do expansion chambers really work?

Discussion in 'Performance Mods' started by Bikeuser, Jul 16, 2008.

  1. Bikeuser

    Bikeuser Member

    title says it all. I don't think expansion chambers work for the low RPM's HT engines make. if you have experience with an aftermarket exhuast chime in.

  2. I have to disagree I put one on my 48cc HT and I love it. I paid all of $20. including shipping, so I wouldnt lose much if it didnt work. I dont know that it does much for the high end but low end torque is unbelieveable.. I have been told the reason the low end is good, and the high end is not like it should be is I am running such a long header. I am now in the process of dialing in a 18mm mikuni carb. It is sooooo much better than the stock carb, so much smoother, and I believe I will be able to pickup the top end when I get the jetting right...
  3. fastboy9

    fastboy9 Member

    Yep, I love mine! It looks great but the low end torque is excellent! I've got a 44 tooth sprocket on the back and with WOT and a bit of pedalling you really have to hold on quite a bit from the acceleration. Each expansion chamber is tuned perfectly to the engine it is designed for, so you cant just stick on any old pipe, your best bet is fitting a pocket bike pipe to it if you have a 48cc, thats your closest bet.

  4. Hi,

    Yes, A properly designed tuned pipe / expansion chamber will make for remarkable power increases on any 2 stroke....HT included! ;-)

  5. Ghost0

    Ghost0 Guest

    They are far and away the most cost effective means of getting performance out of any 2 stroke. As long as they are set up correctly. If they are not they can be worse than the stock pipe.
  6. Mountainman

    Mountainman Active Member

    if the excessive noise is not a concern -- riding them on the street - not sure - they help our MB image ??? -- usually a great way to increase speed... Happy Riding from - Mountainman
  7. BSA

    BSA Guest

    Surely if you had more low down torque you could just use a much smaller sprocket, thus saving excessive engine wear at high RPM's.