Custom CAI mod!

mikeb33

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I looked at my stock air filter assembly and saw room for improvement. For starters, the 2 oval shaped ports on the side of the air box that connect to the inner fender are only about 15 square inches combined. The stock air filter element is over 100 square inches. While it seems like a good way of assuring fresh air only, the volume just isn't there.
Most aftermarkets units solve this by having a giant cone filter and the end of the tube. Crude, but effective. And while they are commonly call CAI(cold air induction), most seem to be open the engine compartment or have a heat shield, but I think most of the HP gains are dues to all the extra available air, not cold air. The Volant is the exception to this and in the only one I really considered before starting my project.
What I did is cut a 3.5" hole in the bottom of the airbox and the steel tray below it, and then connected a duct tube to hang down behind the bumper. A 3" hole has about 7 square inches to add to the stock 15.

I started by taking the stock system off:
 

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mikeb33

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The metal tray that lives under the airbox.
 

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mikeb33

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Tray removed. You clearly see there is nothing below down to the ground.
 

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mikeb33

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Here is my Home Depot PVC adapter and aluminum flex duct. the threads on the adapter screw onto the duct very well, no other securing needed.
 

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mikeb33

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I'm sorry I missed taking a picture, but I cut a hole in the bottom of the airbox from the bottom as far forward as possible, without cutting into the sides. Then I put the plastic housing back in place and marked where to continue the hole in the plate. I then cut the 3.5" hole in the plate and done properly, the one hole is directly above the other.
The hole is such a perfect size, that that the pvc adaptor can be pressed in with a little effort.
I put the duct into the adapter and and then into the plate and then bolted the plate back in it's home. I then put the airbox back where it belongs.
 

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mikeb33

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I put it all back together using an Airaid intake tube. After I bought it I determined it isn't much bigger than stock and does have a flat side underneath. I do like that is isn't so outrageous looking like the stock one.
I also put a K&N panel filter in too.

The test drive proves my theory. The extra air is really welcomed over 3K RPM. It also sounds like stock unless I pressed more than half throttle. You can easily drive all day and hear nothing now, or lay on the pedal and VOOOM!
There seems to be more power for sure. I wish I had a dyno(beside my butt) to measure the gains.
 

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mikeb33

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Update:
I put the stock intake tube back on. Holding it side by side with the Airaid piece it seems to have just as much flow capability. The Airaid one isn't any bigger or have any advantage besides looking better and making more noise. It was very loud over half or more throttle. It is amazing how the stock one with the extra chambers really quiets it down.
It still seems to have more power than stock due to my intake tube modification.
 

Mark

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Where does the bottom of the tubing go?

Pics?

Does it just hang there dangling?
 

mikeb33

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Where does the bottom of the tubing go?

Pics?

Does it just hang there dangling?

Yeah it just hangs there. The aluminum tube is very light and it screwed into the plastic adapter very securely. I don't think it is going anywhere.
 

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pwrjnky

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looks like a great mod and I'm considering doing it. Only thing that I may do is to possibly add a screen where the pvc and tube meet or at the end of it to keep a lot of the extra debris from clogging up the air filter even faster. It looks like that tube will be sucking in all kinds of stuff. Great work though.
 

mikeb33

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I'm not sure if there is enough suction to pull anything substantial up, but who knows. I am not sure the tube really does anything, the area right below the airbox and plate is wide open to the outside air.
 

treepete

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I like it. I think it will be a nice way to suck up some cold air. I agree with a small screen to keep out little floaty seeds and light debris, etc.
 

Yuke2K

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I've been thinking of doing this for a while, so thanks for the guide!

I've got a bit of experience making intakes for my cars...I made one for my Grand Prix a couple years ago, and it turned out really well. I'll probably do the same thing you did for my Yukon, but I'll more than likely try to figure out a way to do it with black 3" or 4" ABS tubing instead of dryer duct.

I'll post pics when I get around to getting it done.
 

LowStro9

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Don;t flame me for giving direction on my second post but keep in mind that you have increased the volume bit the airflow is substantially more turbulent than that of the sought after smooth sided CAI. You def want to screen that in some fashion or another. The intake vac pressure on any car is a heck of a lot more than you would think. It can easily suck a leaf or plastic trash up in with little to no effort; specially at WOT. I spend a decent amount of time on track with my Porsche and intake is always an issue.
 

Yuke2K

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You do realize that he's not running an open tube to an open box, right? There is a K&N panel filter in the airbox still. Leaves and debris aren't as worrisome as water in his case, since they'd at least be trapped by the filter.
 

mikeb33

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The factory airbox openings are still there so the pickup tube does not get enough vacuum to pick up stuff. At least there is no debris in there yet.
 

Volant1

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We make a part just like this, but I have a ton of people call and tell me they have done this. The only thing I would suggest is bring it up behind the tow hook, that way it sits behind the front valance and cuts up 90 degrees, this will cut down on the amount of water you see in the box
 

03undercover

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anyone make a non baffled tube from the air box to the throttle body ???

I hate the silincer and im sure its restrictive
 
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