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Post by zambia on Dec 31, 2011 15:58:58 GMT -5
If that's the practice chamber...how much do you want for it? ;D
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Post by Walms on Dec 31, 2011 17:21:54 GMT -5
If that's the practice chamber...how much do you want for it? ;D I believe Don's pkan is to keep the collector and swap the belly sections to change pipe designs. The header Assy. is aa short I could make them while keeping them equal length. Once he has this collector together he will be able to whip out different pipe designs pretty quick for experimenting... Pretty cool project! Don, you should think about a sliding belly section so you can change the pipes tune as it revs up.. ;D
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Post by tripletriplenut on Dec 31, 2011 17:49:19 GMT -5
get out of my head ;D
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Post by Walms on Dec 31, 2011 18:20:18 GMT -5
;D glad we're on the same page!
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Post by Curtis on Dec 31, 2011 18:46:54 GMT -5
if this works, sign me up for one for my s2 that you guys don't know about yet :-) :-)
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Post by tripletriplenut on Dec 31, 2011 20:53:36 GMT -5
if this works!! blasphemy. no pipes for you!
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Post by Curtis on Dec 31, 2011 23:12:28 GMT -5
if this works!! blasphemy. no pipes for you! :-) :-) I got all the faith in the world in ya don!
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Post by teazer on Jan 1, 2012 10:45:29 GMT -5
Very interesting project. I'll be very interested to see how the pipe turns out on the dyno.
How did you design the pipe to allow for the extra gas volume without messing up the sonics? It's hard enough to avoid waves going back at the wrong time into the wrong cylinders and when I sat down to re-design a 3 into 1 pipe I have on my GT750, I realized that the wave versus gas volume was another issue to work through.
I'm trying a "factor" derived from 4 stroke theory to see if that works. Care to share some insight?
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Post by tripletriplenut on Jan 1, 2012 11:18:27 GMT -5
so what problems are you having with spent exhaust gases? how is your design of the header screwing up the sound waves?
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Post by Curtis on Jan 1, 2012 11:44:30 GMT -5
question don, why are you welding the pipes together? will the vibrations not want to crack the weld of the two pipes?
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Post by tripletriplenut on Jan 1, 2012 11:54:09 GMT -5
3 pipes and no they will be fine they are not under any tension.
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Post by teazer on Jan 1, 2012 12:15:34 GMT -5
so what problems are you having with spent exhaust gases? how is your design of the header screwing up the sound waves? Three into one chambers return the stuffing wave at the "wrong" time for the other cylinders once it gets up to peak revs unless the pipes are designed to resonate at non peak revs (counter intuitive). The problem I had with the existing system is headers are way to long and the body is too small, so it restricts gas flow as well as being the wrong length. I'm speculating that the long headers and "wrong" lengths are to create a pipe resonance that has less negative impact after peak. I use Bimotion and Mota software for single pipes but have nothing for three pipe designs. MOTA correlates pretty well to real world changes but so far I have been unable to tweak it to work well on a three into one pipe. Do you have a 3 into 1 module? This evening I'll try some new numbers for a fatter pipe using the collector as one step and then use normal angles from there to provide appropriate wave formation on a larger scale than with single pipe for the same motor. Headers will be straight pipe and short and the collector is 63mm outlet over 114mm length. Fatter would be better on a 4 stroke collector (12-15 degrees) but on a 4 stroke a collector is basically the open end of a pipe and generates a strong wave front which I want to reduce somewhat to bring the rest of the pipe into play. On the GT, there have been many 3 into 1 systems and I have yet to see a dyno comparison to stock or chambers. TCE make a very short fat system and JollyMoto make a very long one. No dyno charts to compare results though.
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Post by teazer on Jan 1, 2012 12:21:25 GMT -5
What I should have done when I had a few pipes to test recently was to test pipe temps at different points along the pipe to see where it was choking. I have a couple of alternate stinger/baffle designs to try when it gets warmer. That may reveal if it is the back end of the pipe that's the restriction and if not at least it eliminates one variable. And with a stinger in a 3 into 1, it should sound outrageous - I may try that combo at Martin next year if it doesn't cost too much power just for the sound. It won't be fast but it might sound good.
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Post by borntoride on Jan 1, 2012 19:40:54 GMT -5
Interesting project. Would put springs on manifold like here attached Attachments:
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Post by borntoride on Jan 1, 2012 20:04:13 GMT -5
or maybe im wrong because here a 3 to 1 set without the springs and i think it look pretty much like what you are making. Attachments:
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