equals 9...10 discs so that and 4...6 discs could/would/should be the starting point.
2002 FXSTDI - sold, 2004 FLHRC 124" 148 hp - sold, 1992 FXSTS

Offline KaritheFinn

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #7 on: Saturday, July 27, 2013. 11:30:51 AM. »
Installation is almost complete, just need to put the heat shields on tomorrow morning.

I put the closed end cap on with 16 discs and according to a quick test the Supermeg is q-u-i-e-t. Probably will put the open end cap on tomorrow with some 5 discs and go riding. Need to take the earplugs with me just in case.  :smilep:
2002 FXSTDI - sold, 2004 FLHRC 124" 148 hp - sold, 1992 FXSTS

Offline Winston Wolf

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #8 on: Saturday, July 27, 2013. 05:06:05 PM. »
Here is some testing I did on the dyno.  This is with the open end cap, I did not test with the closed cap (I think it sounds way to quiet) 

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Online strokerjlk

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #9 on: Saturday, July 27, 2013. 10:00:09 PM. »
If you use the closed end cap . Put all the disks in .
That will give you the most low end tq.

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Offline JamesButler

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #10 on: Sunday, July 28, 2013. 10:35:57 AM. »
Here is some testing I did on the dyno.  This is with the open end cap, I did not test with the closed cap (I think it sounds way to quiet) 

(Attachment Link)

WW, What build do those Dyno #'s represent?  88" Twin cam?

Offline Winston Wolf

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #11 on: Sunday, July 28, 2013. 06:45:04 PM. »
Here is some testing I did on the dyno.  This is with the open end cap, I did not test with the closed cap (I think it sounds way to quiet) 

(Attachment Link)

WW, What build do those Dyno #'s represent?  88" Twin cam?

Yes,  It is a 95" Twin Cam.  Also, the Supertrapp has been modified a bit. (see below) The megaphone was shortened to about 10", and half of the internal perforated baffling was covered to make it louder.  But, you get the idea on what kind of changes the discs will make to the torque curve.

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« Last Edit: Sunday, July 28, 2013. 06:47:14 PM. by Winston Wolf »

Offline JamesButler

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Re: Supertrapp Supermeg 2-1 - how many discs to use?
« Reply #12 on: Monday, July 29, 2013. 07:01:25 AM. »


"Yes,  It is a 95" Twin Cam.  Also, the Supertrapp has been modified a bit. (see below) The megaphone was shortened to about 10", and half of the internal perforated baffling was covered to make it louder.  But, you get the idea on what kind of changes the discs will make to the torque curve."



Yes, if I'm reading correctly, I see that the torque curve increases slightly with more discs (at least until up to 20).

Another thought:  With a modified motor, it would seem best to run an open-end cap, in order to better purge the extra heat which would be produced.
« Last Edit: Monday, July 29, 2013. 07:04:12 AM. by JamesButler »