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Re: Guide to: Exhaust Repacking [message #216746 is a reply to message #216745] Sat, 03 July 2010 01:32 Go to previous messageGo to next message
Kermit is currently offline  Kermit   United Kingdom
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Registered: June 2003
Location: Yorkshire
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(22) Giacomo Agostini
Yeah, Micron went belly up about 2-3 years ago...shame really cos their cans while not quite the full on biz like Akra, Remus, Arata, for UK made cans weren't half bad especially the shaped understeat ones for the 05 Blade and that serpent system which always seem to get good bhp figures Sad

Next time I pack a can, I might well try your way Onda just to see the difference smile

[Updated on: Sat, 03 July 2010 01:33]

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Re: Guide to: Exhaust Repacking [message #216803 is a reply to message #216746] Sat, 03 July 2010 23:05 Go to previous messageGo to next message
SPAL is currently offline  SPAL   United Kingdom
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(13) MotoGP Champion
Hi All,

This is obviously a very technical subjet,

I am unsure of something, which you guys may or may not be able to answer.

Talking to a guy @ work about the whole exhaust repacking thing and he say : Don't wrap too tight, as it will be louder, you have to allow the gases through the holes into the packing.

Now, there is a high possibility (knowing him) that this is CRAP. but after reading ondablades post, it sounds like he rammed loads of loose packing into the silencer, an kermit lightly wrapped a far denser packing.

Now what actually quitens down a pipe? and how does a removable baffle work.

SPal
Re: Guide to: Exhaust Repacking [message #216804 is a reply to message #216803] Sat, 03 July 2010 23:24 Go to previous messageGo to next message
Kermit is currently offline  Kermit   United Kingdom
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Registered: June 2003
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(22) Giacomo Agostini
Your matea idea sounds feasible as I can't understand the concept although not sure on the physics of it. Personally I wanted to make sure mine was well padded and no gasses get to the outer sleave as CF would soon be weakened by hot gas but I guess there's maybe a compromise.

As for my baffle, you can see it in this pic still screwed into the end cap

http://i498.photobucket.com/albums/rr345/KermitX/CBR929/CBR929_Exhaust_7.jpg

It doesn't do a brilliant job and only seems to knock maybe 2db of the loudness but the circular disc part near the end fits fairly snugly into the inner cores which will while letting approx 50% of the gases straight though its narrower tube, forces a fair amount of the other gases to rebound about a bit and find their way out other routes such as the packing - thats my take on the concept anyway
Re: Guide to: Exhaust Repacking [message #216806 is a reply to message #216803] Sat, 03 July 2010 23:30 Go to previous messageGo to next message
ondablade   Ireland
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(15) Kenny Roberts
I can only say from my own experience Spal.

No doubt there is some limit where it becomes too tight, but equally the 'wrap' type packs i've seen are so loose that it's inconceivable that they do a decent job. If nothing else tighter packing should stop the tube and shell from resonating in any way.

The loose wrap certainly didn't do a great job in a Micron can i had, but maybe there were other factors too. On the other hand packed tightly and it got a lot quieter, and stayed that way.

The Hindle system i had worked really well, and was very quiet. I never re-packed that, and it never really got any louder. It felt very much when handled that it was tightly packed too - it had such a light shell that it almost relied on the packing tos top it dinging....
Re: Guide to: Exhaust Repacking [message #216808 is a reply to message #216806] Sun, 04 July 2010 02:48 Go to previous message
SPAL is currently offline  SPAL   United Kingdom
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(13) MotoGP Champion
It strikes me the only way we will answer this question is to undertake a controlled experiment.

take 1 exhaust,

take out all sound deadening stuiff and measure db.

pack with either loose fibre glass or wrap. measure again

remove what weve done and do other type . measure again.

answer - which isd best

BUt, i hear you say, is there a better alternative .... F88k knows. Laugh #

Spal
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