My easy, tested to perform intake mods....

itsabimmerthing · #1 (**permalink**) 06-23-2007, 10:22 AM

Well, after wanting more power out of my BMW, and being bored, I decided to tinker a little. I went digging through my parts bin, and was trying to get some ideas. I very carefully examined the stock 325e air box system, and tried to see how power could be acheived. I know many people run an external filter, but can lose power without a heat shield. So, I decided to make do with what was given.
I first drilled some holes into the top half of the airbox, being careful.... I drilled two good size holes in the front of it, the part facing towards the grille of the car, two on each side, and two on the top. I figured this would let more air in. To test the theory, I put a peice of printer paper on one of the sides I drilled the holes into, to see if it was actualy sucking upon throttle. It held the paper in place, and when throttle was stopped, it fell.......
Then, after digging through my parts, I came up with a genious idea. A while back I had a PT cruiser, and put a CAI on it, and kept the stock parts, thank god lol. I had a little tube, which I beleive ran from the stock airbox to the fender. I will get the part number for you guys interested in it, you can get it at a chrysler dealer for cheap, or a junkyard for free basically. Anyway, I took that little tube, and seen there is a hose comming out of the bottom of the airbox once you take some plastic gaurd off. I took this tube, and forced it into that hose from the airbox. The tube fits in PERFECT, and SNUG! And since the tube has a small bend, when turned the right way, the open end of it goes right to a COMPLETE fresh cold air source. It is like a match in heaven. I will get some pics of this setup soon, as I have been busy.... Anyway, I put my hand over the end of that tube, and had my father give it some gas, and it sucks my hand right to it, so I know it is working! We took it around the block, and I can say it made a very noticeable difference. The stock airbox acts like a heatshield, but is still much like a CAI done like this. So 2 days ago, I go to autozone, and buy a K&N air filter to make the most out of my setup, and let me say, it is highly reccomended from me.... I put it in, and it felt much better, and sounds very good lol. With just the mods in my siggy, and this airbox work, the car feels very good, and torque feels awesome. I am very pleased with the airbox mod, and it will not waste your time, it is a quick procedure, and really does make a difference. I noticed the car spinning its rubber a little better now.

LeDevil · #2 (**permalink**) 06-23-2007, 06:23 PM

I'm kinda curious about this set up pics would be great

325i Phoenix · #3 (**permalink**) 06-23-2007, 07:41 PM

I'm pretty curious too. One of my friends actually tried something like this once. He drilled like 5 holes on the front face of his filter case on his civic. From what he tells me, it didn't really make any difference. Post some pics as soon as you can get them.

Much apreciated

Murphs · #4 (**permalink**) 06-24-2007, 03:05 AM

ah, you do realise that drilling holes in the TOP half of the airbox is letting in unfiltered air....

i dare you to go for a drive on a nice dusty dirt road

325i Phoenix · #5 (**permalink**) 06-24-2007, 10:13 AM

Wait, he drilled them on the top? Holy shit, I guess he did!

bergie_318is · #6 (**permalink**) 06-24-2007, 05:15 PM

one of my mates has a lancer, its a carby and on top of the air intake he drilled holes in it, but there was sufficent cold air getting in anyway because the pipe was in a really good spot. didnt do much accept when he changed gears at high revs it sounded like a blow off value haha was funny!

thats very true about what murphs said though, ud better be cautious where you drive around lol

itsabimmerthing · #7 (**permalink**) 06-27-2007, 02:27 PM

Funny, I havent noticed any problems........
Anyhow, I will get up some pics asap, still moving into my house, and need to get another USB cable as mine is lost lol. Either way, I did noticed a healthy increase.

Murphs · #8 (**permalink**) 06-28-2007, 04:12 AM

it's not going to be an instant thing, but cars have an air filter for a reason man.

yes there will be an increase, because you're skipping the air filter completely, it's definitely not healthy!!

Fad3.In · #9 (**permalink**) 06-28-2007, 12:04 PM

Quote:

Originally Posted by Murphs

ah, you do realise that drilling holes in the TOP half of the airbox is letting in unfiltered air....

i dare you to go for a drive on a nice dusty dirt road

Thats why i drilled holes on the bottom part! Anyway,no difference
worth talking about.Noise neither...
N.

NOMAD · #10 (**permalink**) 07-03-2007, 12:59 PM

If you drilled top and bottom then it'll pull dusty air into the engine. Over time this will wear out the rings and other items quicker.

I agree, bypassing the air filter gives a nice noise and throttle response. I undid the intake hose on a rented charger just for giggles. That thing was LOUD.

325i Phoenix · #11 (**permalink**) 07-03-2007, 08:31 PM

Quote:

Originally Posted by NOMAD

If you drilled top and bottom then it'll pull dusty air into the engine. Over time this will wear out the rings and other items quicker.

I agree, bypassing the air filter gives a nice noise and throttle response. I undid the intake hose on a rented charger just for giggles. That thing was LOUD.

Actually, drilling on the bottom wont bring any dusty air into the engine because it still has to go through the air filter, which in anycase seems pointless to me because unless you make some sort of port, you're still not getting any cold air, just a tiny bit more airflow through the small hole

NOMAD · #12 (**permalink**) 07-05-2007, 02:31 PM

emphasis on drilling TOP holes.
Lots of people "swiss cheese" the bottom of their airboxes for a cheap "hot air intake"

Fad3.In · #13 (**permalink**) 07-29-2007, 04:34 AM

Quote:

Originally Posted by NOMAD

emphasis on drilling TOP holes.
Lots of people "swiss cheese" the bottom of their airboxes for a cheap "hot air intake"

You dont really know what you re talking about,do you?

N.

NOMAD · #14 (**permalink**) 07-29-2007, 10:34 PM

Yes I do in fact know what i'm talking about.

Care to elaborate? Did you read with comprehension?

If you drill holes above the filter you bypass it and bring unfiltered dusty air into the intake manifold. itsabimmerthing posted this: "I first drilled some holes into the top half of the airbox, being careful.... I drilled two good size holes in the front of it, the part facing towards the grille of the car, two on each side, and two on the top. I figured this would let more air in. " which we are all responding to.

If you only drill holes below the filter then you still filter the air into the intake manifold.

If this is all you do then there will be less restriction into the filter but it will be heated engine bay air, not cooler ambient air, so the effects are slim at best.

I haven't done this, and probably won't ever do it, i just don't see the point except for noise.

All this is pretty elementary, it's been dicussed for ages by newbies to the car scene.

325i Phoenix · #15 (**permalink**) 07-29-2007, 11:38 PM

Quote:

Originally Posted by NOMAD

Yes I do in fact know what i'm talking about.

Care to elaborate? Did you read with comprehension?

If you drill holes above the filter you bypass it and bring unfiltered dusty air into the intake manifold. itsabimmerthing posted this: "I first drilled some holes into the top half of the airbox, being careful.... I drilled two good size holes in the front of it, the part facing towards the grille of the car, two on each side, and two on the top. I figured this would let more air in. " which we are all responding to.

If you only drill holes below the filter then you still filter the air into the intake manifold.

If this is all you do then there will be less restriction into the filter but it will be heated engine bay air, not cooler ambient air, so the effects are slim at best.

I haven't done this, and probably won't ever do it, i just don't see the point except for noise.

All this is pretty elementary, it's been dicussed for ages by newbies to the car scene.