Canister style expansion chamber

Fabian,

Have the perfect muffler for you to keep the police at bay:
muffler.JPG

Chris
AKA: BigBlue
 
actually, what would be interesting is to be given the peak rpm of this torque pipe, along with relevant dimensions without having to modify the exhaust port, and ill run a simple demonstration by designing and comparing equivalent pipes using my expensive software results, my cheap software results, my freebie "superstitious caveman" software results, and jaguars excel torque pipe results, on a stock standard motor :)

then may the answer be physically demonstrated, and the argument forever closed.

im also keen to try any other design thrown at me :)

this youngblood pipe. i tried to find a cutaway pic of it. good boy :) i can now sit here and analyse it a bit... im not so inclined to just throw the idea away, ive seen plenty of aircraft exhausts. that isnt quite normal.

strangely, it stems from the feeling that the rounded end is a parabola, with its focus point approximately at the end of the internal tube... on the short fat one, at least. the other one just looks standard really.

curtis youngblood has what many of us possibly dream of...unlimited funds. factory sponsoring. fancy gizmos to test everything with, every idea. and marketing geniuses if the product doesnt work too well in the end! :giggle:

firstly, i reckon make a model and put it in a ripple tank. watch wave propagation.

ill make you one, scaled up. what will you pay?

ill still say its not a true tuned pipe, but im sure it has something over a standard muffler/chamber...

note. an expansion chamber is just a chamber of any dimension. a tuned pipe is TUNED.


:toetap05: totally hi-jacked :toetap05:
 
ill make you one, scaled up. what will you pay?

I am sure we can come to some sort of agreement for the :beta1: version :)

The stacked pipe arrangement will have to (in my application) exit on the left hand side of the bike and be able to clear a 2" frame down-tube.
From what i can see the pipe would need to have the option of a secondary mounting tab to be able to tie it back to the frame just in case resonance proves to be excessive for the two exhaust studs.

I am sure that a well designed stacked pipe could offer significant improvement over the standard muffler yet give much more stealthy appearance than a conventional tuned pipe as well as reducing noise.

R/C helicopters typically operate in the 15,000 rpm band and due to the nature of helicopter operation they run constant rotor speed which required the engine to run at constant rpm, hence all of the performance pipes are designed to provide optimal power at a tuned rpm zone.
I can't imagine Curtis Youngblood designing his Muscle Pipe to make less power than his competitors products and i would imagine that a well designed stacked pipe concept (at very least) may provide some of the benefits of a tuned pipe with much better packaging.
 
HS, I wish you would make a torque pipe. Then you'd see its advantages over a normal pipe and maybe produce them for others. I was toying with the idea of having the local latino welder make them but getting these latinos to work is like pulling teeth.
 
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Jaguar, i completely agree with the notion of making a proper torque pipe, because it would be beneficial for those people who can get away with having such a pipe installed on their bike, and i wished that i was in an environment where i could have that kind of system installed on my bike.

Unfortunately many of us live in environments where the law persecutes people who ride a motorized bicycle, hence a more compact, less visually obvious pipe is beneficial to that sector of the motorized bicycle community.

Ideally it would be a great thing to have both: an optimally designed torque pipe (long version) and a compactly designed torque pipe for purchase.
 
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A standard pipe with a 5 or 6 inch header extension is the po-boys version of a torque pipe.
 
i use MH aerotools, freebie, has reasonable but not spectacular results. i looked on from there. strangely, it still uses the same basic calculations outlined by blair and bell, that are standard practise nowadays... it has bugs. mainly in the cone layouts it produces, rather than effectiveness. and being single stage, its rather limited in performance gains.

2 stroke wizard pro. i actually prefer its results to slightly costlier ones. shame i tried it last.

MOTA. meh. for value for money, wizard pro wins.

TSR. just freaking confusing and way too involved unless youre really into racing and i should have saved my money. oh well.

i had another one but it was on another puter and vanished. it wasnt worth reregistering.

and theres this one im yet to try! another freebie. http://microcarproject.tripod.com/html/expansion_chamber_design_softwar.htm


ill make a torque pipe if you calculate me the dimensions for a 48cc with no modifications, for a comprehensive evaluation.

just give me the rpm it will produce peak power, and ill design the same :)


but, for some reason, even when using freebie software, im getting results that tell me there no point going for more CC or changing anything else? they maynt be at the ballpark, but they must have live feed coming over cable or summink.

the reason i invested in software was because i have been making pipes on karts and bikes for a few years now. i didnt start on a pushy.

i fiddle with pipes now, not in the search of more power, but in the search of a simple, cheaply produced design that works and suits 90% of bike frames. power is no issue.


our thread? our own thread?

hows about pipe bomb? power in a small tin :)
 
well, look at that...

i have had my thinking cap on.

i maded a drawing :)

cannisterpipe.jpg

hopefully its displayed correctly.

its not to any particular scale, its just a diagram, the measurements are a byproduct. surprisingly good though :) maybe just try it out as is!

so, im contemplating that the end of that first "header pipe" is best shaped as a parabola.

the end of the internal tube is placed at this focal point.

this way, the positive wave travelling down the header from port, is focussed to a point, and the subsequent positive reflected wave is confined to the internal tube. the negative wave reversing and sucking exhaust out from port.

positive wave then travels down this internal tube, encountering some divergence to keep the negative wave building.

now, experiments will prove me right or wrong... a parabolic end opposing the internal tube, which reflects wave back, but up the external tube. these encounter the end of the chamber, which i feel is best flat but possibly tapered. not parabolic. this larger chamber acting much like the belly.

the wave reflects, returns to the lower parobola, reflects and is once again confined to internal tube where it intensifies.

emerges from end of tube, reflected, travels back into header raising pressure.


THIS IS JUST THE WAY I PERCIEVE IT> I MAY BE COMPLETELY UTTERLY WRONG.

so.

refer back to diagram.

critical dimensions i hopefully listed :)

any others, please mention.


so.

i propose, firstly, a simple ripple tank test. i make a simple model from some styrene sheet in a plastic tub. experiment with angles and shapes for perfect wave transfers, if any :)

two dimensions gives a good idea of wave propagation inside a tube, albeit at reduced speed.

it does give a visual representation, and therefore an understanding of the internal action of this design.

one concern is the main header from engine enters at right angle. the ripple tank will prove/disprove this.

maybe it will need a real tight but smooth bend directy to the internal tube, obviating the external tube.

theres the possibility of an elliptical end being used, with the property of being able to focus the wave "over there"...

ie, the external "header" tube is ovalised, with the internal tube and internal header side by side.

an ellipse has two focii, so the wave can be focussed from one tube to the other. (im not too sure about this bit... theory only... seems to work in concert halls?)

so, figuring out the maths.....

yee gods, i havent even started thinking that far! prove the concept with a simple model before proceding!

i know some of the basics may apply. possible divergences in tubes, etc.

reflection points hence curves of parabolas, which govern certain diameters/lengths. i really do feel the focal points play a major role in effectiveness of this design, if any.

lengths. speed of sound, temperature and density/pressure.

stinger/bleed placement...

i do feel, that, if this pipe is doing what i picture its doing, it should actually do something!
 
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