I have finally found the right combo to build your own CAI. Tube diameter is biggest problem that I had. Choose the wrong diameter - get the service engine light. So here's the Recipe:

2.5" PVC pipe

Thats it. The ID of the tubing gives the right air velocity for the MAF to work properly. 2" PVC is too small and restrictive, 3" is too big and doesn't give enough air velocity. I also tried several diameters of aluminum tubing. 2.5" is not a standard size. You will probably have to go to a sprinkler system supply store to find it.

I have made one similar to the AirRaid (~8" long tube) and one similar to the CGS (same path with 2 PVC elbows). Both worked with NO check-engine light. I've been running it for over a month now and no problems. WoooHooooo!

I know it is not precisely tuned like the CGS, but you can feel a difference from the seat-of-the-pants guage. Better MPG by about 1.5 - using the old math, and the DIC.

The only hard part is the adapter for the MAF sensor. I designed one in 3D CAD and had it made by a rapid prototyping house from plastic. I'd be glad to share the drawing if anyone is interested.

And as always, if you prefer professional performance parts, buy one of the others. But if you are budget minded and have a little building ability, this one is pretty simple.

Good Luck! :thumb:

I'll beat everyone to it...
PIC's PLEASE!!! (of both units -preferabbly installed!)
Thanks for sharing...:thumb:

congrats big time
nothing wrong w some Texas Ingenuity

I'll beat everyone to it...
PIC's PLEASE!!! (of both units -preferabbly installed!)
Thanks for sharing...:thumb:

DITTO!!!

What Ng said...............

http://www.hhrclub.org/smilies/lg/lg0350.gifI'd like to see what it looks like!

Pics please, I would like to do the same for mine, mainly for the increased gas mileage.

I knew that was coming. :lol:

I'll try to get some pics in the next few days and post both setups.

pic's please too

OK. Here is the first set of pictures:

Front
http://www.chevyhhr.net/gallery/files/1/9/1/SRAM_front.jpg

Right
http://www.chevyhhr.net/gallery/files/1/9/1/SRAM_right.jpg

Left
http://www.chevyhhr.net/gallery/files/1/9/1/SRAM_left.jpg

There are no braces or brackets holding the air filter in place. I do have a couple of heat resistant plastic grommets that fit over 2 of the pleats in the filter like a clip to keep the filter element from rubbing on the engine.

Now I am sure that some will say that this looks like it is going to draw in a lot of hot air since there is no heat shield. Yes that is true while sitting still at a stop light, however, I have made a small mod around the radiator to help increase air flow. I have removed the plastic guard from the right and left side of the radiator. I have also trimmed the vertical wall off of the plastic cover on top of the radiator. (See the arrows in the pic below) This allows cold air to flow through the grill (even in the summer heat, 100° air is cold compared to the engine temp) - then through the engine compartment - then the hot air flows out the rear of the engine compartment where the hood meets the windshield. It is very similar to how heat escapes with a cowl induction hood.

Radiator Plastic Detail
http://www.chevyhhr.net/gallery/files/1/9/1/rad_plastic.jpg

I don't have the CGS style home-made intake on my car right now. However here are the drawings for it. If I get a chance to swap and take a picture this weekend, I will.

CAI Assembly View
You may have to change the length of Tube #2. I can't remember if this is the version that puts the filter on top, or down in the hole just like the CGS. If anyone has a CGS and would like to measure the actual distance for where I show 10.75 inches, then I'll update the print.
http://www.chevyhhr.net/gallery/files/1/9/1/cai_asm_drw_1.jpg

CAI Tube Details
Dimensions for the tube details. The stepped diameter on Tube #1 is not necessary. It just makes it a little easier to fit on the stock rubber elbow. I did not add the step, but it is pretty hard to get the rubber elbow over the tube. I had to use the 2 screwdriver trick like you do when trying to put a tire bead over a rim. I don't think it is stretched so much that the rubber will split over time though. It should be safe.
http://www.chevyhhr.net/gallery/files/1/9/1/cai_asm_drw_2.jpg

MAF Sensor Adapter
These are te basic dimensions that you need to create a Mass Air Flow Sensor adapter for use with 2.5" PVC tubing. If you try it with other tubing, Just make sure the ø2.875 matches your tubes actual outside diameter. I made a gasket out of bicycle inner tube to put between the adapter and the PVC tube.
http://www.chevyhhr.net/gallery/files/1/9/1/maf_adapter.jpg

That's it.

BTW, Sorry for the not-so-clear images. The only camera I have right now is a 640x480 Batman Kids camera. But at least you can tell what I've got now.

Interesting...You may want to paint the PVC pipe black with some high temp paint so it blends in...

Ng

I actually plan to paint the tube and adapter blue to match the body. Looking for a Blue filter like CJ's too.

Got to take it to a shop, you know how they are gonna want to see "DYNO" results! :thumb:

I know. But I am not going to. A DYNO run would cost me more than what I spent to build the intake. Even if it has the exact same power/torque as stock, I choose it over the stock box. It is just so much cleaner looking than the giant plastic box.

This allows cold air to flow through the grill ... then the hot air flows out the rear of the engine compartment where the hood meets the windshield.

Correction. By looking at my own pictures, I realized the air had nowhere to escape out the rear of the engine compartment. There is a piece of rubber weather stipping that runs along the back that seals when the hood closes. You have to remove that weather strippng to allow the hot air to escape over the windshield.

Watch your engine temps now. The covers you removed on the sides of the radiator were placed there to cause the electric fan to "draw" more air through the radiator core.
By removing these panels you have actually reduced the amount of cooling air that travels through the rad core.

It's not a good idea to tamper with this (removing air dam panels & weatherstripping) - especially on newer computer-controlled engines.
Engineers spend weeks studying the effects of air flow patterns through an engine compartment.
I've seen a slew of guys do things like this and get worse performance than stock.

Not trying to shoot down your ingenuity :thumb: - just a tip,

Thanks for the heads up. :thumb: I did think of that though. I have had it like this for over a month now in 110° temps here in TX with no problems. I have kept an eye on the engine temp and it is staying right where it should. Anyway, it works for me, but everyone should keep that in mind with any mods they do...
:steering:

That's the main reson I put it out there...so that newcomers might consider the ramifications of any mods before changing something.

Enjoy! :thumb:

This wont work for me, the car just shuts off after about 3 seconds after starting.

I love the effort and idea. Keep it up. Now if I just had time to make something for the SS.........too many projects going on right now.

FYI- heat does not 'escape' from the engine compartment in a cowl induction hood setup. The word 'induction' alone should make that clear.

In a cowl induction setup, the high pressure area at the base of the windshield is used to draw cool air into the carburetor. (using the 69 Camaro Z28 as an example) This is why the cowl induction hoods are sealed to a plate that surrounds the carb.
http://static.howstuffworks.com/gif/69z28_03.jpg
http://musclecars.howstuffworks.com/classic-muscle-cars/1969-chevy-camaro-z28.htm

Glad to see I am not the only one who would rather build a CAI than pay good money for one. I'm really cheap I used mostly stock parts.

Thanks Mongo, well said!:thumb: