Baffle Fiber

Discussion in 'Engine, Fuel and Exhaust' started by Drumrguy, Oct 30, 2009.

  1. Drumrguy

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    Ok, Quick rundown, I got decell pop with my 05 Ultra Classic, I repacked the baffles and it seems to have gone away alot, someone please explain. Been on 2 dynos, did not have problem before initial dyno tuning, the packing for the baffles was almost gone from the dyno, does this make any sense. I am not running lean, like I said 2 different Harley dealers have dyno tuned my bike, I know the tuning is right, just wondering if the baffle Fiber being almost gone could cause this. Thanks for the help in advance.
     
  2. Hoople

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    What does "the packing for the baffles was almost gone FROM the dyno"

    also, did you Ever have NO decel pop while running unpacked baffles
     
  3. glens

    glens Banned

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    I doubt the exhaust gas is flowing through (as in being "filtered" by) the packing, so the change wouldn't be that great. Yeah, there might be a miniscule difference, but I'd say the audible sound quality of the mufflers is what's mostly changed. That is, if they don't sound vastly different I doubt they're flowing so. Shouldn't be the cause of any new popping; I don't think the packing would absorb enough to cover up such sound and I don't think the muffler's allowing any more or less fresh air back up the tube.
     
  4. NEWHD74FAN

    NEWHD74FAN Experienced Member Retired Moderators

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    I think we need clarification what "packing" you are talking about. Heat resistant fiberglass packing is sometimes used to "supplement" the metal baffles to quiet the exhaust a bit. But as many have found out, running Wide Full Open throttle will "blow out the fiberglass packing" and then as Smitty says, the bike will sound different with leaner mixture because less backpressure exists.
     
  5. Bud White

    Bud White Well-Known Member Retired Moderators

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    if the fiberglass wrapping or packing like my bassanis use blows out you will get a different flow and sound and yes it will lean it out .. also you will usually get some popping and they wont run as well. as the 2 strokers they will tell you when the baffles and packing go you know it .
     
  6. Drumrguy

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    Ok, here is clarification. When I got the bike, had no problems. After bike went back and got tuned on the dyno, I started to get decell popping. Went back and forth with the dealer several times, no better, took it to another shop and it got a little better and the HP increased a little, but still had some popping. The guy that ran the dyno at the second dealer, said he thought it was the mufflers, so that led me to pulling out the baffles, which made me think I did not have this problem until the dyno came into play = heat on the mufflers which will eat up the fiber packing, especially for how much mine has been on the dyno lately. So, I went to the dealer and got new fiber packing, repacked the fiber, reinstalled, test rode, and what do you know, it got better. So, I am thinking that the packing in the baffles obviously helps my bike out, if this makes any sense? Stupid bike!!!
     
  7. Bud White

    Bud White Well-Known Member Retired Moderators

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    yes it makes sense .. but the dyno wasnt the onyl reason the packing burnt out it just does over time anyways.. Dyno would just speed it up
     
  8. Drumrguy

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    I just do not understand why the dealer that built my motor did not point me in that direction, I would say all the heat from the dyno helped kill my packing, there was probably six inches left on my baffle, so far so good, but what a job he did with the bike, I can really feel those cams now. :bigsmiley24:

    Forgot to mention, this bike is killing me, I am remembering why I did not want another twin cam now. This bike is gonna be the death of me. I hate when things are not perfect. :no
     
    Last edited by a moderator: Oct 30, 2009
  9. glens

    glens Banned

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    Did you say they were Rush mufflers? Mine have backward-facing louvers stamped in a spiral around the straight-through core. The packing absorbs higher frequencies and the sound changed over twenty-some thousand miles but I can't say my tune was affected by it. Least-wise not that I noticed. And the sound never got bad.
     
  10. Drumrguy

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    Yes, they are Rush, I guess that the new fiber packing helped me out. Don't know why or even understand why but I will take it. But I have alot of motor work done to my bike, I think that all the dyno runs killed my fiber packing from the heat on the dyno.