How to quieten a expansion chamber

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Tioli
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How to quieten a expansion chamber

Post by Tioli »

I love the sound of a twostroke but my ears don't anymore. This is how I quietened my aftermarket pipe to the same level as a OEM double walled one.
It took a few goes before I figured out how to apply it and now I'm happy enough to say if you have the need it can be done.

It starts half way down page 20 and evolves to page 23 (sorry about the stuf in between)

Link to page 20
http://www.trials.com.au/forum/viewtopi ... &start=380
Trials.com.au, forum, all about me, my long time friend the prancing horse

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Tioli
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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Jaguar
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Re: How to quieten a expansion chamber

Post by Jaguar »

When I first put a new ProCircuit pipe on it sounded like someone was banging together pots and pans, but then that slowly died away as the inside of the pipe got its normal layer of soot.
I raced thru your pages but didn't catch what the two materials were that you put on the pipe.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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Tedh98
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Re: How to quieten a expansion chamber

Post by Tedh98 »

Great job on trying something new.

But I have to ask- if you were wanting to quiet things down for your own ears, why not just use earplugs? About a 1/3 of the guys I ride with use them.
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Tioli
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How to quieten a expansion chamber

Post by Tioli »

The material is called Megasober D10. And a home made carbon fibre Kevlar weave guarde. How I made that is some pages earlier.

My ears ring all the time so am very conscious of preserving what I have. I use moulded ear plugs but MX helmets are more open at the bottom and sound is more bone conducted.
This is not a path I wanted to go down its nesesity dictated the need.

Your clutch is on the list Tedh98 and your ignition is not un-noted Jaguar.
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
Deseret Rider
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How to quieten a expansion chamber

Post by Deseret Rider »

After all was said and done----is the bike radically quieter now? ( I went riding yesterday with my son whose 200 with stock exhaust is much ---way more---quieter than my 220 with aftermarket expansion chamber and FMF muffler. So I am wondering if a similar project on my 220 would make it as quiet as my son's 200? What do you all think?
The Duck of Deseret (Deseret was Utah's first name)
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6 Riders
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Re: How to quieten a expansion chamber

Post by 6 Riders »

Use a stock silencer for quiet, they are much quieter that the fmf units, but heavier, performance doesn't suffer either.
newbbewb wrote:^what he said.
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*side note...I'm drunk, so try to read what I'm trying to say, instead of what I actually type
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Tioli
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How to quieten a expansion chamber

Post by Tioli »

I run a straight through silencer with the tip pointing to the ground about a meter behind me. That works ok as a silencer. The chamber sounds similar to my mates OEM doubled walled RMZ250. The ting ting ting is gone.

The lining will hold the heat in similar to a OEM pipe. For 220 it will mover the tuned length towards topend. How far is difficult to predict and may not be a bad thing. One of those .5 mm torque rings may be all you need to compensate. I went a bit more than .5 but that was because I wanted to as I have a desert pipe on a 200 with more than enough topend.

So far mine is the only one like it and my motor is not standard so it's all experimental.
2001 KX125 with a 1997 KDX Tioli Hp motor

My KDX journey starts at the bottom of this page:
http://www.trials.com.au/forum/viewtopi ... &start=160

Trials.com.au / Forum / All about...me! / My long time friend the prancing horse / page 9
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fuzzy
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Re: How to quieten a expansion chamber

Post by fuzzy »

The stock pipe is a tractor....I love them.
'91 KDX 200 Project $300 KDX
'95 KDX 200 Project $600 KDX
'94 WR 250 Always a project
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Chuck78
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Re: How to quieten a expansion chamber

Post by Chuck78 »

Tioli wrote: 04:31 am Jul 04 2015 Link to page 20
http://www.trials.com.au/forum/viewtopi ... &start=380
Trials.com.au, forum, all about me, my long time friend the prancing horse

Thanks
Tioli
Wow... Tioli, your hybrid build documentation and engine building attention to detail and small but significant mods everywhere is incredible and enlightening! I will have to give this a good heavy winter read here next month and take notes, before I split the cases on my '99 220 to build it up fresh...
'97 KDX220R - purple/green! - KLX forks, Lectron, FMF, Tubliss
'99 KDX220R project - '98/'01 RM125 suspension, Titanium hardware, Lectron Billetron Pro, Tubliss
'77 Suzuki PE250 & '83 Suzuki PE175 Full Floater - restomod projects
'77 Suzuki GS750-844cc, '77 GS400/489cc & '77 GS550/740cc projects
'62 GMC 1000 Panel Truck
'88 Suzuki Samurai TDI/Toyota swaps
'88 Toyota 4x4 pickup
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