Ram Air System! Easy to make. :)

Discussion in '2-Stroke Engines' started by Joely Poely, May 25, 2011.

  1. Joely Poely

    Joely Poely New Member

    Check out what I made the other day. Its easy to make and it does add some ponies to your motor. Tell me what you think and also suggestions on how to improve it. Maybe a supercharger...have you seen those induction electric motors used in remote control jets? Just ideas.

    Low end grunt picked up a little bit making takes off's feel more linear versus jerky. The real noticeable differences was at top speed where the engine revved freely and didn't feel like it was studdering because the carb was searching or starving for air. I would say it picked up about 3-5mph more on the top end.

    Im still going to add a tube to connect to what I have already installed that runs along the top tub of the frame to the front of the bike to put a air scoop to catch more air. Im trying to think of a way to some how cause a venturi effect in the air entering the Ram Air system that would cause a "twister" type effect in the air entering causing the air to travel faster to the carb.

    I still need to do the muffler modification to make it less restrictive to the exhaust coming out.

    I really want to try to make a super charger with a remote control airplane air duct motor. I think it would be easy to make. I have a ton of RC stuff, minus the air duct motor.



    Here's the youtube video of how I made a Ram Air System. :)

    <iframe width="560" height="349" src="http://www.youtube.com/embed/RMm6CffYups" frameborder="0" allowfullscreen></iframe>
    Last edited: May 25, 2011

  2. nvmextc

    nvmextc New Member

    So simple, yet genius! I'm making some this weekend :) Thx for sharing
  3. DuctTapedGoat

    DuctTapedGoat Active Member

    Nice job - But I would look into reducing the pipe size so you don't have it coming out of the frame like that. When you look at it, your air intake is only 3/4" to 7/8". The reason it's so large is so that there's a larger area for the filter - so you can get away with reducing the size.

    I think what would be better for an air ram would be to braze a cone/trumpet on a 180 pipe that gradually reduced from the same size you have. Should give increased results, as right now, it's not gradiated, it's going from a large amount of area immediately to a small area.

    Something that's been somewhat commonly done is reversing the jug to get the same effect. Granted, it doesn't cool as well though.
  4. Joely Poely

    Joely Poely New Member

    This is the kind of electric ducted fan motor I would use if I wanted to make a supercharger set up. Maybe set it up with proportional switch next to the throttle that I can adjust with my thumb while Im riding the bike. I would be able to adjust how much "supercharger" effect to get to the carb. The guy in this video is doing it with a remote control so it is possible to adjust the motor RPM. Any ideas on supercharging anyone??

    <iframe width="425" height="349" src="http://www.youtube.com/embed/qVVrMWOZz08" frameborder="0" allowfullscreen></iframe>
  5. Joely Poely

    Joely Poely New Member

  6. HeadSmess

    HeadSmess Well-Known Member

    so far, either its my net or my net, i cant see no vids.

    but, um. hate bursting your bubble. its a two stroke. you cant supercharge it. thats what tuned intakes and exhausts are for. a self contained ram air unit :)

    sure, people go and stick blowers on two strokes all the time. youtubes full of em. they dont consider crank seals, air flow, over a hundred years of hard won experience...

    so if theyre so good why isnt every factory manufactured bike since whenever, been fitted with one? like say, cr250's.... why bother with that silly fat exhaust thats hard to fit into the frame??

    cus thats what they need to do anything.

    ooop, retractment. the vids have appeared. but, even if my net was workin i wouldnt bother.

    am i being rude? yep :)

    for the best reasons. waste your time on these things instead.

    one. find "two stroke tuners guide" by gordon jennings. google two stroke tuning etc. read til your eyes are watering. anything related should also be read. also, dont go expecting 15000rpm redlines... keep reading :)

    two. get a welder. tig. learn to use it.

    three. find out more about tuned pipes and intakes. this is what the welders for.

    while youll hate me right now and im sure will have much sound advice to give to me in return, in the long run. youll be glad for the knowledge:)

    toodles :)
  7. motorpsycho

    motorpsycho Active Member

    ummm, technically you can supercharge a 2 stroke.
    Just look up a detroit diesel 8v92 engine, detroit diesel 6v92 engine or a detroit 12v71
    they are all 2 strokes, with a roots style blower AND a single or twin turbo in some cases.
    these engines are used in firetrucks, semi trucks, boats, and sometimes in tour busses.
    here's a 6v92 (v-6, 2 stroke diesel). look close, you will see a blower on top of the engine and a single turbo at the rear.

    here's a detroit 12v71 (v-12, 2 stroke) twin turbo.

    here's a detroit 8v92 (v-8, 2 stroke) twin turbo with a blower. Look close, the blower is low profile on top of the engine.

    on the other hand, those are v-6. v-8 and v-12, 2 stroke diesel engines, not a wimpy, cheaply made chinese 2 stroke.
    I actually don't think the crankshaft, connecting rod or bearings on these little motors could handle any type of boost.
    Last edited: Jun 15, 2011
  8. HeadSmess

    HeadSmess Well-Known Member

    dont confuse the issue.

    what about napier deltic? thats no poxy v6, v8 or v12. not with 18 cylinders and 36 pistons...

    diesels are diesels and i wasnt talking about diesels. the air never enters their crankcase.

    what i was saying, rudely, was that theyre are tried and true methods for making a (petrol) 2 stroke perform, and mucking around with ducted fans is not it.

    p.s. ducted fans also make little if no BOOST. static thrust and the action reaction force of moving large masses of air has nothing to do with air PRESSURE. stick a ducted fan in front of a sealed chamber, and you may get 1/2psi extra pressure, no matter how hard you spin the fan. the air isnt moving, fan stalls, no pressure.

    real turbo chargers are CENTRIFUGAL. this speeds the air up. THEN, the air is held in a volute, the snail. this is where air velocity is converted to air pressure....

    anyways, ill say it politely this time.

    save your time and money, and pride :p find out what makes two strokes tick and people will PAY YOU to do (sensible) things for them... :)
  9. hi here is my setup it's form a old stock exhaust and a sink trap the bolts on the exhaust match up to nt carbs filter bolt holes nice but i do want to put a cone on if i can find one becrause the filter cuts down the air flow

    Attached Files:

  10. My guess is just cutting out the back side of the filter would do the same thing. I did that to my bike and picked up 3.1MPH on the top end. That was the last thing I did though.
  11. RdKryton

    RdKryton Active Member

    A little bit of info here.

    Looking at your setup you may be putting a little more air into the intake. This is causing the engine to run leaner. Lean = power but also lean = heat and heat is the enemy of these cheaply made 2 stroke engines. By forcing air into the carb you are shutting off the vacuum that pulls fuel into the air flow through the carb. You have now just leaned out your engine and as I said before, lean = heat. Less fuel also means less oil for lubrication. See where I'm going with this? I'm not being negative, I just don't want you to kill your engine because you didn't have all the info. Now the good news. If you raise the needle one notch in the carb ( move the clip down one groove) you may be able to get the fuel you need for a proper mixture, lubrication, and cooling but if the intake pressure is too high this will have no effect.

    Good luck

    Last edited: Jun 18, 2011