Boost Bottle or Expanzion chamber; What's best for $ and power?

Discussion in '2-Stroke Engines' started by 805lazy, May 6, 2010.

  1. 805lazy

    805lazy New Member

    I already put the 32 tooth sprocket from spooky tooth on my happy times. I like the increased top speed, but it has a little less pull up hills and the bottom end, I need more POWER! I have a limited budget and want to eventually get both, should I get the boost bottle kit right away or hold off till I can afford an expansion chamber and get the boost bottle later? What have people experienced with either one or the combination of the two?

  2. Apachekid

    Apachekid Member

    I would get the expansion chamber first. Thats an immediate power boost in low and mid range, something like another third more power,for me. Personally I'll never run without an expansion chamber. Id also do some porting on the intake and exhaust before I went to boost bottle...but thats just me! Cheers :jester:
  3. Al.Fisherman

    Al.Fisherman Active Member

    I make my own boost bottles, although some can't tell the difference when installed, I can on the ones I built. But everyone installing an expansion chamber says there is a BIG difference. I haven't ported, but from my automotive experience, porting helps...that is why ALL race cars are ported among other things.
  4. Pablo

    Pablo Motored Bikes Sponsor

    Chamber, no contest.
  5. AussieSteve

    AussieSteve Active Member

    Yep, a boost bottle doesn't compare to an expansion chamber for performance increase. Two strokes need a tuned pipe to work properly.
    I'd love a chamber, but I'm concerned that the cops in this neck of the woods might consider it too motorbikeish. (Not a word?)
    I've been seriously considering risking it anyway, but so far the law never takes a second look at me and I'd like to keep it that way.
    All the same, (Paul), you never know, I might add one to my next order. Not sure if I can resist.
  6. danlandberg

    danlandberg Member

    Steve you won't regret the X chamber! My bike accelerates up hill & I can take off from a dead stop with no peddling. :D I think it's time for a 32 tooth sprocket. I have a need for speed! :whistling: But got to fix broken rear mount studs (happened again on the second engine) Got 4 studs to fix now! :ack2: Beside the bad frame angle, :thinking: it might be a torque issue with the X camber! It's a never ending battle!:banghead::smash:
  7. AussieSteve

    AussieSteve Active Member

    Yeah, Dan, I'll probably buy one, just to perfect the build. It's one of the few things missing at this stage - that and a carb.
    I'm not riding much now, but I still want to finish what I started, even if it just becomes a trophy.
    I don't think I'd bother with a boost bottle, but a tuned pipe makes a big difference.
  8. danlandberg

    danlandberg Member

    Carb + x chamber

    The speed carb for the 66/80cc engine + the x chamber make a big differance. :D Fuel econamy went down but power went up! (Go figure) It's well worth it!!! :tt1:
  9. give me vtec

    give me vtec Active Member

    boost bottles suck... the only thing they boost is our $$$$. I bought one and will give it to you if you pay shipping.

    Buy the expansion chamber hands down. There are a couple good ones from what I have read. I have 2 sick bikes chambers and they ROCK.

    If you dont have a slant or high comp head, the nos is fun for a couple good pulls too. USE THE NOS VERY SPARINGLY.... A LITTLE GOES A LONG WAY. I find it best to squeeze very slightly.
  10. Hajuu

    Hajuu Member

    Personally, boost is the lamest thing I can possibly ever imagine anyone doing to one of these.

    An expansion chamber has real, ongoing, tangible benefits.
  11. AussieSteve

    AussieSteve Active Member

    I agree Mike, Ron, (al.Fisherman), has a performance increase with his home-made verson, but in general I've heard almost no positive reports of boost bottles, whereas tuned pipes are well and truly proven.
    Boost bottle, (maybe) 1-2% perfomance increase if you're lucky, well tuned expansion chamber, about 5-10% improvement.
    2-strokesreally do need a tuned pipe to run well and efficiently.
    In my opinion, boost bottles are a bit of a novelty.
    If they were worth the effort, every 'port-scavenged' performance two-stoke would be fitted with a boost bottle.
    When Jap designers/manufacturers were looking for more power in the 70s, if they worked, boost bottles would have been standard on all performance 2-stroke engines.
    (Expansion chambers were standard.)
    I refer to the 70s, because that's where these engines belong, in terms of technology.

    In terms of the original question, all said and done, it appears that a boost bottle does work, but nowhere near to the degree of an expansion chamber.
    Last edited: May 15, 2010
  12. danlandberg

    danlandberg Member

    The X chamber is the bomb!!! I just repaired 4 rear mount studs (removed the studs in 2 engines). Now I have to do it again :ack2: I went to the market (about 4-5 miles 1 way) It was O.K when I got there, but when I got home, NO studs, nuts or clam shell clamp! The rear mount spacer was still there, because I put hose clamps (1 above & 1 below the spacer). With the power I'm getting from the X chamber, I have been thinking of a way to modify the rear mount. :thinking: :idea: Maybe shuffle pins or going to 8x1.25 studs. Or maybe a new rear mount system. The MICARGI bike is NOT the one to build on!!!!!:ack2: :poop: But I can't even afford a WALY WORD bike at this time! :icon_cry: Thought about a boost bottle, but what I have read, it's not the best investment. If I were to add something for more umph, :thinking: I would add NoS! It's hilly here where I live & windy!!!
  13. Pablo

    Pablo Motored Bikes Sponsor


    Why is this? (thanks)
  14. danlandberg

    danlandberg Member

    The angle of the seat tube to down tube do not match the mount angles of the Flying Horse engines! (1) The frames are thin metal (2) And these bikes should NOT be sold as a D.I.Y. Kit!!!! :ack2: :ack2: I will NOT buy ANYTHING from B.B. again!!! OH and thanks for the stickers, :D I'm almost ashamed to have them on this build :poop: :ack2: But it might get you some business (Every one likes the concept)! I think the next engine I get will be a RAW from Kings. all though they might be affiliated or have the same web designer. :thinking: THANKS again.............................Dan P.S. What inexpensive bike would you recommend? (As a D.I.Y kit):thinking:
  15. Pablo

    Pablo Motored Bikes Sponsor

    Old mountain bikes!:cool::grin5::jester:
  16. danlandberg

    danlandberg Member

    My first build was on a Royce Union. (It's in stold in Vegas, in the stolen bike forum). Made in Taiwan, but a better made bike than the MICARGI (USA) piece of :poop: Just want to ride, and can't afford to be broke down in the middle of BFUtah! :ack2: I need to mod a rear mount so I don't keep breaking the studs. After that is done, I'll be happy :D until the frame breaks in two.:rolleyes7: