loserkid

iTrader: (1)

i was in the market and i was looking at some mods to buy. But do aftermarket intakes like injen, K&N filters, perrin short rams actually produce more power?

Wingless Wonder

iTrader: (7)

It's an ongoing debate but generally most Subaru factory turbo owners I know do not replace the factory airbox unless they have gone to a FMIC (front-mount intercooler).

Please read 'sticky' thread at the top of the thread listings in this forum.

--
0==WW==0
"…axles of evil…" - george w. bush

Imprezer

iTrader: (9)

Actually I have heard very good things about Injen. I will try to get my hands on one and test it for you guys.

VIBEELEVEN

iTrader: (2)

what about the k$n shorty or the apexi, both short ram and have a heat shield

Smooth_Ej20

i dont know much about how intakes affect subies but this is the theory for most turbocharged cars. Cold-air intakes do nothing, the turbo will only compress the air as much as it can whether the air is hot or cool, the idea is to get more air into the turbo by freeing up the intake, thus a short ram is all you need. Ever notice that all the major japanese aftermarket companies that make stuff for silvias, skylines etc. all make short ram. Cold air intakes are an american thing. Like i said thats the general theory ive never heard of having to do engine management on a suby with an intake, but like i said i dont know much about how intakes affect subies?

meilers

Not to ignite another endless debate, but the intake that is built into the WRX/STI from the factory is, in some ways, a cold-air intake; it sources air from outside the car (drawn in through the fender well) rather than from inside the engine bay like a short-ram or "pod" intake will. The issue isn't where the air comes from, it is whether that air is giving bad data to the MAF, which will then hand that data on to the ECU which can respond by pulling timing and giving you poor performance.

I would think a short-ram would annoy the MAF much more than a CAI which has the proper length and diameter to match the stock airbox. The APS intake is one example, where they maintained the exact tubing diameter and length of the stock air intake, but just took out the bends and kinks.

Also, that theory isn't actually why people dismiss the CAI for turbos. The problem is not the incoming air density (colder=denser), it is the fact that most turbos are so damn hot, even on the "cold" side, that any air coming in is already heated to several hundred degrees instantly even as it enters the turbo to be compressed -- negating the effect of the CAI. However, the fact that Subaru themselves purposely draw air from outside the car makes me suspicious of any intake that pulls air from the engine bay. The underhood temps on the WRX/STI are outrageous, compared to other cars I have driven; I think they are even hotter under the "bonnet" than my dad's air-cooled 911 Carerra.

VIBEELEVEN

iTrader: (2)

My impression was that most of the cais on the market have a different bend right before the maf that it isn't used to seeing
When I first got my rex I took out the resonater (so that the air was coming from the fender) and got a cel. So I got the gp moto silencer delete elbow and it never came back on. Thats been my experience with my car, just for referance

XkrazyAsianX

iTrader: (5)

Your best bet would just to get an K&N drop-in air filter, although i would like to hear what imprezer have to say about the injen CAI. If you've read the sticky, you would know the problem lays with the MAF sensor as stated above, it messes with the air flow numbers which inturn messes with the AFR (Air fuel ratio). This can cause your car to run lean which costs loss in performance and fuel efficiency. So i'd sugguest you to do the air scoop delete and put a K&N high flow drop in air filter. 40 bucks compared to the hudreds you'll have to spend on a CAI. Now you can take that lil money you saved and get a lightened crank pulley or something.

VIBEELEVEN

iTrader: (2)

Well said, I think that sums it up nicely.

Br1t1shguy

the stock intake isnt going to be restrictive compared to aftermarket with a stock turbo. After you start bolting on larger snails, fitment issues tend to dictate that you replace the intake with a short filter tube.

For the record, subaru doesnt draw air from the front of the hood for temperature issues, they do it to silence intake roar/turbo whistle.

sigma pi

iTrader: (6)

i have one if you want it

meilers

Hmmm... I've got a friend with a pod intake, and it didn't seem make that much more noise compared to stock (we both have '02 WRXs) after install. I noticed a MUCH bigger jump in turbo-related noise in his car after he installed a catless up-pipe a few months later.

In any case, the Injen intake we're discussing draws air from the fender. In fact, the Injen model looks almost identical (even in color) to the APS intake...

http://www.airpowersystems.com.au/wrx/my01/hfa.htm

http://www.injen.com/rs1201_mkt.html