I clicked on the link and didnt see a sticky on x chambers. as far as self adjusting pipes, they already make x chambers with tromboning headers. they self adjust with the rpms to stay on the pipe all the time. there are also other ways to widen your powerband. you can insulate tye chamber for higher rpms and liquid cool your header for lower rpms. you can increase or reduce back pressure. the size of the stinger also has an effect. big stinger=lower rpms. small stinger=higher rpms. search expansion chamber on wikipedia for more detailed explanations.
How do you tune an Xchamber?
- Thread starter Texhun
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the more back pressure the higher rpms the pipe will kick on at. I have a question though. what would happen if you removed the stinger? as far as I understand, the grubee banana pipe has no silencer. I have a smaller x chamber that was made for a pocketbike. so what if I kept my tailpipe but removed just the silencer? would I still maintain enough pressure to maintain my timing? or would I lose that?
Well, the banana pipe doesn't need a long stinger, as it's got a very short head pipe. It doesn't kick in until very high RPM is reached to begin with. As well, the reason it doesn't have a silencer is that it's a very quiet exhaust. By removing the silencer, you're really just shortening the stinger, so expect that to come off of your top end.
Heres a pic of my idea I know its a poor drawing. But I could use the cat out of the stock muffler for the end cap just drill out for better air flow and hold the spring in place. The cap is from the stock stinger just ground to slide back and forth with the spring on the nozzle, Just I'm not sure where I could get spring that long and weak enough to let the cap be pushed back. And as for the new stinger I'm debating whether to use the stock gutted muffler body, or to use a piece of actual exhaust pipe.
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This is kinda working backwards - you're in a sense, shortening the stinger as the RPMs increase, when you'd want to increase stinger length as RPMs increase. That would give you an autotuning exhaust.
Yes it would be increasing the length as the RPMs go up and shortening as the RPMs go back down ,sorry maybe it was my poor drawing skills and explainatory skills that got you thinking that lol! 
However what are your thoughts on how long the stinger should be I know for sure theres a max length I just don't know how long, I'm guessing no longer than 14".
However what are your thoughts on how long the stinger should be I know for sure theres a max length I just don't know how long, I'm guessing no longer than 14".
I'm thinking it's a lot of trouble for not much. The sbp pipe already makes pretty good power everywhere in the power band.
Most of the china girls I've ridden already go faster then is safe for most bicycles on the top end. Where they could use a performance improvment most, is lower down in the power band, especially after you gear them up.
Most of the china girls I've ridden already go faster then is safe for most bicycles on the top end. Where they could use a performance improvment most, is lower down in the power band, especially after you gear them up.
Yes the power band is very good on the SBP pipe, but if you have excellent lower end already why wouldn't you want to increase the lower even more and the top end, not trying to sound like a jerk or anything just trying to get the most out of the pipe, even if you gain only 3-4MPH I think it would still be worth it I think the engine would run smoother too. And I think it would be great for a 36T or even a 32T it would be crazy good for a 44T and a 41T. And as for the safety on the bike, well, not trying to sound dumb but, on a 10 mile stretch of flat road with almost no traffic and riding the shoulder I don't think it would be to bad considering I'm wearing a helmet and everything.
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yeah this is just a theory. its a lot of work to figure it out when they already make tromboning headers that are designed for the same results that you are describing. not trying to sound like a jerk, but even if your idea does work, its not a new idea. I did state about the tromboning headers before as well as several other ways to widen your powerband, but absolutely no one paid attention to me. tromboning headers. what else can I say?
Hey I own a set of bagpipes lol. And bbbean I know this has been invented a looooong time ago, but tromboning headers on a motorized bike atleast mine it just won't work, the stinger is the only thing I can really mess with on my exhaust since it's not welded solid, get my point. And as far as I know, no one has tried the idea on the stinger on these china 2smokers, and really there is a lot of room to tinker with very little money spent, sure I very well may put 8 hours into this thing but if it works it was worth it and if it dons't well that's one more false upgrade to worry about, that's my view on it. I'll start my design and try to put it together sometime in the next week or so I'll keep everyone posted.