I've used them forever and I used to work part time on weekends at a performance shop for a little extra cash when they got busy.

Have seen quite a few dyno'd so I know exactly what a CAI will do and this is my take:

A TRUE CAI - like a Vararam which takes it's air from outside the vehicle gives the best gains BUT is risky since it can take it water. I won't use one because it gets it's air from between the upper and lower bumper and I'm in mud/water that deep at times. I've seen gains of 15-18 RWHP from one by itself but don't expect to see better MPGs, cooler air is more dense and requires more fuel to be dumped into it.

Common CAIs like the K&N, etc. get their air from the engine bay and it's warmer, so gains are less although MPGs will be a tad better than a true CAI because hot air requires less fuel to be mixed with it. Gains from one alone are usually about 5-8 RWHP and I attribute most of this simply to the increased surface area of the cone filter.

NOW where a CAI shines is when you have other mods that make use of the increased intake air. Ported throttle bodies, heads, headers and even some cat-backs show better gains when aided by a CAI than when installed on an engine with a stock intake system.

So basically, if you want to see REAL gains from a CAI, then it requires a re-working of the entire intake/exhaust system...

 

I thought cleaning your filter was common sense? Anyways there are dry filters that dont require oil, i have a aem dryflow on my dakota

 

Back when I had the opportunity to see dyno runs on a pretty regular basis, dry filters couldn't flow near what the oiled ones could BUT there has been a lot of newer technology in dry flow filters over the past 10 years. Now, the better ones flow just as well as the oiled ones but filter like a paper filter.

If I had to buy one today, I'd put a premium dry flow in. Plus maintenance is a lot easier...

 

I don't understand the need with the huge filter the OEM box has. I was kinda surprised how big it was. Anyway to each his own, a lot of wasted money for a cool sound with minimal if any benefit. I had the kn system on my Durango...lost mileage so off it went. That was no cheap piece of equipment good thing I had a guy in Quebec that bought everything I didn't like so that was the only good part about that.

 

I've built a good two dozen now out of sh*t pipe for people, quite a few members on DF. Difference between a home made one and a store bought is minimal unless you are talking the type like a Vararam. Cost of the ones I've made run under $25 plus the cost of the filter which can be as low as $20 or as high as about $50 depending on brand.

I think in the case of the Rams, the big thing is getting rid of the restriction at the "Hemi Hat" baffle in front of the throttle body. I'm betting the stock box, stock filter would give close to the same modest gains if you simply ditched the baffle and straight piped to the filter box. Again, a CAI really doesn't do much unless it's backed up by other mods. I've seen documentation with some headers,after-market heads that have stated "for maximum gains, a CAI should also be installed". I can't remember which brand it was, but we installed a cam once and the docs stated a CAI (and headers) were mandatory for proper performance...

 

Hammer, out of curiosity, of the Hp gains you saw on the dynos, where on the RPM band where they? the dynos I've seen are of gains pretty high up on the band. On the other hand, the dynos are done with the vehicle standing still, so if one is going fast on the road on a cool day I can see some additional gains.

 

I had a bunch of them saved on my old laptop, all kinds of configurations and vehicles. I had one of an SRT Grand Cherokee, naturally aspirated that was over 600 HP! I had pics of the engine that went in it sitting on the hoist right outside of the vehicle - impressive! But I lost the HDD on that laptop. Shame too, I had a bunch of good hunting and fishing pics I didn't have backed up either. So I can't give any specific numbers, but yeah, I wanna say gains started up around 3000 RPM if I remember right...

 

I agree with you, the dynos Ive seen are small increases on the high end, but losses on the low end.

and to the guy who said cleaning a filter is common sense, yea it is, however not after 1 year. just like I thought common sense would say having your filter right on top of your engine is a bad idea. you should look into moving the filter forwards.

but after plenty of driving, the truck is running better, and I'm definitely doing better on the highway, mpgs were 17-19.

and yea the only way your getting a true cold air intake is when the filter is out of the engine bag. my afe on my 3rd gen put the filter down by the bumper, however your risking some serious water lock.

the only ones Ive ever seen really make a difference are the ones on old muscle cars. gets rid of the filter ontop of the carb dead center of all the engine heat and relocates it usually next to the radiator

however I am still never going to understand chrome piping.

 

Oh i drilled a 4'' hole in the bottom of my k&n and ran a tube to my bottom bumper with a scoop so now it gets the air from outside makes 1 hell of a difference

 

I got sick of my CAI and installed a round 14"x3". I am happier with the sound and it feels much more responsive. Then again my truck needs a set of gears...