Inside a 950 ADV muffler, the ultimate cutaway view...

Discussion in 'Crazy-Awesome almost Dakar racers (950/990cc)' started by ganshert, Sep 7, 2007.

  1. ganshert

    ganshert not sleeping

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    I tagged along with Ned to Wayne's house to do some surgery on 950 ADV mufflers.

    The goals;
    1. De-Cat a couple sets of ADV / SM cans.
    2. Make a luggage rack for the SE.
    3. Figure out how to mate a set of ADV de-catted cans to my old VFR

    I'm talking with Wayne about #3 and this is how the conversation went...

    Me; I need to fab up a mid pipe to mount 950 cans on my VFR
    Wayne; what year VFR?
    Me; '87
    Wayne; no way
    Me; yes way
    Wayne; do you want a stock set?
    Me; uh, yeah
    Wayne; I have a BRAND NEW set off of an '86
    Me; NO WAY
    Wayne; YES WAY
    Me; Woo Hoo

    Wayne had been hanging on to this set for years becasue he knew somebody would need them someday. Thanks for being a pack rat Wayne. I owe you big time, I'll come up with something :deal

    this is Wayne, he has mad fab skills
    [​IMG]

    this is Ned, Wayne, and the new guy (whose name I can't remember), he came by to see the stich Wayne has for sale on this thread

    Ned; "So we are modding a 92 Goldwing trike for this years Baja 1000"
    New guy; "hmm really" while thinking, you're weird
    Wayne; "uh, he said Goldwing, cool!"

    [​IMG]

    exhibit A; stock 950 ADV muffler
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    The plan was to sacrifice this one for the greater good. We know you all want to see what's inside right????

    uh, how do you turn this on?
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    Wayne demonstrating proper technique
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    half way there
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    pulling out the little bit of packing? / heat sheild? material that got caught on the sharp edges when it was removed. It was a big sheet of fiberglass or some similar type of cloth wrapped twice around the metal mesh inner layer
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    cutting out the inner layer of mesh (outer skin, heat sheild material, inner mesh)
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    almost there!
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    Wayne said; "looks like a bong"
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    Ned said; "note the flow pattern"
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    so we concluded that the best way to de-cat it was to cut off the mounting flange, remove the cat completely, and weld the flange back on...
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    mmm, tasty cat
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    "I weld good"
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    so how much does a cat weigh???
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    It was so light that Ned thought he needed to hold it on the scale so it didn't float away. After he let go of it... 1lb.
    [​IMG]

    Hope the internal view helps somebody.

    Couple of points to remember;

    the cat weighs 1lb

    If your going to drill / hammer it out without cutting the end off the can you stand the chance of the pieces falling down into the muffler and you will have a hard time getting them out

    If you cut the can open the best place to do it is just behind the flange on the tapered part so that you get the entire cat out instead of just the end of it. This is debatable but what we thought after we cut the first one open.

    Any questions, what did we miss????

    As for goal #2...

    Ned and I played around with Wayne's sweet tubing bender and bent up some 5/8ths cromoly for a rack to keep Ned's soft bags off the exhaust and out of the rear wheel.

    [​IMG]
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    the bender was awesome, it made it super easy to make two mirror image supports for the soft bags

    Neds gonna weld them up and post a pic for us.
    #1
  2. 1stiski

    1stiski Ride that nasty thing

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    that explains why those stock cans get so HOT !!
    #2
  3. neduro

    neduro Addict Super Moderator

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    good report, Ganshert!

    Anyone have a flow bench? We're interested in knowing what a cat flows vs. something that size unrestricted.
    #3
  4. Mukluk25

    Mukluk25 Hitchhiking to Bingo

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    Sweet report. Selling GS to get pipe bender..........and SE:)
    #4
  5. yellowbronco

    yellowbronco Been here awhile

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    Beautiful! Let us know what the de-catted cans sound like. I've got a set of FMF Ti factory 4.1's on order (since June!!!!!:kboom ) and am thinking about alternatives to hold me over until they finally get them in production. Maybe they're waiting for enough orders...hint, hint.
    Tom
    #5
  6. Ooobah-Moto

    Ooobah-Moto Banned

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    You unlocked the holy grail!!!!....... or is it Pandora's box [pipe]?!?!

    To Akra or not, that is the question!

