Muffler Tech?

Discussion in 'Some Assembly Required' started by kellymac530, Feb 20, 2013.

  1. kellymac530

    kellymac530 motorcycle addict

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    Got it now...I am stir crazy...but I have been just crazy for a long time now and I have the perscriptions and doctors note to prove it...:lol3

    On top of just being crazy...I have been just riding the couch for 3 months now...my head is about to explode.

    I had not thought about just running a cat. How loud would you say it is compared to a full stock muffler?
    #21
  2. larryboy

    larryboy Chopper Rider

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    Maybe 4 decibals louder than through the muffler.

    I'll shoot a video for you later today and post it here.


    Here you go:


    <iframe width="560" height="315" src="http://www.youtube.com/embed/cXJ-GBPnRho" frameborder="0" allowfullscreen></iframe>
    #22
  3. kellymac530

    kellymac530 motorcycle addict

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    Wow that is really good. Thanks for that.
    As Arte Johnson would say....Veeerrrryyy Interestink
    #23
  4. larryboy

    larryboy Chopper Rider

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    Very common mod, I'm not THAT into BMW's...I think it was only a couple of years of the GS that you could toss the muffler and it was still quiet. I'm sure somebody else knows more than me about that, but my 2001 is one of them.
    #24
  5. kellymac530

    kellymac530 motorcycle addict

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    I am trying to salvage as many parts off of my R1100RT and recoup some of my custom parts cost by selling them. The muffler and cat are one thing I think I can sell for more than I paid for the Ducati ones I bought, but If the Ducs don't get me where I want on volume, performance and sound then I will use the Rt and cut off the muffler and make a custom end for it.

    Great heads up on this option though, thanks.
    #25
  6. Andyvh1959

    Andyvh1959 Cheesehead Klompen

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    Da frozen tundra eh? 1.5 mile west of Lambeau
    On my 94 R1100RS the inner outlet tube cracked at the back of the muffler can, looked for crap, but sounded ok, kind of.

    So I cut the whole can off at the weld seam to the CAT converter. Made my own baffle design out of stainless sheet and tubing. The exhaust flow has to make at least one 180 turn to get out of the larger outlet tube. No packing or material inside the original can. Definitely not a straight through design, but definitely less back pressure.

    I tack welded the baffle setup, then hired a pro to TIG weld it all up and weld on the original can. Looks stock, wieghs five pounds less, adds a bit more sound (no one has even commented/complained it is noisy) and its durable. Got at least 35,000 miles on it since I did the design.

    I know it is freer flowing, because the bike would POP a lot more on closed throttle decel. So I installed a Techlusion to alter the fuel/air mix just enough to dial out the popping.
    #26
  7. Andyvh1959

    Andyvh1959 Cheesehead Klompen

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    Da frozen tundra eh? 1.5 mile west of Lambeau
    Follow up to my earlier post: I now also own a 2007 BMW R1200RT that I am converting into my interpretation of a R1200RS (using a Honda CBX fairing). I bought a Remus carbon fibre straight through muffler (used) from a BMW rider and mounted it on the R1200RT. With no insert (restrictor, noise reducer) installed I wondered how loud it might be. I have a noise meter app on my Samsung smart phone (handy free download), so I compared the output of the Remus on the R1200RT versus my modified/stock muffler on my 94 R1100RS. The two were surprisingly similar:

    At idle, standing next to the running bike (either one) in my garage, the noise meter held at waist level, facing rearward, alongside the bike, registered about 74 to 76 dB. With the throttle held at 4K, the meter registered about 94 to 96 dB. No one I ride with has ever commented that my 94 BMW with the modified muffler was loud or obnoxious. And the sound/tone of the 07 BMW was actually deeper and more resonant, even though the actual dB output was nearly the same. So I'm looking forward to the deeper tone of the 07 BMW with the Remus muffler, without being too loud or obnoxious for those 500 mile days.
    #27