Muffling

VPulse · Derestricted Danger Joined: 22 Oct 2004 Karma :

Hey, I was wondering if anyone knew a reasonably simple technique to reduce sound from the engine. 80cc engine.

Possibly some sound obsorbing material at the end of exaust, anything.

mchaggis · World Chat Champion Joined: 10 May 2004 Karma :

What's wrong with the muffler it has just now?

Generally on a two-stroke they'd use a type of wire wool packed in varying size chambers along the length of the perforated inner pipe to absorb the high frequency noise in the fibre and the low frequencies in the gas spring effects of the chambers.
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VPulse · Derestricted Danger Joined: 22 Oct 2004 Karma :

Muffler works quite well, haven't tried it without it, but I was thinking more along the lines of further sound reduction if possible.

Ste · Not Work Safe Joined: 01 Sep 2002 Karma :

Well any further restrictions on the exhaust will make the bike less powerful and run worse. Has it got an after market race system fitted? I would say you're best bet is to get a system which is road legal as standard, lots less hassle and will work out cheaper or about the same.

VPulse · Derestricted Danger Joined: 22 Oct 2004 Karma :

I do not beleive I have w/e that system is on. I was thinking something basic such as some sound obsorbing material a bit after the exaust end, or on it. It's not any high priority but it would be intresting to have a nearly silent system.

Ste · Not Work Safe Joined: 01 Sep 2002 Karma :

With a two stroke you change the way the exhaust works, which adding in extra baffling will do, you'll have to set up the fueling so its working as well as it can. It will sufocate it even more and would expect it to run like a heap of shit so if you are wanting to try modifying and breaking an exhaust I'd find one from a breakers going cheaply and use that as you won't be as bothered about having to chuck it in the bin.

cagiva gezzer · World Chat Champion Joined: 17 Mar 2003 Karma :

Put an extra length of pipe on the end and put a 90degree bend in to it so the sound pulse is forced towards the ground. Or, a 180 degree bend so the pulse is directed back under the seat.
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stevo as b4 · World Chat Champion Joined: 17 Jul 2003 Karma :

If its an expansion chamber type system, then lagging the expansion part of the pipe will help reduce the tinny sound from a 2 stroke, as manufactuers std chambers usually use this meathod with a layer of sound deadening material between two layers of metal, reducing noise and adding weight. The silencer does reduce the overall noise level, but as long as you use a straight through absorbstion type silencer it shouldnt matter what length or size it is, just make sure that the tailpipe diameter is not less than the std silencer.

TheShaggyDA · Repost Police Joined: 14 Jun 2004 Karma :

One has to wonder at why you want a silent bike.
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hustler · Crazy Courier Joined: 29 Jul 2004 Karma :

VPulse · Derestricted Danger Joined: 22 Oct 2004 Karma :

Thanks for the replies, il try out the suggestions sometime soon.