Baffle Wrap

Discussion in 'Technical Help' started by dirty big hands, Apr 27, 2022.

  1. dirty big hands

    dirty big hands Active Member

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    Along with my Thunderbird sport I also have a gsxr track bike.
    It needs quietening down a couple of db's!

    There is a removable baffle in the can, but with no wrap around it, just a perforated metal tube.

    Is it as simple as wrapping a bit of baffle wrap around this, to reduce the noise?
     
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  2. Linx

    Linx Well-Known Member

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    The space between the tube and the can should be stuffed with silencer wadding. It will make it quieter.
     
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  3. Eldon

    Eldon Elite Member

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    In a word yes @dirty big hands

    longer response.... A mate recently purchased a new can for his 675 str.
    Straight through with an exit diameter of about 80mm was just ridiculous in noise levels. We made a baffle up and that knocked the edge off but not enough.
    I had some spare new offcuts of "cotton wool" baffle sheet used for my last 2 stroke silencer repacking job.
    He wrapped the new baffle with the wadding and I'd advised him to wrap stainless locking wire around the wadding for ease of placing and removing the baffle which he did.
    You certainly wouldn't class it as too quiet now but it solved the issue and made it acceptable in my opinion for road use.

    Note. When he hit the rev limiter in about 3rd the other day in front of me I could clearly hear it above my str with twin Arrow cans on :p
     
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    Last edited: Apr 27, 2022
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  4. PatW

    PatW Senior Member

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    You hum it, I'll play it..
     
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  5. dirty big hands

    dirty big hands Active Member

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    Oooo, whatcha gonna play it on?
     
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  6. dirty big hands

    dirty big hands Active Member

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    Cool, thank you, I'll get some.and give it try!
     
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  7. Eldon

    Eldon Elite Member

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  8. Eldon

    Eldon Elite Member

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    Double post ... page was stuck :rolleyes:
     
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  9. dirty big hands

    dirty big hands Active Member

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    So..... I wrapped the baffle.
    And using a db meter on my phone before and after, it's taken just over 3db off.
     
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  10. Eldon

    Eldon Elite Member

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    3db is quite a lot if those numbers are reliable

    10db if I remember correctly is twice the volume (energy) its a strange logarithmic scale which takes some understanding to reality values ;)
     
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  11. Helmut Visor

    Helmut Visor Only dead fish go with the flow
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    An increase of 3db is doubling of intensity so a decrease of 3db is a halving of intensity ;)
     
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  12. Eldon

    Eldon Elite Member

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    Thanks, I knew it was something like that, either way 3db is a worthwhile gain I'd say.
     
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  13. dirty big hands

    dirty big hands Active Member

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    It might not be the true decibels, but hopefully the 3db drop is accurate.

    Isn't it something like 11db is twice as load as 10db, not 20db (10 doubled)???

    Either way, the bike tested at 101db (just) last track day, but the people who have bought new houses next to 100 year old airfields complain about noise.... so the sound level is getting stricter, hence the need to quieten it down a bit.
     
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