Bicycle Boost Kit

Discussion in '2-Stroke Engines' started by gearhead222, Mar 6, 2011.

  1. gearhead222

    gearhead222 Member

  2. motorpsycho

    motorpsycho Active Member

    lol, i tried one and got nothing out of it...a total waste of money.
    BUT, boost bottle have been proven to work under the right circumstances. I really have no idea what all needs to be done to get them to actually work, but just buying one and bolting it on usually does not give you any gains from what I have read.

    In case you don't already know, a boost bottle is nothing but an empty canister (usually made out of pvc type plastic or aluminum,) with a fitting screwed into the end. another fitting gets screwed into a hole that you drill and tap (and an angle no less) in your intake manifold (or you buy a billet intake that is already drilled & tapped for a boost bottle fitting).
    then extra fuel vapor that is spit back out of the intake manifold is supposed to be stored in the boost bottle. when you give it full throttle, this extra fuel vapor is supposed to get sucked back into the engine to give a supercharged effect. I personally have never seen one work.

    I think a better, proven bolt on performace addition would be to go with an expansion chamber. You will get immidiate results from an expansion chamber and it's pretty much a simple bolt on mod. that has been proven time and time again to boost performance.

    You could pay $20.00 for a boost bottle and maybe get nothing out of it. Not to mention that you will have to drill and tap your intake manifold. Or you could spend more money on a pre-drilled & tapped billet aluminum intake manifold. Oh by the way, the billet aluminum intake manifolds that I have seen are not bent like the stock intake manifolds are. The billet ones are straight and are shorter than the stock ones, which will change your carb placement slightly (possibly requiring a longer or shorter fuel line, and the float bowl will be closer to the clutch cable stand-off that is located under the carb. on the crank case.
    This stand-off will more than likely need to be removed, cut down and re-installed for clearance.

    OR you could pay $50.00 - $70.00 for an expansion chamber, and you will be guranteed to get a performance boost. Of corse you would have to tune the head pipe on the chamber but that's nothing more than cutting the pipe to the length that gives you the performace that you want. I have never done this, so please don't ask me how long the head pipe should be. (i'm specifically talking about the s.b.p. expansion chamber).
    I got an expansion chamber from spooky tooth which is already tuned, so it's a simple bolt on, but i had to make a baffle for it.
    This is just my opinion on the subject tho.
    Last edited: Mar 6, 2011
  3. gearhead222

    gearhead222 Member

    Thanx for the quick reply! Your reply confirms my suspicions:)-Gearhead
  4. motorpsycho

    motorpsycho Active Member

    wel, that's just my opinion so you may want to see what others think about this before taking what i said as being the facts.
  5. shell shock

    shell shock Member

    i think that your consensus is pretty much uniform throughout the site. though you still get those who swear by it. to each there own.
  6. MikeJ

    MikeJ Member

    Let's see.... These are 2-cycle engines; some dirt track bikes are 2-cycle engines. SBP provides tuned exhaust pipes; the most competitive dirt track bikes use tuned exhaust pipes if allowed.

    Do dirt track bikes use boost bottles? I have never seen them available for dirt track bikes. What do dirt track bike builders know versus what is being flaunted by boost bottle sellers?
    Last edited: Mar 7, 2011
  7. motorpsycho

    motorpsycho Active Member

    actually, KTM 2 stroke dirt bikes come from the factory with boost bottles, so that proves that they can work.
    The part about getting them to actually work is a bit of a mystery tho because there's more to it than just bolting one on.
    I personally have not had any success with boost bottles.
    expansions chambers are a simple bolt on that are proven to work without any mods. required.
  8. bossman

    bossman New Member

  9. Dave C

    Dave C Member

    I had a Roost Boost bottle on my '84 Suzuki RM250 powered Super Kart..21 years ago is when I was racing it. The man who built it owned a cycle salvage yard. There was nothing on this Kart that didn't need to be there. In the case of a boost bottle it comes under the heading of "the sum of all the parts". Add one to a stock motor and your not going to feel any difference, except maybe a smoothing out of the way the motor runs. Start getting a package of mods going and it makes it's presance known more.

    All I can really say is the Boost Bottle was one of the first mods I did to my bike:helmet: