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  • #16
    in this thread, we will live by the laws of thermodynamics!

    ps, can someone point me in the direction of nang powering my 50cc quad?
    and how does one know how much richer a fuel mixture is?

    haha pocketbike dragging with a 5 canister system!
    Bad Brothers Racing
    Last edited by KiM; 05-02-2008, 11:35 AM. Reason: added link


    • #17
      In theory, instead of riching up the mixture full-time, resulting in poor mixture when not on NOS, would it be possible to hook up a venturi-drawn carb-style setup for the nos line as well?

      ie - similar to an airbrush bottle connected to a hose using a t-piece - but full of fuel instead of paint... and using a carb-jet style sizing system to determine fuel metering?

      Then the end of the hose could be put basically into the carb entrance, just before the choke/throttle butterfly? The fuel canister (which would only need to be tiny - model paint tin or similar?) would want to be as close to the end of the line as possible I would think, but far enough away to avoid combustion...


      • #18
        Originally posted by Captain Starfish View Post
        Na-ah, you failz thro.

        Nitrous oxide does not contribute to the chemical process of combustion.

        Remember our atmosphere is around 78% nitrogen. Combustion of fuel causes heat, which in turn increases the pressure of whatever gasses are in the combustion chamber (mostly nitrogen) which then causes expansion via the pistons.

        Different gasses have different coefficients of expansion, ie for the same heat, different gasses will expand by different amounts. Nitrous Oxide has a much higher coefficient of expansion than boring old Nitrogen and so when the same amount of fuel burns, yielding the same amount of heat, you get more force on the pistons.

        But it don't give you more oxygen. For that you need teh turbo.
        Wrong, Nitrous oxide is a strong oxidising agent, and most certainly does react chemically with the fuel. Thus you need more fuel if you don't want to run lean.

        From what I have read, at high temps it decomposes to nitrogen and oxygen. Conditions like those you find in a combusion chamber. Thus the comments about having a molar composition of 33% oxygen.
        No amount of genius can overcome a preoccupation to detail.


        • #19
          If it works let me know. Sounds like fun.
          Feels good man.


          • #20
            Thanks to the guys who actually know something

            Every day's a school day at PSB!!!
            "Once upon a time we would obey in public, but in private we would be cynical; today, we announce cynicism, but in private we obey."


            • #21
              ^^ ahah my chemistry teacher was great in high school, he always tought us that kind of random stuff

              my awesome amazing design explained through the visual wonder of MS paint


              • #22
                POCKET BIKE NITROUS OXIDE KIT NITROS CAR TURBO NOS KART - eBay Road Bikes, Pocket Bikes, Pocket Bikes, Go Karts, Cars, Bikes, Boats. (end time 05-Feb-08 21:17:54 AEDST)

                which looks like the same as that other kit posted.
                I am sure that could be modified to turn it into a wet spray job.
                think I have an old air brush kit at home I will look for.


                • #23
                  ^^ disclaimer* I have no idea if what I posted above will work, or if your bike will simply burst into flames and result in a horrible feiry death.... it was just an idea I had (which I will probably find out later is commonplace and everyone does it and knows about it)


                  • #24
                    Ok I cannot ignore this thread any longer


                    N2O 1 mol @ stp ~ 22.4L of gas liberates 1 mol of oxygen for burning with carbon and hydrogen in petrol to give CO2 + CO + H2O

                    O2 in air ~ 21% @ stp ~ 4.5L liberates 2 mol of oxygen per mol of O2. Ratio air vs N2O call it 9L oxygen vs 22.4L for pure N2O for the same volume of gas at same temp and pressure.

                    N20 is sprayed as.a liquid not a gas. In the bottle at stp vapour pressure is ~ 700psi @ st. If u have a bottle heater or mount bottle next to exhaust ur talking about 1000psi. This is what ur spraying into ur motor, liquid under pressure not gas at stp. At this point its worth mentioning to nang heads that brain embolisms caused by sucking on unregulated N2O bottles is a very real risk at these pressures. Try not to do anything stupid in the pursuit of a cheap high.

