Cold Air Intake? By gmon (Read 7,653 times)

[jvino]

Creative mod keep us posted how it works. Wow you got a lot of scooters do you plan on doing this mod to all of them?

[jct842]

The more I think about it if the air/fuel mix is right at full throttle when taking off or going up a hill then going down hill at full throttle and the scoop working as claimed will result in a very lean condition.

[gmon]

jvino I only have one scooter.
jct842 I was thinking the same thing and I wanted to compensate with the larger carb jets, but it didn't work. The scooter lost power and speed but sounded nice. I used 3 filters between 3 of the joints. After 5 min of testing and failing, my spark plug went bad and got totally dark. I went back to the original design through the air box and the scooter runs good now.

The fail video:

[gmon]

Here is some pics of the project


The Filter:

From Carb:


Filter again:


Filters on 3 places:

[gmon]

I would probably need fuel injection to work. I think the scooter when is idling is not getting to much air, because of the long intake pipe. But it runs good when I run it through the air box, so I don't know. I ended up with this setup:
[img src="i62.tinypic.com/20h9imf.jpg" src="http://i62.tinypic.com/20h9imf.jpg" style="max-width:100%;"]
Now at top speed and down heal is running lean (have #85 and #38 jets), you can hear the air getting forced and sucked up

[jvino]

Good call I think you are thinking right to much air means to lean. You are taking a chance of blowing your scooter up. Don't get me wrong it is very creative what you came up with. Nice video buy the way I watched it yesterday. Very creative good looks kid.

[jct842]

The best solution and simplest is a uni as close to the carb as you can get it. Easy to clean and gets plenty of cold air from the sides.

[gmon]

jct842 that's right, but I wanted to do Ram air and create pressure at hi speed to force feed the air in the carburetor. My air is colder then a uni filter setup above the engine - the heat rises up.
I don't know why my setup didn't work, but my guess is: 1) The 3 air filters I put prevented the air flow to go smoothly into the carb at idling and low speed, I should have tried with only one filter? or 2)for ram air to work you need a sealed container with volume (air box) to feed the air into.
So the next thing I am going to do is seal the air-box completely with silicon, because right now I am sure that air escapes from it. They are not made air tide

[jct842]

Wrong.... heat rises yes but once you are moving the heat no longer rises but is lost in the air flow. As I said before the best performance going is a uni as close to the carb as you can get it. There are some who have turned the carb forward, and that takes a special manifold so that the carb float is level. Then they put the uni under the seat between their legs right out front in clean air. You are wasting your time with a ram. First of all the longer air has to travel the bigger the duct has to be. It would take some real engineering to design a ram that has the proper air/fuel mix at full throttle at speeds varying between 0 mph and say 50mph. I won't say it can not be done but how will you keep the air/fuel mix right for different speeds? Alley is the expert on carbs, you might ask his advice on a ram and how to keep air/fuel mix the same when air pressure varies/

[gmon]

jct842 Why wrong? I said "My air is colder then a uni filter setup above the engine". Even if you are moving, the ambient temperature is higher there than the front for sure. And when you are not moving, your filter gets heated up and the stuff around your filter also absorbs heat and then radiates it. I only ride my scooter in the city, so its stop and go with few straits. I know "It would take some real engineering to design a ram that has the proper air/fuel mix", but that was not my goal to make it proper. I'm not an engineer, I read few thing about ram and my understanding is that Ram usually is most effective after 50 mph, the length of the pipe relates to what rmp's you will get the most gain (shorter pipe means max gain at higher rpm, longer at lower rpm). The opening of the ram air - the faster you go, the smaller the opening should be for maximum efficiency, going slower -bigger opening... So I wanted to experiment and I did get better results +3 miles top speed and faster acceleration to top speed. What is your gain from the uni filter?

[jct842]

A uni along with a free flow exhaust is basically trouble free gives a decent gain in performance and super easy to service. The gain you saw is more than likely the result of the long intake path changing the fuel/air mix. If you neglect a free flow exhaust no matter what you do will have little gains.

Should you want to get some real fresh air, pick up or manufacture a new manifold to rotate the carb facing forward instead of pointing to the rear as you have it now.

[gmon]

Oil Catch and Release
I had the oil catch kit for a while, so finally I got some time to install it. I read that the oil may foam up, so I decided not to install the part with the fitting in place of the oil cap, instead I just ran the hose to the back mudguard, so it can drip there. The reason I bought it was because I was getting oil inside the air box and my filter was wet at the bottom right corner - soaked with oil.
Pics:

I also installed a computer fan to help cool down the vapors faster(I hope)
Fan Front:

Top View - I put an old fuel filter


...to the rear mud guard

[gmon]

Now, instead of plugging the hole on the air-box hose, I used a pcv valve. The valve only lets air in and not out. Since my engine is running rich at idling (because of the long intake pipe and the up-jetting)) this might help to breath a little better. The valve will also help to keep the pressure when scooping air with the intake, since is not letting air out

[Alleyoop]

You do NOT want that hose from the Valve Cover Vent by your tire. If it squirts OIL out it will get on your tire and you will have a great experience. What you want to do is put a fuel filter on the end of that hose and just zip tie it higher than the Valve cover.
Alleyoop

[gmon]

I actually thought of that might be a problem. I installed the hose all the way to the left and I have 2 inches clearance away from the tire. I shouldn't squirt since it goes first to the oil catch container, gets depressurized and cooled and then just drips down hopefully.  I will still keep an eye on to see where will be dripping