#1) Your car, in stock form, is only able to use so much air, and the stock air box on the 3 is pretty good at giving your motor all the air it needs, and filtering out all the bad stuff out of the air before it reaches your combustion. This is the reason why after market intakes don't give this car a huge increase in power. You could have an air intake the size of the front of your car and it would be the same story.

#2) If you add exhaust, down pipe, program and other mods into the mix, the intake is going to do more for you. You are burning up more fuel, so you can now use more air. Your after market intake will now start helping your car's performance more.

#3) Lets not forget the main reason for an intake. It's to get as much clean air into the engine as it needs. Clean being the key word here. More air doesn't do any good if it's dirty. Cold air is better, but it takes more to draw that cold air into the intake because it has farther to go. Short ram takes in hot air (less Oxygen) but it has an easier time getting there. Now remember, your air goes through an intercooler. CAI make less of a difference on intercooled cars.

Hope this helped.

 

But the after market intakes have a filter too. And they are quite good as well. If you read up on it, they are different then stock filters. Colder air is better. So get a CAI!

 

Everyone sure knows there stuff. I've done some research on my own as well as talked to a guy I work with who is an engineer, and worked on racecars his whole life. He like other people in this thread seem to think CAI would possibly give a slight boost, but at the same time use more fuel because it will make the computer dump more fuel in. I've also found and article saying hot air intake would be better, because the hot air combusts more easily. All in all I now think if I do anything it will probably be a ram air. This is mostly because I would be scared to death of sucking water into my engine. I guess I just want to do something to my car to say I did it. Thats probably the biggest thing.

 

If you want better fuel economy, then hotter air is better (to a point), if you want better top end performance, then colder air is better. Plain and simple.

 

Hot air doesn't make power. Cold air does. Ever notice how your car feels peppier on a cool morning?

SRI vs CAI... you won't notice anything outstanding on the NA 3 between the two.

I got the F2 intake because it made 1 more hp on a dyno than the AEM . I didn't notice anything by putting the intake on for power or mileage. The only thing I noticed was the car is louder during harder acceleration. When it is wet outside, common sense would say avoid flooring it anyway. You shouldn't have to worry about Hydrolocking with a CAI. Just drive normal.

I like the F2 because it has a restrictor that can be removed IF you were to decide down the road to go with a more aggressive power setup (ie. Tuning, turbo, etc...). Plus the F2 is cheaper and a clean looking intake in the engine bay.

 

The AEM intake has a bypass valve that prevents water from entering the engine. So you will get a boost of power, minus the possibility of water entering the engine. Sounds like a win win?

 

unfortunately the aem intake (which i have) is only a one piece therefore does not have the bypass :/, as a matter of fact im trying to get a sri, i dont wanna have to hack-up my cai because i know ppl want it.

 

It is only one piece but you can purchase a bypass for 50 bucks. I think it is worth it!

http://www.advancespeedshop.com/aem-...e-p-11361.html
Bypass valve

http://www.autoanything.com/air-inta...A2052A0A0.aspx
AEM cold air intake

 

Geez, another fifty bucks for no real performance gain.

-- You just knew I'd have to yank your chain on this one sooner or later --

 

Maybe so, but I agree w/you Dale.
I also have the AEM in the form of the MazdaSpeed intake and had I not gotten a deal on it (STILL too expensive for what it is/does) I'd probably have left the stock air-box in there.
Another reason I wanted a CAI is to clean up the engine compartment a little bit... easier access to things. But $200 and no noticeable performance gain, then add another $50 on top of that, plus another $25-$50 for a "hydro" sock and someone has a real racket going for themselves.
I'm convinced that under normal driving conditions w/a relatively stock engine that a CAI/SRI is just not worth it.
Now if it were a regular weekend racer with tons of engine work done to it, and you needed a little extra edge, perhaps a CAI/SRI would help, but frankly its done nothing for me 'cept make my engine compartment look a little brighter.