Custom CAI

So I am thinking about making a custom CAI. I saw somebody on here had a pretty sweet little job with some aluminum tubing, and a cone filter, but I was thinking about trying to take that a step further...

I have an opening under each of my headlights that is relatively large, say 8in by 3 in tall. I was thinking I could run a y-pipe directly off the TB of my truck and send a 3-3.5" pipe in each direction off the top of my block. If I get particularly motivated, or stuck, I would consider moving the battery to where the airbox currently resides.

I could custom fit a box for each side (thin tin, rivets, and some silicone sealant) with the filter inside, and then run a similarly made "ram" under each of my headlights. I haven't really put much thought into this I am just kind of tossing ideas around ATM.

The thing I am most unsure of is what to use for tubing. I want something relatively solid, like pvc, that insulates against heat a little (which is why I don't particularly want aluminum), but that I could fit into the shape I need. I was thinking some type of heat shape vinyl would be good, but in 3in+ form it would be pretty expensive.

I was thinking I could do this project for $150, and have a pretty sweet intake that would MAYBE build 1psi, or even 2... but would certainly not limit flow at all. Also, it would look pretty BA with two filters, and a ram on each side lol.

Thoughts? Call me a *******? Tell me to just buy an aftermarket CAI? lol

certainly not *******, but motivated yes

you are right with shiny metal tubing, its eat catching.
alu is great heat conductor, stainless a little less.
even more, a round section is not so good for laminated air flux, oval helps.

you can look at the Volant web site, it can give you ideas... there are closed boxes and different kind of scoops.

again, for your boxes, i would not use metal, its a heat friend
or, if you can, double wall with air or glass whool or smt like this to insulate...

plz post pics if you do smt!

Damn that sounds like you got it all planned out. I made a little home made CAI, nothing fancy, out of pvc and it works fine. Definitely post pics if you do this, sounds awesome

sounds like a sweet idea to me

TexasRammer said:

Damn that sounds like you got it all planned out. I made a little home made CAI, nothing fancy, out of pvc and it works fine. Definitely post pics if you do this, sounds awesome

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Do you have pictures of this posted somewhere?

derrickwmartin said:

Do you have pictures of this posted somewhere?

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http://www.ramforum.com/f50/my-homemade-cai-17143/

So my question is what's the best way to tie in your O2 sensor, now y'all got me
Thinking about doing my own CAI

That PVC came out looking awesome, I was a little worried PVC wouldn't have a "finished" look you know, but that looks really good once you painted it. What size did you use? My guess based on memory was the TB is about 5" OD, so I would run two 4" tubes?

I am in Australia right now, and am trying to get this job kind of planned out for when I get back to the states so all the little info is really helpful, so were the pictures lol.

I think for the MAS you could just drill a hole in the PVC, and put some kind of a PVC nipple on it that the stock sensor could fit into. I think there are jsut a couple screws holding the sensor in place on the stock tubing (correct me if I am wrong on this one), so you could just use come PVC cement to set some nuts to you custom nipple and off you go.

jlb said:

That PVC came out looking awesome, I was a little worried PVC wouldn't have a "finished" look you know, but that looks really good once you painted it. What size did you use? My guess based on memory was the TB is about 5" OD, so I would run two 4" tubes?

I am in Australia right now, and am trying to get this job kind of planned out for when I get back to the states so all the little info is really helpful, so were the pictures lol.

I think for the MAS you could just drill a hole in the PVC, and put some kind of a PVC nipple on it that the stock sensor could fit into. I think there are jsut a couple screws holding the sensor in place on the stock tubing (correct me if I am wrong on this one), so you could just use come PVC cement to set some nuts to you custom nipple and off you go.

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Thanks, I was kinda worried too but I wasnt all that concerned because this isnt the prettiest truck lol. My paint job was a little crappy, but it definitely helps make it look neater. I used 3 inch pipe, but I have no idea what the throttle body is for the 4th gen hemis. I would think it would be around the same... maybe someone with a 4th gen will know

Naw, your probably right, I would imagine it would be the same size. I have never pulled the intake runner, and I haven't seen my truck for 2 months now, so I am just going on a rough memory of it.

jlb said:

and have a pretty sweet intake that would MAYBE build 1psi, or even 2... but would certainly not limit flow at all. Also, it would look pretty BA with two filters, and a ram on each side lol.

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Building pressure is pretty much not going to happen. You won't even overcome intake vacuum at WOT at 80 MPH. Ram Air is a joke. Neat in concept, little more.

