Airbox Drilling

[Eurospec]

Who's done it and what are the pros/cons?

[kowalski]

Who's done it and what are the pros/cons?

i'v done it.

so had it for like 2 years. only difference i noticed was sound. no difference inf fuel econ. or power.

[Febi Guibo]

I don't think there are too many pros... the stock BMW pleated filter and airbox, esp for our cars, is pretty good.

...having said that, I love the sound of my ricey cone kit... guilty as charged... lol!

[bmwman91]

I don't think there are too many pros... the stock BMW pleated filter and airbox, esp for our cars, is pretty good.

...having said that, I love the sound of my ricey cone kit... guilty as charged... lol!

Hehe. Yeah, that's the only reasson I kept my intake on the 1st car...it just sounded too mean to take off. Once my MAF conversion is done I will probably be using a cone filter (though I COULD make an airbox adapter).

Yeah, do not wreck the factory box. It'll probably hurt power if anything since you will be sucking in hotter air.

[e9nine]

Believe it or not, my throttle response changed a tad. I did a comparison last week. I'll try again in a few weeks to make sure it's not a placebo thing. Hot air is sucked in regardless in my case as I don't have a the backing plates behind the headlights and I really don't need all the power in stop-n-go traffic :cool:

[dino245]

I have a complete airbox because the load noise with out it gets old after a while of daily commuting.

[kowalski]

I have a complete airbox because the load noise with out it gets old after a while of daily commuting.

try running a straight pipe...

[1991318is]

try running a straight pipe...
That's why I bought my m42, got sick of a built v8 w/ very little in ways of exhaust or things to make it comfortable, it gets old quick

[e9nine]

If you have an aftermarket muffler, the noise effects are balanced out. I did a muffler swap prior to the airbox drilling and the exhaust droned out the engine, it's now almost in a 50-50 equilibrium :)

[hamann318is]

I have a drilled intake and a muffler. It's nice.

[kowalski]

That's why I bought my m42, got sick of a built v8 w/ very little in ways of exhaust or things to make it comfortable, it gets old quick

yeah, i had a 1068 chevelle with a very built up bored out 350. dual side pipes. loud as hell, but it got stolen before it got anoying:(. now i have a 56 belair with dual 2.5 inch mendral bend stainless steel exhaust with close to 600hp.

good news! i finaly found amuffler and its being put on on saturday!:)

[GrippyDrifty]

WOW!!! A 1068 Chevelle huh? Jk.
My stock airbox does have a nice whistle to it, but I hear that a cone kit takes it to another level.

[bmwman91]

Where did you all put the holes? And how did you avoid sucking in hot engine bay air?

[e9nine]

I drilled the holes on the left side (D.side of the boX) which is closest to the fender. Hot air will obviously be sucked in during stop and go, however I have taken out the headlight plastic backing piece so once the car is on the roll...all is well with fresh air flow.

[kowalski]

WOW!!! A 1068 Chevelle huh? Jk.
My stock airbox does have a nice whistle to it, but I hear that a cone kit takes it to another level.


haha yeahg you never heard of the 1068 chevelle? its REALLY OLD and worth MILLIONS...... :)

[sheepdog]

I cut a hole in the left side and a bit of the bottom on the left as well for mine.

Did it help, I am sure it did.

There was a retrofit(?) from BMW to the air hose from the box to the front of the car which added a spring, without it, that hose collapses. Putting holes in the box removes that possibility.

Like E9nine said, at stops, yes hot air is sucked but when moving it should be fine. It definately breathes a bit better.

As for noise, with the way mine is, under normal driving it is pretty quiet. at 1/2 to 3/4 throttle though it really gets noisy, but who cares when you are on it.

I like to say it scares women and small children. You can hear me coming if I am on it for a quite a distance (good for getting deer out of the road), but cruising is barely above stock noise levels. I like it. Definately turns heads around town when you punch it.

[///Motorsport]

it gets old after a while of daily commuting.
on my wrx i have an electronic cutout so for around town and police its stock subaru quiet and when i want some angry noises i have cat-less exhaust off the 3" downpipe..

[M42boy]

I'm swiss cheezing my airbox next time it comes out and new "upgrade" air cleaner going in. Why not!!! Should at least sound cooler, if nothing else.

[D. Clay]

Does anyone know where on realoem.com that baffle behind the headlights is? I am a believer regarding the intake air being as close to ambient as possible. My baffle is also missing. I've had the outside air temp sender under the hood and here in Texas it will go to 108-110 degrees at a red light.

[bullmand]

Can someone post pictures of a drilled airbox? I've done the Fogg thing on my M44 318ti, but the airbox on my new-to-me '91 318i is much different than that one.

[M42boy]

Does anyone know where on realoem.com that baffle behind the headlights is? I am a believer regarding the intake air being as close to ambient as possible. My baffle is also missing. I've had the outside air temp sender under the hood and here in Texas it will go to 108-110 degrees at a red light.
I've got the trim piece that goes behind the driver's side headlight soaking in my bathtub right now. I can get you a part number when I get home.

Mine were all dirty and needed a bath! :cool:

Does anyone know where to get that screen piece that replaces the driver's side high beam? That's gotta help flow fresh air!

[e9nine]

Does anyone know where to get that screen piece that replaces the driver's side high beam? That's gotta help flow fresh air!

DIY from an old speaker grille or chicken wire style mesh from Home Depot, Loews etc. I made one from a 6" or 5.75" speaker grille but junked it as it didn't "flow" right to my tastes :rolleyes:

[sheepdog]

Just cut out the front a bit and the fender side, while maintaining strength.

That is all you need to do. Mine sounds incredible.
Sounds better than a cone filter, that is for sure.

[///Motorsport]

can't you just de-baffle the airbox? and i dont think cone-filters are ricey if they have proper heat shielding. all it takes is some duct tape, tools, and aluminium from ACE.

[Minkee]

well guys i owned a car for 4 years with a drilled airbox. Granted it was a 8v vw, the drilled box did increase throttle response, but not necessarly the power overall. Honestly a cone filter sucks hot hair, but its more air. You'll get a little performance boost at 55+, but not much power gains at lower speeds.

[gjuuu]

can't you just de-baffle the airbox? and i dont think cone-filters are ricey if they have proper heat shielding. all it takes is some duct tape, tools, and aluminium from ACE.

Here is mine.....I have posted this on every other forum I visit so why not here as well...hahahha
http://members.dodo.com.au/~wawawa/CAI011.jpg
http://members.dodo.com.au/~wawawa/CAI008.jpg
http://members.dodo.com.au/~wawawa/CAI013.jpg

At WOT it screams ..... and looks so much nicer than stock
http://members.dodo.com.au/~wawawa/CAI001.jpg

[D. Clay]

Here is mine.....I have posted this on every other forum I visit so why not here as well...hahahha

At WOT it screams ..... and looks so much nicer than stock
Very good looking and also very functional. A guy on another forum told me once that the air temperature didn't matter because the computer adjusted the air/fuel mixture back to stoichiometric. I've even seen those cone filters right behind the radiator resulting in a net HP loss. Going from 110 to 80 degree air results in a 3-4 HP gain from an M42. There's a high pressure area at the base of the windshield that is really good for an air intake. It's hard to access unless you have a track car that you can cut up a little and can forgo incoming air to the passenger compartment.