Performance upgrades

Discussion in 'Performance Mods' started by pdxrhett, May 22, 2009.

  1. pdxrhett

    pdxrhett Member

    I have a bone stock Mitsubishi 49cc motor, and am looking for all possible upgrades. I've researched and all I have found are xcan exhausts and a 15mm intake. I can do a little fabrication, but not a lot, so my question is, are there any other upgrades? Preferably a big bore?? Something that will give me a lot more hp (im talking at least 2 more hp)

    EDIT: I was also curious as to what an expansion chamber does to create more HP :D
    Last edited: May 22, 2009

  2. fastboy9

    fastboy9 Member

    Where this engine is so popular for gopeds and pocket bikes there are quite a few mods available on various sites.

    Basically an expansion chamber is designed in a way that the exhaust gases will create a momentary vaccuum that will pull the mixture into the cylinder quicker at the precise perfect time. The expansion chamber will be more effective at a certain rpm, all depending on how it is tuned (dimensions of the pipe) this is known as the powerband.

    You could compare it to the effects of turbocharging as the engine will create alot more torque as the mixture is pulled quicker. The best way to explain an expansion chamber is probably this diagram!:
  3. pdxrhett

    pdxrhett Member

    could someone give me a couple links to these sites? I don't want to buy something just to find out it doesn't work.
  4. Junster

    Junster Member

    Uh sorry no disrespect intended but a tuned pipe causes a sound wave to reflect back at the exhaust port just before it closes to stuff some of the excaping exhaust (and energy) back in. The effect is to raise the compression way up when your are "on the pipe". That's why they only work in a certain rpm range and why the length of the exhaust before the pipe can be critical. Just like that link shows the intake port is already closed when the wave reflects back.
    Last edited: May 22, 2009
  5. 5-7HEAVEN

    5-7HEAVEN Guest

    I don't think there is a pipe made specifically for a 49cc Mitsubishi. You would have to WANT to take a chance to see if an X-can or snailpipe would fit.

    For starters, measure the distance between the exhaust bolt holes. Basically there is the small bolt pattern and the larger bolt pattern. The bigger one fits G62 and GP460 engines.

    I have TLE43cc engines. Fortunately their bolt pattern is a few millimeters different from the larger pattern. Using a round file enlarges the flange so it would fit my engine.

    After the modified flange bolts on, the ADA S1 pipe slipped onto my engine. However the mounting bracket interfered so it was hacksawed off.:whistling:

    THENNN, your engine will probably run lean, as mine did. Since the carbs have no low and high speed adjustments, a high-performance Walbro carb needs to be installed.

    ANNND, since there are no aftermarket manifolds that bolt on, ya need to fabricate carb adaptors.:detective:

    Do you STILL want to install a performance pipe?:jester: