Custom Cold Air Intake - with pics

A few guys were asking about this on the old forum and I did promise I'd put some pics up so here they are. Most guys will tell you that running pods will lose HP, which is true if you are sucking in hot air. This is my set up, it works really well on my sled. It is very easy to dissassemble and remove, basically two hose clamps. The aluminum intake tubing I used was 2 3/4" from Vibrant (http://vibrantperformance.com/catal..._1036&osCsid=d5878085cac3c0f7b31f849a5547fe9e) same as the turbo guys use. It fits 40 mm carbs perfect. I did have to trim the tubes a bit to make them fit where I wanted to but all in all it probably only took 1-2 hrs to build the system (measuring, cutting, testfitting, etc).

The parts cost about $90, not including the filters. Weight is slightly less than the stock airbox, maybe 0.5 -1 lb, but the main advantage is the cold air feeding the motor.

I use 10 degree angled Uni filters with a pre-filter sock (not shown in pics). I used the angled pods so that they fit under the headlight area, you can get straighter ones. I kept the upper tube as long as possible to keep the filters up in the cold air flow as best as possible, but they could be cut down if height was an issue. There are other ways to create different cold air induction points, I mounted mine in the headlight area because I wanted a bit of an "air scoop" effect (which really only happens at higher speeds on the trail or going downhill really fast ). Mainly I just wanted to maximize the cold air flow into the motor. I don't ride at night much so not having a headlight isn't a big deal for me. The intake could be angled backward behind the headlight, sideways, through the hood or anywhere you wanted really. Its just a matter of getting the right pieces and cutting them to length.

The drawbacks to the system are that you do not have a headlight, so riding at night is a little sketchy unless you use an alternate source of light. With no screens, more snow does tend to accumulate in the engine area. Keep in mind that I use this competely open system in spring riding, for deep powder snow I cover the holes with screen. You will likely need to play with jetting if you go with an open system such as this.

First pic is where they are mounted in the headlight area
Second pic is how they look under the hood
Third pic is a side view of the intake tube with carb

BugIto said:

You need a screen on the light opening to keep snow/ice buildup off of your filters.

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I do use a screen on the opening and pre-filters. They keep a ton of the snow off. I also have them lubed with Bell filter lube, which is basically an oil. It makes them kinda sticky, I wouldn't recommend it. I'm going to something different this year, but regardless, it works. Water will not penetrate your filter, it is basically a water repellant. Never wrung a drop of water out of them last year.

BugIto said:

I wonder how well the cold air will be "sucked" in and down that tube. Your setup looks similar to most car cold air intakes. Except that they are not pulling air from the top down, but more evenly with the intake (usually from the bumper area).

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Because the filter is directly in the cold air flow, it works well. Had a similar set up on my old sled. Doesn't do as much at slow speeds as it does when you are moving faster, however you aren't sucking hot air in from directly at the motor, which is the main benefit. Going down the trail when it is cold, this type of system really shines. You're right, it is very similar to a car set up, it is built from auto fabrication parts essentially. Drawing air in from along the bumper would cause huge snow build up on the filter (since in deep snow you would be basically plowing through with your filter), the only real way on a sled to make it work is keep it up high. Too low and you hit it against branches, its closer to the snow, etc. There is a bit of a trade off, IMO the benefits outweighed the drawbacks in my case.

mattymac said:

Looks like if you hit a bump with all the weight on that rubber boot, it would bounce around a ton or fall off completely?

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LOL Matt, good eyes!! The boots nomally have two hose clamps on them, one on the carb side and one on the tube side to hold them on. The filters have a clamp on them as well which aren't there in the photos. I took it all off my sled to make a few carb mods and since it is getting close to winter, I thought I should get the pics up so I slapped it on the sled, didn't bother putting all the hose clamps on since the carbs are now back on my shop bench again. You can zip tie them together for stability as well, and tie into other components also. That is one silicone boot that is cut in half too, when you buy the boots from Vibrant, they are twice as long as what you see in the photo. I just got one and cut it in half becuz for clearance purposes I need to keep the carbs closer to the front of the hood opening.

Meatman said:

would a motor have a problem pulling air? would like to get some more info on that set up, looks promising!

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Motor shouldn't have any more problem pulling air than a stock air box. The filters let in more than enough air to supply the motor or you could make some coarser ones out of a different material. Filters are cheap and easy to change out though too so a guy cold try many different types to find one that you like. If a guy was worried about it, you could run K&N's instead. They flow enough air for a 300HP turbo.