Pointless or useful?
 

I may not have my car yet dammit, but I still have some questions :p
Mainly I'm wanting to know how helpful a cold air or short ram intake is, the pros and cons, and can you live without one?
I've been told things like a CAI makes your engine work too hard or that its pointless anyway since your car was built to take in cool outside air. I can clearly see that short rams aren't terribly expensive but wondering if they help as well.
Also perhaps what in your own opinion would be parts that are advertised to help but don't, underappreciated or overlooked upgrades, etc.

CAI is useless on a WRX and may cause the car to run lean and hurt it.

Pro-Tune is basically a requirement for a CAI and on a WRX, you have to be up in STI+++ power levels to need it.

Pointless...even after you do a turbo swap the stock box is good up to 300whp or something like that. Most people put one on with a turbo swap because the car has to get retuned anyway. Save your money for something else...

Even the few intakes that are supposedly okay with the stock tune (K&N Typhoon, SPT, Cobb, Injen) typically aren't okay with the stock tune. They are, however, the easiest to tune for. Stay away from the AEM even if getting a tune for it. The SPT filter is known to fall off too so avoid that one too.

But, as Nick pointed out, if your making under 300WHP, you're just paying a bunch of money for a sound mod. Just remove the stock intake silencer and go stage II. It'll sound great and you won't have wasted money on an intake.

FWIW, I sealed the stock intake box to the fender and left the snorkel on so cold air gets blown into the fender and the intake box sucks it out of there. It's totally safe as long as the fender liner is intact. Probably doesn't do anything for power, but it doesn't hurt and it sounds great.

When you get your car, go stage II (TBE, UP if it it is a 2.0L, maybe IC Y pipe) with a custom tune and call it good for power mods.

The Cobb SRI with the Cobb cold-air box (and stock snorkus) is the intake that acts closest to the stock intake (tune-wise) of any out there. It is the only non-stock one I will accept when loading an off-the-shelf Stage 2 map onto somebody's car (besides the upcoming KSTech 65mm CAI's and 70mm LGT/08+ CAI's). Some people like the APS 65mm CAI but it always acted funny for me at part throttle and sometimes at idle.

The stock airbox is pretty restrictive. I measure about 40in.-H2O of pressure drop across at about 5 volts. There is some power to be had with a good intake, especially with tuning, but it is not a good mod (value-wise)for Stage 2 and below

How do I know this? I have installed and/or tuned and/or tested a couple dozen different intakes on my car and others'.