Wave dynamics type question.

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Tioli
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Wave dynamics type question.

Post by Tioli »

Hi I have a bit of a wave dynamics type question. I thought I would run it past their as you seem a learned bunch.

My problem is I have made a sound wrap for my exhaust. Now this worked just fine once I figured out how to manage it. Well it did work fine till I pushed the bike further and it just gave up and wanted to fall off. (Page 30 from my signature link for the details)

Part of this pushing the bike further was gearing it up to a point where I no longer could get instant wheel spin sub power valves opening. Top end is still more than enough and behaves like a four stroke by having long legs.

Putting the sound wrap on changed the expansion chamber by keeping the heat in which turned my desert pipe into a topend road race pipe (the waves mover faster in a high heat environment) I moved the revs back down enough with a 20mm spacer.

With the taller gearing I feel I can get sharpen the bottom end up by removing the sound wrap. This should match the bottom end with the top end again and we start again.

Now if I remove the wrap I have a opportunity to remove sections. My thinking is waves travel by reflecting and spherical radiation which is controlled in the pipe. Turns cause a loss in the sharpness of the wave front which should be kept to a minimum. In a perfect world we would all have straight pipes but we can't. Now if I kept the sound material on the slow side of a bend I may be able to trick the pipe into thinking it's straight.

Now don't give me the maths as I don't know it just the pictures. I have ran this through my head and can see it behaving in a few different ways that contradict each other. Add to that the wave has to come back the same way.

Is the inside or outside the slow side of the bend?
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
jjavaman
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Re: Wave dynamics type question.

Post by jjavaman »

http://www.dragonfly75.com/motorbike/ECtheory.html
Just what are you trying to achieve? Common sense says the inside is the faster(shorter) side.
97-220 with a PC pipe. 2015- RB carb and head mod
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Jaguar
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Re: Wave dynamics type question.

Post by Jaguar »

sound absorption material on the inside or the outside of a curved portion of pipe will not affect what's going on inside of the pipe at all as far as the wave action goes
Last edited by Jaguar on 06:55 pm Apr 11 2016, edited 1 time in total.
Performance CDI -- KDX motocross mods -- the SR KDX -- expansion chamber analysis---> http://www.dragonfly75.com/moto/
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Tioli
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Country: Tasmania AUS

Wave dynamics type question.

Post by Tioli »

Thanks guys it's making me think harder. What I'm working on is a little side theory that I have never seen done yet. Mostly I think because it was not possible and now it is.

I have tried to explain it better with pictures at the bottom of page 30
https://trials.com.au/forum/viewtopic.p ... &start=580

It's early days so please point out where I'm wrong.

Just had a thought localised heat may do nothing :hmm:
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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