i've heard all the talk, and the debates, and BAN SUV's post nd nic3krnnamja's posts sufficiently cleared up every question I've had about putting any sort of intake into my car.

thanks

 

cold-air goes into the fenderwell to suck in the air. The short-ram's filter is in the engine compartment

 

They both have the same flaws. If you get nit-picky, a CAI is better because it picks up cooler, denser air.

 

Not necessarily so, according to "Train your WRX" book. To be honest, the stock intake is very well designed and you really dont need anything else unless you are running a HUGE turbo and pushing over 300HP...

My advice: save your money and get mods that matter (like suspension and such...)

 

There are simply too many 'Awesome' tuners who are split 50/50. Which leads me to believe that either the ones who are 'con' wrt aftermarket intakes have seen too much variance among the different makes of intakes. Or the ones who are 'pro' are just hucksters telling the market what they want to hear just to make a buck. That's why I think it's important to research and come up with personal conclusions.

Facts are that aftermarket intakes do allow less restriction than the stock box (snorkus or not). They also are less prone to turbulent air vs. the stock box. Do these criteria even matter, one way or the other...is more air with less turbulence good or bad.

Another fact is that the amount of heat that is post turbo (even post intercooler) is directly related to how much work the compressor side of the turbo had to do in order to compress however much boost you've asked it to. It doesn't matter a hoot what the ambient temperature is.

What is speculation (might be true, might not) is that the MAF is particular to seeing a set amount of airflow. I do believe that the MAF is a tricky mechanism for a novice tuner, like myself. But bottom line is that it simply translates airflow into voltage. I don't buy that there is some 'value' for cfm that the car or ECU is programmed to expect and recognize. Because there is more air isn't necessarily going to fool the MAF into transmitting an errant voltage. Nor is the aftermarket intake going to be any more erratic in the amount of air it sends than the stock box.

Citing Corky Bell, in reference to a restrictive intake filter vs less restrictive, he says, "So here the odd circumstance exists that flow is down, boost remains the same, and the pressure ratio goes up. Net result is that power is down and heat is up....The idea that the turbo is told to make the same amount of boost out of less air logically means it must work a bit harder to do so. The harder it has to work, the more heat it makes."

Nhluhr did his OWN testing (which is probably not the best solution for everyone, but it is still relevent advice). Here is the conclusion he came to. (hopefully you can access the link)

 

I had an injen and took it off. My car felt way faster after I took it off. Don't know why, and don't care.

In my opinion, the stock box works great and I am going to stick with it. The only advantage I saw in two years of having a CAI on my car was the wicked spooling sound.

Bottom line: I have never seen a dyno graph showing a CAI making more power than a stock airbox.

 

They exist, but you have to take them with a grain of salt.

 

Has anyone put the stock intake system (from the under hood scoop to the MAF) on a flow bench to see what it flows? Is it possible that it flows MORE than enough air for a 2.0 turbo?

I know from tuning, dynoing and racing air-cooled VW's, they will run the best numbers on cold, dry days, but we are talking ancient Weber 48IDA carburetors, no engine management and reading spark plugs with a magnifying glass. But combustion cycles are combustion cycles. I ask this question:

If EJ20 "A" (stock) was dynoed at sea level at 60 deg F and a barometric pressure of 30" Hg

And EJ20 "B" (stock) was dynoed at sea level at 90 deg F and a barometric pressure of 30 " Hg

Would there be a power difference??

 

Indeed there is, because all turbo cars get stronger as the air gets colder (read: denser) right up until they start knocking from being too lean. But every good dyno takes ambient conditions into account. In fact, the easiest way to inflate dyno numbers is to allow the intake air temp sensor to touch something hot, like the radiator or manifold. Instant increase in horsepower.

 

how's the induction/spooling/blow-off sounds from an aftermarket intake vs. stock after the snorkelectemy??

 

It's about the same. Maybe a little louder with an aftermarket intake.

 

ah, good to know. I was looking into maybe getting an injen just for the sound (I LOVE a nice gulping induction sound.. and hearing the turbo), but after reading your post about the MAF calibration I'm leaning towards just de-snorkling the stock system.

if I understand your explanation of how they calibrate the MAF sensor though, wouldn't de-snorkling also throw off the signal?