                    Dry nos shot on fi system: design concept

                    Point fogger/nozzel at ait (that's air intake sensor). When the nos explosively evaps from liquid at 700 psi to gas at the vacuum in ur airbox it freezes the ait.

                    When ur ait freezes to like minus 20C or whatever (depends on how close u mount the fogger to ait) it tells the ecu that the incoming air is cold. Cold means denser. The ecu responds by opening the injectors to the limit of their range which means more fuel is injected to burn the extra O2 (so long as u mounted the fogger close enough to the ait).

                    If u have matched ur dry shot to the ecu range ur a/f (which is more acurately oxygen/fuel in this context) ratio will remain at a sweet 13:1 and u can spray all day long and won't lean out melting holes in ur pistons or plugs or other motor detonating issues.

                    Wet shot means u can spray a shot bigger than ur ecu range because u are adding in more fuel to burn the nos.

                    I haven't bothered to do the math cos I only spray small shots inside my ecu range. But imho if u spray a 30 shot for instance at 5000 rpm vs a 30 shot at 10000 rpm if u know anything about power torque calcs u will realise that the same size nos shot puts more load on ur bottom end the lower the rpm at which u spray it.

                    Nos is a limited quantity anyway (compared to a fulltank of fuel) so there is no point spraying it until it will make more power than ur motor would make anyway by holding it in gear for longer.. Least on a superbike that will wheelie off launch.

                    Moral is no point nosing anything else, if u want more power get a faster bike
                    Originally posted by Bendito
                    If we get to a stop and we are missing a dozen bikes and you are last, it was your fault. Don't be that guy. No one likes that guy.


                    • #25
                      ^^ I was under the impression that due to the rapid expansion and pressure drop when being released from the high pressure bottle to the combustion chamber... it reverts back to a gaseous state... and is immediately broken down in the heat?

                      in the use we are talking about (ie nangs/soda bottles) it will enter as a gas...and flow through the lines as a gas, as there is no pressurised priming involved


                      • #26
                        In ur context all ur doing is leaning out ur motor. I think CO/CO2 ratio will inrease as will burn temp. Might burn carbon deposits off ur top end. Considering how short the spray is I doubt anything will get so hot to cause damage. carb bike, 2 stroke and u woting at low rpm I guess its rich already so u probably would notice a very brief erm power surge if u don't spin a bearing or stuff whatever 2 strokes use for valves.
                        Originally posted by Bendito
                        If we get to a stop and we are missing a dozen bikes and you are last, it was your fault. Don't be that guy. No one likes that guy.


                        • #27
                          ^^ we are talking ghetto-style wet shot system here though... as per the diagram at the top of this page...

                          Theres no way I would try it...seems rather pointless.. and you'd get better gains busting out the grinder and doing some dodgy home-porting... but if you wanted to play around... it could work after some testing...until you break something


                          • #28
                            Lmao @ drawing

                            I am on mobile phone so I didn't bother to view image b4.

                            1st if nos line is pressurised the fuel line u have tapped into it will need to have over pressure or no fuel will come out.

                            2nd that looks like an excellent way to set fire to ur ride!
                            Originally posted by Bendito
                            If we get to a stop and we are missing a dozen bikes and you are last, it was your fault. Don't be that guy. No one likes that guy.


                            • #29
                              ahah yeah but its not my ride

                              fuel line wont need pressure though... venturi style the same way as a carb (in theory)...and rapid flow velocity would mean it should work quite effectively...

                              but yeah... i really dont recommend trying it


                              • #30
                                NOS Systems are working on Liquid NO2, not gaseous NO2. The idea is that when the NOS flow is engaged, it super cools the air going into the engine, making it much more dense. This allows you to cram more air and fuel into the cylinder than normally possible.

                                Ever noticed how sometimes your bike/car has less power on a really, really hot day vs a really cold day? Same thing, just done to an extreme...