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Old 07-09-2011, 08:34 AM   #16
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Originally Posted by DJ_Shakespear View Post
Exactly, you're not wrong there.

But here is what I know - dont take it word for word, I might have confused something with another thing, but its what Ive learnt before.

A tuned pipe is more or less specifically designed to create peak power at a particular RPM in its design, but that would be pointless if it worked like that - crap power everywhere else, and then BAM!! Power!!) So in its design (im not EXACTLY sure how hey make tuned pipes) the manufacturers design them so that they behave the way they do today - heaps of power up top, or on the bottom end, or for more efficiency, whatever.
The way it acts as a supercharger is that the pulse from the cylinder )sound wave) travels down the manifold and through the tuned pipe, and after it reaches the expansion chamber (i think its called) and reaches the part where the diameter gets smaller, this sound wave gets sent back to the combustion chamber to create this 'plugging' effect, and whatever is already being sent into the chamber is forced in via its momentum and there is what is basically its own supercharging effect. The shorter the path, the better the higher RPM will be, and vice versa.

Obviously it would be terrible to make one specifically for a certain range and leave the rest horrible, so they counter for that and make it all good i guess. Hard process, but they know what they are doing

By introducing a supercharger, this plugging effect could possibly be entirely destroyed as its negating that plugging effect, and just sending more air/fuel through than needed. Im not saying it WILL NOT work, just that it would be way better in a 4-stroke situation where the exhaust is closed during the intake stroke.

Phieeewwwww...
Coming from the 1:1 scale forced induction world you are wrong. A tuned pipe is providing backpressure (I think this is where you were headed with the comment). Backpressure is the bane of any FI, you want to get as much fuel and air in and out as quickly as possible. The more material you can cram in the more power you can make (assuming you have suffecent power to light it off)

A tuned pipe is like a tuned exhaust on a 1:1 car, if you can create the right blend of pressure and flow you can increase both HP and ft/lbs across the entire range. Too little restriction and you actually will looks power across the power band due to not enough backpressure. This is part of the reason you see FI vehicles (think diesel pickups especially) with large exhausts and that most naturally aspirated cars and trucks top out at around the 2-3in diameter mark.

Again I think you got a little confused when you were talking about power "hitting" and thinking of peak. This happens with larger turbos as you get the needed exhaust flow. The reason turbos are so efficient is due to them using the waste heat (exhaust) of the 4 stroke cycle along with the waste air (exhaust).
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Old 07-09-2011, 09:13 AM   #17
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well yeah for those that know, then I would be wrong, but I guess the main point I was trying to say is what you said with 2-strokes having piston porting as a means of using them as valves - its doesn't work all too well. I just tried to make it (my other post) as small as possible without going into so much detail. With back pressure, it IS almost the same principle in 1:1 engines You want to have biggest and smoothest, but if you go too big then you lose that power.

I think we might have gone a little off-topic

Back to the original subject, the supercharger may work, but how well it increases total power is hard to tell. I guess theoretically it shouldn't work, but as we have read/seen, it does work!
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Old 07-09-2011, 09:15 AM   #18
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Exhaust and intake systems for two strokes are a completely different theory from 1:1 four stroke. It's hard to explain in a short post (and I'm not exactly an expert on it myself) but you can NOT use traditional 4 stroke exhaust theory to explain what goes on in a proper 2 stroke tuned exhaust. For more info, read up on Gordan Jennings.

http://edj.net/2stroke/jennings/
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Old 07-09-2011, 09:19 AM   #19
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Originally Posted by wingracer View Post
Exhaust and intake systems for two strokes are a completely different theory from 1:1 four stroke. It's hard to explain in a short post (and I'm not exactly an expert on it myself) but you can NOT use traditional 4 stroke exhaust theory to explain what goes on in a proper 2 stroke tuned exhaust. For more info, read up on Gordan Jennings.

http://edj.net/2stroke/jennings/
+1
Lets just wait and see a vid of it running, would be interesting to see
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