I went with the same diameter as the tb. Is that four inch? And why can't I remember? I did the work, hmm amazing.

 

thinkin it's 3in. that's what i have now and it's the same dia. as the throttle body. got all the stuff for the 4in. so we'll see if there is any noticeable difference.

 

Has anyone done research on comparisons of verious CAIs, predominantly home brews? For example, I know dryer vent hose or the stock corrugated hose creates a lot of turbulence in the hose and messes with the flow. PVC is smoother so should be marked improvement. However, curious if PVC flows significantly different/slower than aftermarket metal versions. PVC is smooth-ish but magnified its actually not uber-smooth. I guess the comparison question to answer is whether or not the added flow of an aftermarket CAI is worth the cost difference compared to the home brew PVC.

I did the PVC version on my 03 back on 2004. Just brought home a new-to-me 2008 so have to do it over again.

 

Well most or I think pretty much all aftermarket versions are 3" dia for the most part. So do a home fab and gain a inch and the smoothness on the inside should really not matter. Just a guess, but the stuff I bought is pretty smooth inside, the only true restrictions are any joint lips on the inside. I am no expert on this, and nor do I have any instruments to test the differences. But what you really gain from a CIA is very small as far a HP goes. So if you want to spend a lot of jack on a aftermarket one that is your choice, but a home brew will give you the same sound and some performance as well.

 

Now I am curious if anyone has done 4" steel dryer vent? Not the flex hose but the rigid tubing. It's much lighter than PVC. Although couplings might be less plug and play.

A couple questions:

1. 4" to 4" OD reducer. Is this PVC? Lowe's guy looked at me like I had a d$%k growing out of my forehead. Filter won't slide directly onto straight PVC? I guess I'll have to try Tractor Supply or alternate location with more PVC selection.

2. Did everyone use plumbing PVC? I was shopping for parts and found the drain PVC is much lighter so will likely buy that instead.

3. Looking for lots of feedback, with pics hopefully, of how everyone supported their intakes. What kind of brackets did you use or build? Did you use just one or multiple?

Thanks.

 

The 3" to 4" reducer is a rubber coupler that clamps on the tb (3") and onto the first 90 (4") the other end has a 4" to 3" PVC hard fitting to clamp the filter onto. I used schedule 40, figuring the thicker the plastic was the more it would insulate from the heat of the motor.

I had an aluminum one on my old durango and that sucker would get hot!

 

The 3" - 4" reducer I was clear on. It was the 4" - 4" OD reducer said to be required for the filter mount that I was unsure of.

 

Great job guys...I love to see the brain at work.

I would like to see a PVC mod that makes use of the fatory box and adds RAM AIR.

I believe I'm just the madman to do that. I'll get right on that...tonight.

Look for a fresh thread on this mod.

 

I did a variation of that idea with my 03. Pictures used to be here in the forum but apparently things get deleted after a few years of inactivity. It was similar to attached pic. I swapped the resonator and the rubber flex hose for 3" PVC to the stock airbox. I pulled the front funnel and used K&N drop in filter.

Although what you are suggesting might not be a bad idea either. The box is already setup to be mounted securely and have some protection from engine side air. All you'd need to do would be to cut out the front section and run intake tubing through the existing side hole.

Any idea which would pull more air? Using a cone filter mod as opposed to using say a K&N drop in filter and a setup like the pic here with the front of the airbox cut out.

From my Harley experience, just about any aftermarket setup is going to pull more air over stock. There are slight differences in specs by brand but they are all pretty close.

I'm thinking I may do my 08 the same as my 03 except I'll cut more of the front of the box open.

 

Well, the mock up is in. Have to wait for pics until the significant other returns with camera. Pretty simple setup, replace the stock flex tube and resonator but keep the stock airbox.

Used 3" PVC cut 9.5" +/-, 3" 90 degree street elbow, two 4" rubber couplers, and 65113 grommet from "Help" section of parts store. Already had PVC glue and high temp red 650 (sensor safe) RTV on hand.

Assembly is really Barney.

Next piece of the puzzle is to enlarge the opening in the front of the airbox. I had already removed the funnel piece and never plan to put it back so no harm in cutting up the stock airbox. Last task is to find a decent drop-in filter that flows a little more than stock paper.

Still interested to see what pjordan4477 comes up with using the stock box for a ram air mod.