I've been wondering where the hell the "swoooooshing" sound on my car is coming from.Its kind of annoying.It almost sounds like its coming from the glove box area. It does react with acceleration and when cruising i hear a steady but quiet "shhhhhh" sound.Is this the CAI ya think?
Yes they do make an audible difference. It's not in the exhaust note. The difference comes from the plastic CAI like you'd put on a civic. They hum when the air flows through them. Then there's the "hiss" as well.
Another thing, which has been said already is the removal of the air baffle. That will cause a noticable hum or drone.
Bit of advice I learned the hard way...
NEVER install a powerful e-fan and an inside the fender well CAI without a heat shield. The MAF goes nutso.
It drives me INSANE when I see people with the filter element in the engine bay. Its just too easy to run it the extra 6 inches into fender well, and there are too many negatives to keeping it in the engine bay.