SBP chamber + stock header pipe ?

Discussion in 'Performance Mods' started by danlandberg, Apr 7, 2010.

  1. danlandberg

    danlandberg Member

    Has anyone had to use the two together? I have a SBP chamber, But it will not fit (with the pieces that come with the chamber), MICARGI DIY kit I got from BBerry! (down pipe or up). But I hold the chamber next to the stock pipe and I think I can get it to fit. Even though The I.D. of the stock header pipe is smaller. The chamber would be about where the stock muffler is. (out front) and hard to tune for a specific bower band. Would like some input! I have seen some long pipe from exhaust port (cylinder) to chamber, having the chamber far rearward, away from and behind everything. I under stand the workings of a chamber but have not yet learned the tuning part (for power band adjustment)! Anybody help out here? ANYBODY?...........Dan :confused: :sweatdrop:
     

  2. give me vtec

    give me vtec Active Member

    yep... it works.

    [​IMG]
     
  3. Fabian

    Fabian Well-Known Member

    Hi vtec,

    It's good to see someone posting clear, in-focus and hi-res photos.

    Cheers Fabian

    ps the engine, tuned pipe and red frame looks good.
     
  4. Ghost0

    Ghost0 Guest

    Obviously from the photo it can be done but the critical tuning item is the distance from the exhaust port to the expansion chamber. 12 inches is a good start. People running an expansion chamber 2 feet behind their bike are defeating the purpose of the expansion chamber. Now true you can design one to work at that distance but the shape and diameters would have to be completely different.
     
  5. give me vtec

    give me vtec Active Member

    the stock tail pipe was actually pretty close to what you guys gave me... it actually worked out great.

    I ended up ordering two different pipes from you. The chrome one seemed to be smaller than black ones you guys are selling now. If I remember correctly... the newer black one didn't work as well as the chrome one with cut exhaust pipe header.

    Why did you guys change them... are there two different models??? The only thing I could think of was different production runs, or one was made for the 49 cc and one was made for the 69cc.
     
  6. Ghost0

    Ghost0 Guest

    We have made no changes to the pipes other than one run had a smaller muffler diameter and we have made some slight mods to make the pipe sections fit better but there have been no changes to the expansion chamber design, pipe diameters or lengths.
     
  7. give me vtec

    give me vtec Active Member

    ...thats what i was talking about, the muffler dia.
     
  8. danlandberg

    danlandberg Member

    GhostO, You say 2 feet (24'' from ex. port to chamber)? I need to use the stock header pipe. (It's the only way I can make this thing fit!) and it is only 8.5'' from top of ex.port to muffler. (outside radius measurement, is the longest.) I think if I have to go shorter, it will change where the chamber has to be! And not sure what power band I would be in! I would like the power band full range, but that probably won't be possible! I guess i'll just have to try it!!! Any one with advice? ....................................DAN
     
  9. danlandberg

    danlandberg Member

    V Tech, That is a nice looking chamber set up!!! That's what mine should be/look like. (I hope it comes out that nice) How did you secure the chamber ti the frame? Except mine will be chrome to black. What is your header length, and what cc is your engine. Oh, and what is the chamber off of? Where did you get it?
     
  10. give me vtec

    give me vtec Active Member

    I think he was saying that people with 2 feet of piping defeat the purpose of the chamber. I believe your exhaust piping should be 6 - 12 inches from exhaust port, to chamber.

    I cut the header off about 1/2 inch after the bend.

    69cc grubee skyhawk.

    To tie it to the frame I used a coat hanger, and a couple of zipties. I bent the hanger to shape and then secured it to the screw that holds the fender on. The zipties keep it from sagging.

    Its a sick bikes chamber... they dont sell the chrome ones anymore.
     
  11. danlandberg

    danlandberg Member

    That's what I thought! In a post above, '' 12'' is a good starting point''. I'll be starting with 8.o'' because I'm going to cut .5'' above mufler, (In case I have to sleeve and weld it back together). The longer the header pipe, the harder it is for sound wave to return to ex. port for optimum scavenging! :thinking:
     
  12. Ghost0

    Ghost0 Guest

    First, the critical distance is from your exhaust port on your engine to the beginning of the expansion chamber, the muffler has nothing to do with this. Our pipes are designed to work at around 12 inches plus or minus an inch or so for tuning. Altering it 4 inches, shorter, or 12 inches longer, making the 24 inches I noted earlier, will be detrimental to the proper tuning of the pipe. It is all about timing and the speed of sound. 24 inches doesn't make if harder for the sound waves to travel it just takes longer which is why it destroys the tune of the pipe. For the sake of example, if you went to 24 inches. The timing of the sound pulse would be delayed to the point that your exhaust port would be closed by the piston when the sound wave is supposed to close it. This will defeat the purpose of the sound wave closing the exhaust port when it is open keeping the unburnt intake charge from leaving the combustion chamber creating a better more powerful combustion. So say you go with the 8 inches you are looking at. At 8 inches the pulse would hit the exhaust port too early and do approximately the same thing. A 1/4 inch difference in header length can make a difference in power band so I hope this explains that 4 inches from the recommended 12 inches will be well passed the effective length to make the most power out of your engine. Will it run better than a stock pipe? Yes, but are you really taking advantage of what a tuned pipe is supposed to do? No
     
    Last edited by a moderator: Apr 9, 2010
  13. danlandberg

    danlandberg Member

    Thanks Ghost, Like I posted before, I do no YET how long the header will need to be. If your chamber is set up for a 12'' header, I'll have to add 4'' to the stock pipe. And see how it works. If I want a low end-mid range power band, do I go longer or shorter? This is a learning experance for me. And I love to learn what is right and wrong!!! (Frome people who know)!!!
     
  14. Ghost0

    Ghost0 Guest

    Longer equals more torque and shorter equals more top end.
     
  15. danlandberg

    danlandberg Member

    Thanks Ghost Like I said it's a learning thing. (and I want to learn) What increments at a time?
     
    Last edited: Apr 9, 2010
  16. Ghost0

    Ghost0 Guest

    Like I said 1/4 inch can make a difference but you are pretty safe working 1/2 inch at a time.
     
  17. danlandberg

    danlandberg Member

    I'll start out with Adding 4''. I want mid to top end power :D, but I'm in the break in period right now. After break in :thinking:, I'll cut as I go!
     
  18. AussieSteve

    AussieSteve Active Member

    Dan, you need to stick to Jim's 12" recommendation, then tune the pipe itself for the rev range that you're after.
    Especially, don't use a 2 foot header or you'll waste the tuned pipe.
    (Yep, I'm still alive. Just thought I'd poke my head in for a look-see.)
     
  19. danlandberg

    danlandberg Member

    Good to hear from you Steve! I'll have to add 4'' to the stock pipe to get to 12'' Going to try it this week!
     
  20. danlandberg

    danlandberg Member

    I tie wrapped the chamber on, to get an idea of where it needs to be. (but from the bolt flange to the chamber is 11'') The question I have now is, Will the silicone tubing hold up with out the header pipe inserted into the chamber? (the tubing is about a 1/2'' extension added to the stock pipe). It allows some flex for alignment. I'll post pics later!
     
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