    After seeing your report I can see why de-cating the pipes doesn't make them any louder. The baffles keep the sound in check. To cure the excessive heat, removing the cat's is going to be an obvious solution... but to uncork that sweet v-twin sound?!?!?!?
    #6
  7. neduro

    neduro Addict Super Moderator

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    To me, the issue is that the cans weigh ~11 lbs each (22 lbs total!), ~10 w/o the cat. I think good aftermarket options are more like 2 lbs.

    :dunno
    #7
  8. Hayduke

    Hayduke ///SAFETY THIRD/// Super Moderator

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    The hard parts catalog claims the Akro's are 59% lighter than stock. :dunno
    #8
  9. MSH

    MSH The Salt

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    HOLY CRAP!!! You guys are awesome!!! How much did the sound change?
    #9
  10. Ooobah-Moto

    Ooobah-Moto Banned

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    Now that I see where the cat's and where the baffles are, I'm beginning to think that the heat is not only b/c of the cat's. The shear amount of piping/tubing and metal found in the middle of the muffler absorbs the heat... like a heat sink of sorts.

    Cutting off the mounting flange and welding it on a set of straight through pipes of your choosing seems like good solution for those (including me) who think it's preposterous to pay $1000 for a pipe of titanium! That is, if your objective is to cut the heat and gain some grunt - and not spend $$$$ doing it!!! Besides, you'll be the only kid in town slingin a Yoshi pipe on your 9fiddy!!!
    #10
  11. crazybrit

    crazybrit Long timer

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    Wasn't this a prop for some StarTrek movie .... the one where they go back in time to get the drunk guy to make the first warp drive flight ever.

    In fact Wayne looks a bit familiar .......
    #11
  12. GPZ1170

    GPZ1170 Consumer Whore

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    Nice job. I'm glad my old pipes were used well.
    #12
  13. ganshert

    ganshert not sleeping

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    yup!

    we were allowed more leeway in the destruction of the 950 cans since Wayne happened to have a stock set of mufflers for my VFR
    #13
  14. c munch

    c munch Destination unknown

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    I removed the cats from mine , no real change in the sound but a slight rattle in one of the cans from I would guess a piece of tin from the casing of the cat falling into the can . no real temp change either . was it worth all that work , hell no . Now I have a set of wings on the beast , much better.
    #14
  15. Zecatfish

    Zecatfish XTique Rider

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    Stupid question maybe, but why could you not just go with a pair of glass packed two stroke silencers? IT would be a little loud.. maybe.. but dunno just a thought.
    #15
  16. DakarNick

    DakarNick Swabee

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    Wayne, what bender is that? What size OD tube can it bend? :ear

    Nick
    #16
  17. beyondhelp

    beyondhelp likes cheese too.

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    #17
  18. Wayne Weber

    Wayne Weber why are we stopping?

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    It's from Pro Tools, it's around $500 plus about $150 per die set, and it can bend about anything. They have dies for tube, pipe, square tube. It's one of my favorite tools. I have dies for 5/8" thru 1 1/4" and it's awesome. no effort and verrrry controlable. I can't say enough.

    Here's a link, (EDIT make sure you get the $59 magnetic angle measurer! and then get a magnifying glass to see it, but it's also worth it!)

    http://www.pro-tools.com/200.htm

    It's really cool.
    #18
  19. randel

    randel Been here awhile

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    Maybe solution for heat problems may be this:
    Cut muffler open from rear end (red line) and remove last pipe so gases can flow through directly (green line) and not been directed back through middle section (blue line).

    Can't see from photos is that last pipe welded together with other pipes in the middle section or will it slip out to rear when cut open as shown.
    I saw similar mod done with BMW 1150GS mufler with good results.
    #19
  20. Ooobah-Moto

    Ooobah-Moto Banned

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    If you were to cut the muffler open on both ends; having removed the cat on the one end.... Regarding the other end, where the exhaust comes out.. does anyone think inserting a pipe (or anything of substantial width and length) and use it to beat/pummel out the remainder of the internals would work? You would be left with a gutted/hollow can. Although, there wouldn't be anything to create back pressure..... doesn't the 950/990 need some back pressure?????

    Then again, if you welded a perforated pipe (hardware/farm supply store) to one of the end caps (cutting it to the same length of the stock exhaust can) and filling the void with glass packing... you would have a legitimate straight-through exhaust pipe.
    #20