The parts you'll need:
4" diameter thin-walled (1/8" wall thickness) PVC pipe ($7.99 for 10 ft. section)
1 - 4" thin-walled 90° PVC long sweep elbow ($3.99)
1 - 4" thin-walled 90° PVC street elbow ($4.29)
1 - No. 4 hub connector/coupler ($6.29)
1 - 4" diameter x 4" long speaker port (this part serves as the air horn) ($1.70 plus $7.00 for shipping)
1 - hose clamp (4.25-4.5" diameter hose clamp) ($1.49 estimated price)
1 – 0.75" wide x 1/8" thick x 10" (approx.) long aluminum stock (this is for the mounting bracket) ($3.29 estimated price for 3" section)
PVC cement ($2.99)
black paint (flat or satin) ($3.99 estimated price)
So the cost is around $40 for all the materials. The hardest thing to find was the thin walled PVC piping to attach to the bottom of the air box. Do it best, Lowes, and Home depot didn't have it in my area. I had to go to a special plumbing store to purchase a 10ft stock. Good thing its cheap.
Pics will be shown below.
I was looking for a CAI for my type R motor. I used to own an AEM Hybrid CAI but I ended up selling it to my neighbor. I honestly didn't like the way the car responded with this intake. The car felt "laggy." I didn't feel any increase of power vs. my AEM 2.5" short ram until 6-6500 RPMs. And the power increase wasn't much at all. I didn't dyno the car so I can't say for sure if there was an increase of power with the AEM hybrid CAI but my butt dyno is pretty damn accurate lol. And my butt dyno told me that the increase in power wasn't enough to justify the big price tag if I were to get another CAI.
So my search for another CAI started on ebay. I found CAI's made for Integra LS/RS as well as 92-95 Civic's. I needed something that had a 3" diameter piping. To make a long story short, here's a thread I started a few days ago.
I decided to make my own CAI with my Type R intake box. I wanted to make it similar to a comptech icebox as well as a mugen intake box. The Mugen intake box uses 4" diameter piping for the cold air extension, which the comptech box uses 3" piping.
The install wasn't too bad, but it wasn't easy. Most of the time spent was trying to get the intake's cold air extension placed perfectly as well as figuring out a way where the intake box won't hit the hood of the car.
First thing you have to do is cut the thin walled PVC pipe to 7 in. Attach it to the bottom of the intake box with the coupler (it has a worm band around it). Then attach the other two PVC pipes/elbows and have it look similar to this:
Do a test fit and make sure the bottom extension faces the way you want it to. I used the PVC cement to join the bottom two cold air extensions together. Only do this when you're ready to finalize your installation. Also, I had to notch my clutch line bracket to make sure the intake sat down correctly in the engine bay. In addition, I had to install the intake box bracket to the "bottom" of the shock tower bracket. Its hard to explain but the pics are shown below. I had to do this to make sure the intake box sat down as far as it could so the hood would clear. I haven't installed the air horn yet, because it hasn't been shipped, but once I get it in, I'll install it and take pics.
As for performance...I highly recommend this setup. Not only does it look stock which I like, but I feel the throttle response is A LOT better compared to the AEM CAI as well as more power throughout the RPM range. You will definitely feel a difference in torque in the midrange which I felt right away. Again, this is with my highly accurate butt dyno so take it for what its worth. I will dyno this setup vs. the AEM CAI, but it'll be a while before I do this. I want to upgrade a few more things first (header and exhaust) before I bring the car in to get it dyno'd.
For the price in parts, its a worthwhile upgrade if you have a spare airbox. I would consider making a "kit" if there's any interest. I would have to charge at least $60-70.00 considering the time making the kit as well as sourcing the parts, and even then, it might not be worth it to me. Anyhow, here's the pics: