DIY Cold Air Intake

Hey sorry about the wait guys, i've been really really busy setting things up for college. Hopefully this is still worth it to you, i love mine... gonna get some custom bends and make it a full CAI when i get the time.

 

any who, you need to start by getting a 3" cone of your choice (mine is just a cheapo ebay foam special, works good for 15 bucks though plus shipping) and a 3" air adapter, i think i got mine from carstuff.com... just need one that has the Subaru adapter for the year your car is. You also need some flat stock, anything that is 1" diameter and is about 12 inches long will do as long as it's not too thick.

 

then i suggest you use http://legacygt.com/forums/showthread.php?t=1955 this link to take out the stock air box, but stop after it's out. Jedimaster did a good job, and it's basically the same setup for the N/A cars. if you're smart enough to know you can do this you'll manage.

 

after the air box is out you take the MAF sensor out and put it on the adapter and connect it to the air hose going into the throttle body (making sure to test fit the cone, mine was a tight fit so i put it on the adapter previous to attaching the MAF sensor) then just tighten things down on the half that the adapter connects to the stock hose.

 

then you take the flat stock and drill a 1/4 inch hole in the center and about 1/2 an inch in so it can be bolted to the brake fluid tank mounted to the fender. about an inch in from the end you drilled a hole in you put a 90 degree bend then another one at 7-7 1/2 inches from the bend, then another 90 about a half inch or as much as you think necessary to use as a lip where the hose clamp attaches the air cone and adapter.

 

after everything is tightened down you need to reset the computer otherwise the engine will run very hard because of the fuel mix problems. you do this by disconnecting the battery terminals and touching them together for about 30 seconds, i usually do it for about a minute just to be sure... or however long i feel like holding it.

 

then you have a nice cheap cold air intake kit that cost me under 50 bucks.

 

pics below to help... if i left anything out or have any questions let me know.

That is not a COLD air intake. Your stock system was a COLD air system. That is sucking hot air, making lots of noise, and probably throwing very turbulent and inconsistent MAF reading.

 

$15 "cheapo ebay filter"?! are you sure this is really what you want your car to be breathing through?

That is not a COLD air intake. Your stock system was a COLD air system. That is sucking hot air, making lots of noise, and probably throwing very turbulent and inconsistent MAF reading.

 

$15 "cheapo ebay filter"?! are you sure this is really what you want your car to be breathing through?

 

technically yes...BUT the black tubing really sucks up engine hit badly and it gets pretty fricken warm.

technically yes...BUT the black tubing really sucks up engine hit badly and it gets pretty fricken warm.

 

$50 will get you a lot of thermal wrap.. Don't know that I've ever heard of that being done to the stock intake plumbing though.

I'm a huge fan of ingenuity, and I wouldn't want anything to stop you from modding how you please... but for some reason I don't think this has been thought through all the way.

good work doing a diy project, though I would recommend this to nobody. there is nothing wrong with a stock system + good filter.

 

If you would have slapped on a better filter my response might have been different.

first i gotta commend you on a good writeup and some handy work

 

i dont wanna sound too harsh....

 

but that is a disaster

 

-you have a poor quality filter that could come back to haunt you in a BIG way

-you destroyed the pre-MAF path the ecu was tuned for

-you have turbulent ribbed pipes form there

-THEN theres a plenum

and all the air coming trough the thing is hot

 

this is systematically worse then stock in every way.

 

im only being rough because i want you to have a cool fast car to drive and i dont want anyone else to ruin that either

 

the most ideal intake retains all stock piping to the MAF because the airbox is nonrestrictive and your air-fuel ratio is more important than flow. put a quality high flow panel filter in the box and and runs clean, metal, after market tube from teh maf to the TB (search for the hybrid ebay SRI writeup)

 

disclaimer- this rightly assumes you're not tuning your car to a nice engineered CAI or something and that the engine pictured is the one in question, as my research may not necessarily apply to the newer gen

how does it sound. i dont think there are many 2.5i intakes out there. Keep working on it.

what kind of vacuum/ idle bypass type lines (if any) needed relocating?

how does it sound. i dont think there are many 2.5i intakes out there. Keep working on it.

