Cool Air System

[rugbyben]

Can any one reccomend a good intake under $200 for my Imprezza Outback Sport. that is the 2.2L no turbo. I have heard of several options regarding short ram intakes but no actual cool air intakes for this car. anyone know why?

[Snowman]

If you're willing to do a bit of fab work and don't worry too much about how it looks, you could make one like I had on my ea82 wagon. I bought the pod filter from UniFilter (had to order from Australia) and the hose from NAPA. It cost me less than $100 total. I later added a cold-air duct to the filter from under the bumper, and a heat shield.

 

[Setright]

I just finished weeks of "development work" on my recently acquired Impreza, but its a Euro 2.0, and I think your 2.2 has a different intake system. Could you take a picture of your engine bay and post it? Or find a similar pic on the internet and post the link. I'll gladly share my experience - I spent many hours perfecting an intake for my previous car, a 2.2 Legacy, which is probably similar to your Impreza.

[rugbyben]

Thanks for the replies. here is a picture of the engine compartment, its not mine, but its exactly the same. Yes this is the 2000 2.2L non turbo. Impreza/outback sport. as far as i know the whole front is the same for the OBS and Sedan. it has the hood scoop and vents. I think I can use some sort of short ram intake to make use of one of the vents, but wouldnt an actual cold air tube inthe fender be better? P.S. gas mileage is important!

 

[blitz]

Remove the initial air intake section that draws hot air from the radiator (the one with the single bolt in the front), and replace it with a short section of aluminum dryer vent hose bent at a tight right angle like a short elbow and use that to draw air in from the hole in the fender.

 

This'll give you a 40* reduction in intake air temperature. That's a 4% increase in torque across the board for 2 bucks. Can't beat that.

 

 

Advantages:

 

Quick

Easy

Inexpensive

Effective

Torquey

Quiet (except for a nice added boxer snarl at 5k RPM).

 

If you're like me you'll appreciate not having to listen to the obnoxious honking intake drone that a performance intake will give you, and you'll also appreciate keeping the torque below 3k.

 

Also line the lip of the fender hole with a length of silicone tubing that you've slit lengthwise (just like for the Ganzflow intake) to keep the aluminum from rattling on the sheetmetal.

[Setright]

Blitz, I could not agree more on the importance of avoiding that intake drone!

 

I have tried a whole host of things with my EJ201 - same intake as in the pic - including a pipe directly from the filter box across the engine bay into the fender cavity. Despite using a velocity stack opening, there is too much echo and drone at full throttle.

 

I have settled on the following: Undo the front bit, one bolt and snap it out of the intake pipe. Block off the hole in the bottom of it. Save for re-assembly.

 

Undo the large resonator box, the first one that attaches to the bottom of the intake pipe. One bolt, a rubber grommet in the fender, and it should snap out of the intake pipe - don't break it, we're gonna use it! You may notice that there is a second fender hole, behind the one that's blanked off with a plastic snap-in plate. Mark the relation of the second hole on the side of the resonator.

 

Find a velocity stack/intake trumpet, motorcycle stores will most likely have some short ones, meant to be bolted straight onto carburators. 62mm diameter is ideal, not much room for anything larger. (2.5 inches)

Drill a hole slighty larger than the velocity stack, like 66mm, in the side of the resonator that faces the fender hole. Cut a piece of rubber hose to correspond to the circumference of the hole and split the hose down the middle, open it up and use it to line the hole. Squeeze the velocity stack into the hole, and leave it sticking out at least an inch.

 

Re-attach everything and enjoy the following advantages:

 

1) Looks stock, inspectors and police won't suspect anything.

 

2) Low end torque is still there

 

3) Oh, did I forget the RACE CAR INDUCTION NOISE at full throttle above 4000rpm??

 

4) There is very little noise at part-throttle - who spends time here?

 

5) ZERO extra noise at cruise.

 

 

Forget any hopes of using vehicle speed to force feed the intake, you need a turbo- or supercharger to do that :-)

[Caboobaroo]

PVC piping:D If you do it right, you can have a great cold air intake for less than 50 bucks I believe. Not hard just figure out how much you'd need and what kind of elbows and other attachments you'd need. My buddy put a snorkle on his Samari that way and it works great!

[Setright]

PVC pipes flex to much, they cave-in during WOT and create that plastic pipe echo that makes the car sound like you modded it at home - which you did.By the way, that resonator box I was talking about sticking a velocity stack in looks a quite narrow in the photo. You might need to extend it with a pipe to reach into the fender cavity.

[rugbyben]

So as i understand it from the above, if i get a really free flowing intake i will loose low end torque? I like the low because im not really a racer, at least not now, this is still my daily driver. But i do want it to perform as well as possible without ruining my gas mileage or making it a pain to drive in town.

 

Setrite, Im sorry but i am not understanding your instructions completely. I like the idea of using mostly existing parts, and i dont mind fabricating, but maybe you could clear up a few details for me and I will see if I can figure it out. the only thing is it seems like the parts used and the way the air will travel. it will make a couple hard angles. wount this actually make it more inefficient?

 

Also I like the ides of takin off only the front part, and fabricating my own cold air attachment. but I dont want to loose too much intake noise. Right now it is quiet below 3K and then has a nice growl above that, which i like.

Is that because of that box at the front of the intake? the one setrite is talking about using. you cant see it in the picture but it is about 6inches tall and 5 inches across and it comes down from the front of the intake and hangs down the front of the wheel well. i will have to look at it to see if it comes off with the piece i will be taking off.

 

Lastly, allong with this should i maybe take out the filter in the box and put on a high flow cone filter at the front of the system insted, or do you think a K&N for the box will do the trick?

