"True" Dual exhaust on a chinese 80cc

Discussion in 'Performance Mods' started by Lolokustoms, Dec 30, 2010.

  1. Lolokustoms

    Lolokustoms New Member

    I'm looking to make a custom exhaust that splits into two pipes and fits some fishtail tips. Im goin for a custom chopper look :cool: Thing is I have no idea if its going to reduce performance or even work at all. I have all the materials and mig so thats no issue..
     

  2. Ghost0

    Ghost0 Guest

    A true dual exhaust won't gain you anything since it is a single cylinder engine but it probably won't hurt. If you want to gain performance then you need an tuned pipe (expansion chamber). You can split the exhaust after the expansion chamber to get the look you want and add two mufflers without hurting the performance of the expansion chamber. Hope that helps.
     
  3. Lolokustoms

    Lolokustoms New Member

    What if I got the attachment to the motor that splits into two tuned pipes then the fishtail tips?
     
  4. Ghost0

    Ghost0 Guest

    I suggest you read up on how a tuned pipe works and what it does then you will understand why I provided the advice I did.
     
  5. Lolokustoms

    Lolokustoms New Member

    Thanks! ;D
     
  6. cargo-master

    cargo-master Member

    Once upon a time.... I owned a used '70 HD 350 Sprint. It was a single cylinder engine w/ a single header pipe that split "Y" out to two exhausts. One exhaust was missing when I first got it. The end pipe was capped off & it ran fine. When I got the $$ to replace the missing exhaust I do not recall the performance changing. I was young, dumb & content then. 'Cept for the years, seems there's not been much of a change in me.
     
  7. Ghost0

    Ghost0 Guest

    Ah but the 350 sprint was a 4 stroke, completely different than with a 2 stroke as far as exhausts go.
     
  8. Lolokustoms

    Lolokustoms New Member

    What's the main difference tho?
     
  9. Ghost0

    Ghost0 Guest

    A 4 stroke has valves so to get performance out of a 4 stroke you want the exhaust to breath so straight pipes are the best, look at a top fuel drag car, if there was performance gain on a 4 stroke by doing anything other than that they would do it. A 2 stroke does not have valves so there are some inherent inefficiencies in the system. An expansion chamber uses the pressure waves coming from the exhaust traveling at a certain speed then being slowed and sped up depending on the shape of the chamber to act as a valve keeping excess fuel and air being expelled out the exhaust before it is burned. The length of the pipe will determine when the pulse reaches back to the exhaust port which is why length is so critical with an expansion chamber. Like I said you could read for days on the subject of 2 stroke expansion chambers. Lots of math and calculating to do it right.
     
  10. Lolokustoms

    Lolokustoms New Member

    Ohhh okay...cool :)
     
  11. motorpsycho

    motorpsycho Active Member

    you can split the exhaust right at the cylinder by making a Y with a flange that will bolt to the cylinder. then run 2 separate pipes off of the Y. this of corse would be for regular pipe, not an expansion chamber. it would look cool, but it wouldn't give you any more or less power.
    if you are looking for power, you need a good expansion chamber because they act like a supercharger in a sense, and in a single cylinder you only need one expansion chamber. trying to run 2 expansion chamber would be a waste of time and money. if you really want dual exhaust AND a power gain, get an expansion chamber, and then split the exhaust after the chamber and run 2 pipes.

    if you don't know the difference between a 2 stroke and a 4 stroke, you need to do a lot of research. again , it amazes me how many people get into this hobby without doing any research before buying an engine. then, when they get the engine, they have no idea how it works, how to tell when it's running right, how to tune it, gas-oil ratios, all that stuff. but on the other hand, that is what this site is for.
     
    Last edited: Jan 1, 2011
  12. Lolokustoms

    Lolokustoms New Member

    I'll see if I can make an exhaust get an exhaust with an expansion chamber that connects to a y pipe for the dual tips that I want. If I can't do it then I'll just do the y pipe that has a flange to connect to the cylinder. I wont worry too much if I'm not losing power that's ok. I'm tryin to research as much as i can so I can get the most of this engine without breaking the thing.
     
  13. ken murphy

    ken murphy Member

    just get one of those poopoo pipes n split it
     
  14. Lolokustoms

    Lolokustoms New Member

    Would that provide enough pressure to have the same effect as an expansion chamber?
     
  15. motorpsycho

    motorpsycho Active Member

    no, A poo-poo pike is just an extended regular pipe with a muffler on the end, An expanson chamber is a whole different animal at it will really wake up your engine.
     
  16. Lolokustoms

    Lolokustoms New Member

    O okay..I'm looking to get some performance out the engine that's why I asked...if i can't manage to fit the expansion chamber on my bike,ill consider it though! I apreciate the help.
     
  17. ken murphy

    ken murphy Member

    Pike?.

    I dont know what a pike is,yes I do agree about a tuned pipe though.I ditched the regular stock pipes on my first build,I do agree w/you they do help let the engine breath and re burn I call it.
    I simply mentioned the poopoo for astetics,Knowing that it probably would never happen.
     

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    Last edited: Jan 13, 2011
  18. motorpsycho

    motorpsycho Active Member

    ooops...pike...lol.
    i meant pipe!!
     
  19. Dave C

    Dave C Member

    The second picture; is that a modified stock pipe connecting up the motor to the chamber? Looks like that might be a solution for me.:cool:
     
  20. ken murphy

    ken murphy Member

    fabrication

    Yes I've tried other connections to the cylinder exhuast port but the stock mount seems to work best,Its just that I mount my engines with differant types of rubber bushings for vibration so the brace for the pipe has to be mounted sum what the same way,as to avoid leaks.
     
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