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Discussion Starter #1
I scored this pipe.



All hand- rolled and welded stainless steel. The TiG welding is excellent and the muffler is dimensionally an exact copy of the TW, right down to the proper stagger, so I don't think it was ever intended for an XT or TTR.



Really nice work. The pic doesn't do it justice. No markings on it whatsoever, so I'm guessing it's a one-off. The endcap is retained with a drillable stainless rivet.



Do any of you longtimers recognize it having been made either commercially or by/for one of us in the past, perhaps?







 

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Discussion Starter #3
It's bootyfool. When I get through with it it'll look like my way cool and groovy TTR headpipe. Then I'll hope to heck it ambers out to that lovely straw color, cuz I hate shiny stuff. I can get the headpipe to the color I want in a 600 degree oven, but the danged muffler won't fit. Anyone got the keys to a pizza joint?:







You may recognize the pipe. It's the one I won't sell ya. So, neener




Actually they're prolly a dime a dozen on eBay.
 

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Your trying to squeeze every ounce of horsepower out of that little guy arnt ya
 

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Discussion Starter #5
Stainless makes things almost as fast as green paint does.



I'll sell you 20mph for 20 bucks a can.
 

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Discussion Starter #7

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I scored this pipe.



All hand- rolled and welded stainless steel. The TiG welding is excellent and the muffler is dimensionally an exact copy of the TW, right down to the proper stagger, so I don't think it was ever intended for an XT or TTR.



Really nice work. The pic doesn't do it justice. No markings on it whatsoever, so I'm guessing it's a one-off. The endcap is retained with a drillable stainless rivet.



Do any of you longtimers recognize it having been made either commercially or by/for one of us in the past, perhaps?







I have seen them in Japan on old Yamaha TZ350's.
 

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Discussion Starter #9
Tz's were two strokes, but this construction method is similar to an expansion chamber, a series of cones welded together. Quite a bit of time and skill went into this one, so it's an interesting item. Most TW types would go out and by an aftermarket noisemaker rather than build something this sensible, but labor-intensive. LOL



It's lack of markings and USFS approval stamp will be a problem around here, so I've rethought using it. I'll prolly hang it up til I build a street-oriented TW.
 

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One set of USFS markings coming up: http://www.google.com/products/cata...=X&ei=RUsPTvKHHYmDtgfE0sj5DQ&ved=0CGwQ8wIwAQ#



Sweet piece of work. 4-strokes can fatten the powerband by manipulating the pressure and sound waves in the exhaust, with little loss of peak power output. Such an exhaust assumes a megaphone shape. Tapering the outlet is a part called a reverse cone that slams the sound waves together, creating an echo that travels backwards up the pipe and arrives at the exhaust valve near the end of the valve overlap period, efectively stopping crossflow from a long overlap cam (necessary for high rpm power) and increasing torque at low rpm. At moderate rpm, the reflected sound arrives after overlap and has no effect. At high rpm, the reflected sound bounces off the exhaust valve just before it opens, creating a low pressure area in the port, aiding scavenging, and restoring most of the high rpm output lost to the restriction of manipulating the sound for low rpm torque. Every Japanese 4-stroke single motorcycle I've ever owned was fitted with such a tuned exhaust. The shorter and fatter the headpipe and megaphone, the higher up the powerband shifts. The longer and skinnier the headpipe and megaphone, the lower the powerband shifts. This is old tech, and was well-understood as far back as the early 1960s.



For instance, my first wife's 100cc flattracker didn't come on the cam until 7,000rpm and pulled to almost 13,000rpm with a straight pipe. This worked great on the 1/3 to 1/2 mile ovals we raced. Rpm of peak power could be adjusted by using different length pipes. Problem was, shorter tracks with sharper corners dropped the bike off the powerband, if it was geared for maximum speed on the straights. Some of the short tracks were little more than two piles of tires 100 feet apart. Switching to a reverse cone megaphone widened the powerband enough to have good pull out of the corners, though slightly less straightaway speed, but an overall quicker lap time.



Yes, a straight pipe will make more peak horsepower, and a good low-restriction mufflet won't have much effect, but a reverse cone megaphone will make a wider powerband, be easier and more laid back to ride, and in any situation except a wind-to-redline drag race, be quicker out of the corners. Different strokes for different folks.
 

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Discussion Starter #11
I knew someone would appreciate it. LOL.



I'm a little tired of watching folks plop down a zillion dollars for pipes which are little more than noisemakers, which force you to tune YOUR bike to THEIR pipe, often with little benefit when even the stock pipe at least does something constructive with the pressure waves.
 

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I knew someone would appreciate it. LOL.



I'm a little tired of watching folks plop down a zillion dollars for pipes which are little more than noisemakers, which force you to tune YOUR bike to THEIR pipe, often with little benefit when even the stock pipe at least does something constructive with the pressure waves.




Ok Liz send the pipe to me and I will test it with my NEW TW 249cc and will let you know how well it works! With your TW 196cc, well will it really put it to the test?????



Ronnydog
 

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Discussion Starter #13
I've never really liked you
 
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