Air Filter/Air Intake

keita · #1 12-06-2003, 12:17 PM

Hey Fellas, got another question.
Got 2004 WRX with no mods. I'm not really that much into fixing my car up (yet), but I'll do simple things like changing spark plugs and getting a new air filter and such....

Tell me your experiences/opinions on air filters. K&N air filter, worth it? Notice any changes in performance?? What about cold air intakes??
Is it one of those things that you won't feel any difference unless you make mods on other parts of engine/exhaust, like uppipe, exhaust, etc.?

F23A4Racer750IL · #2 12-09-2003, 09:20 PM

yea the K&N is pretty good. and if ur not goin all out a Turbo XS shorty Intake is pretty good to. so is a Greddy Airnix filter. u'll feel some difference but its not gonna be earth shaterin. and u'll get a pretty nice sound to.

naylor · #3 12-09-2003, 10:23 PM

I have a JC Sports short ram intake. I never really heard of the company before, but it was on the car when I bought it. According to the website, it's suppose to be pretty good and brags about 13HP gain. It didn't mess up my mass air flow sensor and sounds pretty good so ya could look into that.

ragnarok720 · #4 12-10-2003, 03:18 AM

I have an AEM Cold Air Intake, not the short ram. It works pretty well. Didn't notice any real hp gain but did happen to notice that the boost was held slightly better and without hesitation when bumped up.

WRXED · #5 12-10-2003, 02:15 PM

Dude I destroyed cylinder number 3 w/ an intake and bad tuning on my part so I might be a bit biased

The truth is intakes on a wrx can make the MAF nutty and cause the engine to run dangerously lean, which will cause knock. If you insist on it because your hard headed like I was =) dont run the intake without an ecu that will propery manage it.

The stock intake isnt at all restrictive, remove the snorkulus if you haven already done so and drop in a good panel filter. Use the extra cash for a catless upipe or downpipe. You'll notice a big diffrence in your rex once you start removing the cats.

Thats my 2 cents

MB38 · #6 12-10-2003, 02:51 PM

Spend your money on intercooler hoses. You'll get real power and no nasty side effects. If you haven't already, remove your intake silencer snorkel; check here for instructions. Then just start saving your pennies for an ECU flash.

keita · #7 12-10-2003, 06:58 PM

fellas, thanks for the replies/advices. I've heard of hacking that silencer snorkel, but it sounds like all it does is increase the noise, and allowing you to hear the turbine spool.... I'm not sure if I necessarily want that. I have been thinking about Vishnu stage 0, but I'm wanting to do some easier things first...

MB38 · #8 12-10-2003, 07:53 PM

Intercooler hoses. An honest 10whp gain for $160.

ragnarok720 · #9 12-11-2003, 12:51 AM

wrxed, the coldair intake didnt make it too lean. Other things had to have been a factor such as boosting the turbo way too high?

MB38 · #10 12-11-2003, 10:45 AM

If you run too much boost, the air still gets properly metered right up to the fuel cut. I too have seen air intakes cause the cars to run rich. Unless you buy the intake and *then* have your ECU tuned with the intake in mind, it isn't worth it. Again, intercooler hoses if you want a cheap upgrade.

ragnarok720 · #11 12-12-2003, 01:09 AM

My car runs rich from it. Assuming that the intake would make the car run lean, even slightly, it wouldnt be near enough to cause that much detonation. Really only the turbo is gonna cause that kind of detonation

F23A4Racer750IL · #12 12-14-2003, 08:35 AM

i herd that WRX's computers suck. so its a good idea after bolt ons mods. to get an ECU upgrade like a Turbo XS UTEC.

MB38 · #13 12-14-2003, 12:44 PM

Regardless of what you "herd," they're actually remarkable pieces of hardware and software which do an unbelievable job of controlling the car. As a result, most changes to the ECU are done by reflashing or by piggy-backing onto the stock ECU. That way, you retain the disaster-avoidance and variability of the stock ECU but get the improved performance that aftermarket upgrades bring.

midknightwrx · #14 12-19-2003, 12:53 PM

Quote:

Originally Posted by ragnarok720

wrxed, the coldair intake didnt make it too lean. Other things had to have been a factor such as boosting the turbo way too high?

Actually, I put a cold air intake on my wrx and within 2 minutes of driving, I got a CEL - misfires in all 4 cylinders. Got lots of knock with it too. The problem with CAI's that they usually either have a bend right before the MAF or the piping where the MAF resides is a different size than the stock piping. Either of these 2 conditions will make the MAF read incorrectly and can most definitely do some nasty stuff to your motor if you're not careful. There are plenty of documented instances of CAI's causing misfires and detonation. If you want a new intake, get either a short ram intake (Blitz SUS, TurboXS, Perrin, etc.) or upgrade the stock Panel filter to a K&N, ITG or Perrin Panel filter.

Like others have said though, there are definitely better ways to spend the cash. The stock airbox is not restrictive until you upgrade your turbo.

(Note-CAI's make no sense in a turbo charged application. The amount the turbo heats up the air as it passes through will totally nullify the coolness of the air that the CAI brings in.... That's what intercoolers are for....)

ragnarok · #15 12-20-2003, 02:21 AM

ok, if they dont make sense then how come every other extremely modded wrx ive ever seen pretty much have a coldair intake? I've installed plenty of coldair intakes on plenty of cars and none of which effected anything on the car. Something was probably wrong prior to the installation or your MAF sensor was already tweeked. Did you by chance when taking it off the airbox touch it on the spike? That will mess it up. Anyways, once hi-boost is caused airboxes tend to become restrictive. The more air the coldair intake brings in while help your car out a lot.

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