mad_skillz
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| posted on 13/2/03 at 09:18 PM |
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motorbike exhausts
I am using a 2.0 dohc engine for my locost and am thinking about putting motorbike silencers on it. Has any one done this, and if they have how? Is it
better to use two silencers as the engine displacement is larger than a bike or is it ok to use one etc?
Alex
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Liam
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| posted on 13/2/03 at 10:20 PM |
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I'm thinking of using bike silencers on mine. Pretty cheap for even a nice titanium one of a ZX9 cos all the bikers want to replace them with carbon
ones.
I would have thought if one is good enough for a monster bike engine it will be fine for a relatively sedate 2.0 dohc. Noise isn't proportional to
CCs is it? Never really thought of it that way. I'm using two anyway - V6.
Liam
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Metal Hippy™
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| posted on 13/2/03 at 10:41 PM |
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What kind of price we talking per can?
President of the Non-conformist Locost Builders Club. E-mail for details...
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stephen_gusterson
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| posted on 13/2/03 at 10:56 PM |
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it depends on the construction of the exhaust.
exhausts are not just an obstruction that magically 'muffles' noise.
the type that have baffles are designed to reflect sound back on itself, to give a self cancelling effect.
the 'straight thro' type has glass fibre wadding around a perforated tube that absorbs sound reflected into the wadding.
I STRONGLY suspect there is a relationship between at least CC or exhaust velocity at least.
Onmy granada donor, the car had two front boxes (two exhausts) merging into a further combined flat box, then exiting as two pipes that merged into a
single back box (strait thro type). The were FOUR boxes in this system.
I now have two 'straight thro' back boxes in my car, (one for each side of the v6) and the noise, even in a garage, seems suprisingly low. However,
each exhaust silencer is 'seeing' only 50% of the exhaust volume, and hence 50% velocity, so the length of pipe with wadding around it in the box
has twice the chance of dampening the sound.
http://www.howstuffworks.com/muffler.htm
the link explains pretty well - look at the bit on 'glass packs'
atb
steve
[Edited on 13/2/03 by stephen_gusterson]
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Liam
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| posted on 13/2/03 at 11:04 PM |
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Hipp-o
I think my buddy paid around 50 squid for a standard ZX9R can. It even says titanium on it, man! Cheaper than new cherry-bombs and stuff if you can
find em, and very sexy looking too.
Liam
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Metal Hippy™
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| posted on 13/2/03 at 11:14 PM |
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Not bad.
I think I'd use twin pipes from my straight six. The manifold is two separate parts bolted together with an output each....
President of the Non-conformist Locost Builders Club. E-mail for details...
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