So I finally got my ram cold air intake all assembled on my Cummins. My design is "new", however, I borrowed heavily from two projects I saw over at Cumminsforum (AH64ID & turborep):
Home Deopt CAI on a 3rd Gen - Dodge Cummins Diesel Forum
How To Fab a Cold Air Intake from the Fog Lamp Hole - Dodge Cummins Diesel Forum
I liked AH64ID's modification of the stock air box with the toilet flange for an inexpensive, DIY cold air intake. I also liked turborep's idea of using the fog lamp hole to get some ram air. What I didn't like about turborep's setup, however, is that it made the fog lamp hole look very non-stock from the outside. I wasn't too crazy about the light dryer vent hose either.
I came up with the idea of using a roofing flange "boot" behind the existing fog lamp hole. These boots are the palstic rubber ones used in construction for when you send a pipe out the roof. It seals between the pipe with rubber and than has a plastic flange that fits underneath the shingles.
So, first off I took off the bumper to make it easier to work on. I suppose it might be possible to do it with the bumper still on the truck, but it's fairly easy to remove and it makes things a whiole lot easier to work on. I had to cut down the platic flange on the boot to get a good flat contact surface all the way around the hole. I then used RTV silicone to seal it against the bumper. Here's a view from the back side of the bumper:
and from the front side with the stock fog lamp hole grill off:
and with the grile back in place:
I did have to shave a little bit of plastic off the back of the grille to prevent it from contacting the boot, however, what I like is that it keeps thing looking pretty much stock.
Inside the airbox, mine looks pretty much just like AH64ID's does:
And here's the 3" PVC "downpipe" that connects the toilet flange to the boot:
I used two 45 deg elbows rather than one 90 deg elbow--that made it much easier to line the angles and offsets up properly. I also removed the stock plastic piece that hangs down in the way. turborep chose to saw a hole in it, but I chose to just take it out. If I ever want to go back to stock it doesn't have a hole sawed in it.
And here's the finished view from the outside:
I may end up getting some black PVC-compatible paint to spray the pipe so it's a little less conspicuous. It's really only visible now if you squat down and look directly through the fog lamp hole grille. Of course, I probably should have just gotten some black PVC pipe, but white is what I had lying around.