 

 

it sounds great. but like i said, this was just a temp until i get the rest bent.

what kind of vacuum/ idle bypass type lines (if any) needed relocating?

 

there aren't any, you just take the stock box out and put the rest in... might also consider putting a 45 bend in it to place it in the spot where the stock box is located

good work doing a diy project, though I would recommend this to nobody. there is nothing wrong with a stock system + good filter.

 

If you would have slapped on a better filter my response might have been different.

 

 

 

this is a trial and error based thing, i am soon planning on putting more tubing on to place the cone more towards the bottom, i don't have fog lights so i took the black plastic panels out to force more air into the area where the intake silencer was.

first i gotta commend you on a good writeup and some handy work

 

i dont wanna sound too harsh....

 

but that is a disaster

 

-you have a poor quality filter that could come back to haunt you in a BIG way

-you destroyed the pre-MAF path the ecu was tuned for

-you have turbulent ribbed pipes form there

-THEN theres a plenum

and all the air coming trough the thing is hot

 

this is systematically worse then stock in every way.

 

im only being rough because i want you to have a cool fast car to drive and i dont want anyone else to ruin that either

 

the most ideal intake retains all stock piping to the MAF because the airbox is nonrestrictive and your air-fuel ratio is more important than flow. put a quality high flow panel filter in the box and and runs clean, metal, after market tube from teh maf to the TB (search for the hybrid ebay SRI writeup)

 

disclaimer- this rightly assumes you're not tuning your car to a nice engineered CAI or something and that the engine pictured is the one in question, as my research may not necessarily apply to the newer gen

 

 

just to let you know that is completely stock except for the bracket, cone, and adapter for the MAF, and i'm getting better gas mileage to let ya know, so something must be working. it's probably because i removed the plastic panels where my nonexistant fog lights go.

resetting the ecu served you well.

 

can you feel a difference in low end torque?

That is not a COLD air intake. Your stock system was a COLD air system. That is sucking hot air, making lots of noise, and probably throwing very turbulent and inconsistent MAF reading.

 

$15 "cheapo ebay filter"?! are you sure this is really what you want your car to be breathing through?

 

Amen to that. The stock airbox is more than sufficient for the majority of LGT pilots.

 

I'd never, ever let my car breath thru one of those foam pieces. Even the high dollar HKS 'green mushroom of death' and similar parts from other reputable manufacturers start coming apart after awhile. You don't want to ingest that.

resetting the ecu served you well.

 

can you feel a difference in low end torque?

 

 

all i can say is that she takes off, and sounds amazing at the 3-4 grand mark, stopping at a parts store today to see the damage on putting plastic bends on to put the cone more towards the opening and replacing where the rippled stock pipe goes, leave the box thing that connects straight to the throttle body. that shit-cone is only temporary til i decide with who i wanna go with for a good one.

New filter necessary

I am gonna go ahead and say your car will be slower and on a real hot days your going to have problems. The extra noise you hear when acceleratingly does not make your car quicker. Also all these extra bends your gonna be putting in to get the filter down out of the hot engine is going to cause a whole heap of bad air flow. Plus your car is tuned perfectly for the stock setup not a mile of bendy hoses and cheap filters.

 

Other than that good write up.

Do most of you guy realized this is not a LGT, it is a 2.5i. There is power to be made on a properly setup intake, even if under the hood still. The only real problem I see is the MAF may now be thrown off.

Do most of you guy realized this is not a LGT, it is a 2.5i. There is power to be made on a properly setup intake, even if under the hood still. The only real problem I see is the MAF may now be thrown off.

 

Properly set up is the key. Nothing here looks like it would lead to gains.

 

Edit: I should add to be constructive, that I commend the OP for undertaking the project. However, it would be good to go back to the whole Cobb vs SPT intake debate way back when and see just how finicky setting up an intake for actual gains is, and how well the stock box is actually designed.

don't worry guys, just found an aem intake kit for an 02-03 wrx that i'm pretty sure i can make work

... looks like it's gonna be completely upside down though lmao. if i get it.

can somebody just post pics of how they did theirs?

 

 

Somebody stole your turbo !!!

can somebody just post pics of how they did theirs?

http://img78.imageshack.us/img78/8995/dsc0084fy5.jpg