 

And

[Setright]

Okay, in short terms my system is like this: The normal intake is blanked off. And I have run an aluminium pipe from the big box on the intake, into the fender cavity.

 

Simple as that. Still, a picture is worth a thousand words, so I will look into taking a few photos this afternoon (Europe) and posting them here :-)

 

 

Don't worry about the bends in the intake, and go for a panel filter, not a cone, especially if you don't want too much noise!

[Setright]

Dang it! Can´t access a digital camera, so I´ve done it the old fashioned way and drawn a diagram for you!

 

Please excuse my handwriting, my block letters always look like they were drawn by a three-year-old :-)

 

(And my cursive might prove unreadable)

SCAN0163_000.pdf

[rugbyben]

Thanks Setright, the picture was perfect, i feel stupid for not getting it before. Anyway it seems to be a pretty good idea. I may make a couple adjustments to it to eliminate the extra volume of unused space when just blocking the old intake, this may halp the flow be a little more dirrect.

 

Thanks for all the help and interest in the thred. I think I have my answer for now, but feel free to keep it going. I will post results maybe as soon as monday if i get the chance to work on it this weekend. The weather is expected to be sunny and 65*F here in PA. so i may have to take some much needed golfing time.

Lastly. Since I am modifying the front, what about the back? I have stock exaust, and not a lot of money. Should i swap for one of those turbo mufflers?

Do they do anything other then make a lot of obnoxious noise? Is there one that helps that isnt that loud?

[Setright]

WELL! It seems that again I am one small step ahead. I have bought a "Ninja" muffler via www.scoobyworld.co.uk and although they claim it isn't "intrusive in the cabin"....it is intrusive.

 

However, I can't be absolutely sure, since I haven't been able to get a 100% gas tight seal between muffler and the standard mid-pipe. After spending every evening last week under the car, trying different sizes and types of gasket only to find that each time it still leaked after a few miles, I have just ordered a new mid-pipe. The car is only four years old but the flange has rusted so much that the edges are frayed and there is not enough surface to seal against :-( Not even firegum could help.

 

I am going with a standard item, since I don't want to have problems getting the mid-pipe to seal against the cat system.....

 

My point? Examine the entire exhaust system before you buy anything. And if you don't want a loud car, make sure the pipe exiting the muffler is no more than 2.5 inches - the 4.5 inch on my Ninja creates a VERY low rumbling sound. Cool at idle, tiresome on the move...except above 4000rpm where the sound is very race car.

 

There is a discernible gain in torque above those same 4k revs, no doubt the car is faster.

 

Good luck :-)

[rugbyben]

sounds good. I will probably order from a company in the states though to save on shipping. I am just glad to know they make such a thing as a quieter performance muffler. those guys with the civics that sound like they just stuck a coffee can on the end of their tail pipe really piss me off. but i would like a more performance sound then stock, that has actual gains. there is such a thing as too much flow, some of these tuners dont seem to understand this. a 4" system on a 1.6L is going to do more dammage then good.

[Setright]

Yep, removing back-pressure will tend to reduce low end torque. And going overboard will reduce high-end power, since the engine will rely on the exhaust piping to maintain gas flow out of the cylinders. Too large a pipe and the gas will move to slow to "scavenge" the cumbustion chamber leftovers, and no amount of race-cam profile will help.

[Kostamojen]

Ill bring in some NASIOC/I-club N/A Impreza wisdom

 

The Cobb Intake is considered the best intake by far for the MAP based EJ series N/A engines (IE your car) good for 5-10hp depending on who you ask and what dyno it runs on, yet expensive ($280 new, ~$150-200 used . The Injen intake is also good, but its got alot of long piping and goes into the fender with a cone filter... Not as good of a design, and equally expensive, with almost the same power as the cobb.

Cheaper options are the J-bend intakes like Weapon-R (garbage), JC Sports (also garbage), and intakes you might find on Ebay... With those, you loose low-end, but have decent high end, and cost usually $150 or under. The problem is though that you just get hot engine air instead of actual cold air with these intakes...

Simple options include: Ganzflow/PDM style intakes, which basically are just a pipe that goes from the airbox with the filter to the fender. Dont do alot hp wise (2-5hp, closer to 2 IMHO) but are cheap ($75-40), but you can do the same thing with home-depot piping as suggested.

Another option is the throttle body cone filter... Basically you stick a cone filter on the throttle body and get air via the hoodscoop. A little custom tubing is involved to maintain engine vacume, but its just about the cheapest option (new cone filter ~$40, used can be had for about free )

[Tiny Clark]

P.S. gas mileage is important! ?????

 

And you bought a Subie for the MPG?

[rugbyben]

believe it or not i did buy a suby for better gas/mi. because it is better then my jeep wrangler but i couldnt make myself go back to a 2wd vehicle. i would destroy a honda civic in about a week with the winters here in central PA.

 

so i am trying to make the best of it, and have a cool car too.

 

I need to do something SOON!!!

 

My Fiance smoked me in her stock ford escort sportZX2

that dam thing is fast in a straight line.

and it only has a 1.6L , but it is a 16 valve OHC that comes stock with a performance cold air intake and the shortest clutch I have ever seen.

 

i think it gets more HP to the wheels then I do. it definetly accelerates faster and the RPMs stay lower. I know i shift better then her, but she can stay in her lower gears longer. ITS JUST NOT FAIR!

[ru4x4ever]

They make oem replacement Highflow K&N filters for the air box. Just do one of those and remove any hoses to the box or open the fender side of the air box. It will sound just like the cold air flow and alsohave the non-restricted air flow because of the new filter I did the sme thing to my uncles 2000 V-Dub.

-Sean