Feel free to argue, everyone always does. If you had velocity stacks on each cylinder and could somehow achieve laminar flow into each one from the grill (really hard to do through an intake / throttle body) you might get SOME benefit, oh yea, and you'd have to be speeding everywhere at WOT to see it.

Intakes sound cool, damned cool on a Hemi I might add. But that's about it.

Well I want to see this cause I might be asking for the build specs so I can put my twist on it

I think it would be interesting to see how a homemade intake dynos against one of the manufactured ones.

Well i think im the one the o/p is talking about in first post and i can say this the tube injecting air does make a difference not like omfg kind but much better throttle response and as far as the aluminum tube it does not get hot at all.

I have to argue against (for?) using metal tubing for the intake
I rolled a piece of steel and color matched it to replace the torque tube on my girlfriends cummins.
With this tube being right next to the exhaust manifold just above the turbo, I was not only worried about the air absorbing the heat but also the paint melting on the inside and outside of the tube
After I first installed it I measured the temperature of the tube after a two hour drive with an IR thermometer, I can't remember exactly what the temperature of the tube was but it was within 10-20* of the ambient temperature

After 3,000 miles in the past 3-4 months since I put it on there are still no signs of heat discoloration on the tube

For as much performance gain as you really get with CAI, on a diesel or gas job, the difference in air temperature of metal vs. plastic is insignificant iMO
It will be replaced by a full intake once her and I are done with school but for now it sounds awesome, she seems to have picked up .5mpg, it sounds awesome lol and the whole thing cost me less then $70

WhiteExpress said:

Building pressure is pretty much not going to happen. You won't even overcome intake vacuum at WOT at 80 MPH. Ram Air is a joke. Neat in concept, little more.

Feel free to argue, everyone always does. If you had velocity stacks on each cylinder and could somehow achieve laminar flow into each one from the grill (really hard to do through an intake / throttle body) you might get SOME benefit, oh yea, and you'd have to be speeding everywhere at WOT to see it.

Intakes sound cool, damned cool on a Hemi I might add. But that's about it.

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I think you are quite wrong in you assesment that intakes only offer a cool sound on a hemi... I am pretty sure alot of members on here, backed up by dyno runs would argue that they do in fact offer a performance gain as well.

I will agree with you on your point that the flow of air into the throttle body will not be laminar (its Reynold's number will in fact be a bit over 20,000), but I don't think any of the systems involving fluid flow on your truck are. Obviously exhaust is out of the question, coolant I would be highly skeptical of (with the obvious exception of being in the radiator itself), and at best, fuel flow is probably laminar in the main line headed towards your motor...

You certainly can't make the arguement that a turbo, or supercharger creates laminar flow at the TB unless you have a ridiculously large hydraulic diameter for all of your tubing (which would be inefficient space wise).

As you could see in the original post I introduced to topic of pressure with not only maybe, but MAYBE, because I didn't want the focus of this thread to be based on opinions about how infeasible it is to generate pressure with ram air.

In response though the volume of air the the hemi draws at 4500 RPM is in fact half of the volume that would pass through the largest area of my rams at 60 MPH. Obviously this is not a perfect world so losses due to flow characteristics are to be expected, but probably not on that scale.

While it is true that I probably won't generate any positive relative pressure at the throttle body, I would be happy to bet vast sums of money that the relative pressure at the TB will be higher with the ram system in place, and at 60 MPH than it would be without it there. This means that because of the rams my Hemi would be breathing better, thus generating more power.

Your Witness. jk lol

On a note about the Aluminum tubing, I guess I hadn't thought about the temperature thing, but the airflow through it is great enough that there really wouldn't be too much waste heat exchange into the air passing by...

How do you go about making corners in the stuff (buy elbows?)? Also, how does its price compare to PVC? What is a good place to find it too?

I made my own CAI, but it looks ghetto. u can save 100$ making ur own but its worth it to buy one because they look PRO. I can post pics tomorrow if u want to see what a shantty job looks like. I DONT recommend that you make your own even tho it is 100$ functional

Lawhand said:

I made my own CAI, but it looks ghetto. u can save 100$ making ur own but its worth it to buy one because they look PRO. I can post pics tomorrow if u want to see what a shantty job looks like. I DONT recommend that you make your own even tho it is 100$ functional

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PICS!!! I made my own too, but I want to see one on a newer truck

Yeah I wanna see it too