I built my own intake using that article and I found everything on jcwhitney.com. If that part # doesn't work anymore, the piping used is actually listed under the 'exhaust piping' category. Just find which diameter you are going to use and the correct mandrel bend (a 180 degree and a 90 degree) in that size. I think the total for my order came out to be around $40.00 shipped. I went to a local Home Depot and they had the PVC pipe clamps that are needed.
I made my own a couple of weeks ago. The piping was 2.5" which was recommended b/c mines an ls. It costs around $40 shipped from JCWhitney. When you go to the site just enter the part number in the parts number search, and it should come right up. It's a great project
Im not sure, it will slow down the velocity of the air, which will result in less horsepower, but i guess it could let in more air. But i read that for LS engines 2.5 is enough. For highly modified engines then use the 3"
Has anyone actually dyno'ed 2.5" vs 3.0"? I have a 3.0" diameter short ram from eBay on my LS and it performs just fine, but I'm curious as to how much different the 2.5" would perform. I'm fairly certain that 3.0" is better for me now, but I'm wondering if 2.5" would have performed better back before my other mods (especially last weekend's project).
Also, I noticed that the DIY CAI says to paint the inside of the pipe. Is that to make it flow better? The inside of mine is unpainted, but I'm wondering about the power difference of the inside being painted vs unpainted.
From my experience using a 3" short ram, it felt like it was choking a little bit when I floored it... If I was crusing down the highway with my foot off of the gas and then I suddenly floored it, it would have a short burst of power but quickly drop off to "normal". I'm thinking that the intake tube would get full of air when I was off the throttle, then when I got on it, it would suck in all that air (the burst of power) but then not have as much air available to it (the sudden drop off). I'm curious as to if the 2.5" intakes do that, but I would suspect not as much, and it might not even affect CAI's. Still curious to hear from people who actually know though.
I solved the problem last weekend... I made a custom PVC contraption and now the short ram's filter is being bombarded with outside air collected from the airdam. The underhood heat dropped significantly and the car accelerates better on the highway. And no more power burst then drop off when I floor it. Here's a link