drilled airbox?

[snoops]

ive noticed a lot of cars with drilled airboxes, what does this do? if i was to do it do i drill above or below the filter?

[E30Mark]

Think about it, would you really want to drill the box AFTER the filter?

I know some people drill the box on the underside, do a search, this has been discussed to death in the past...

[e30sport32]

hi fella ive done this on both my tec1 and tec2 all you do is remove the complete air box un clip the bottom half as if you were changing the filter, take out the filter and drill lots of holes through the bottom half i used a drill with a 20mm spade bit that drills holes in wood, drill as many holes in the flat surface as you can then give it clean replace the filter and box and bobs ur uncle,

it gives a standard look but a bit of a induction roar and i found the car to be slightly more responsive breathes alot better so can only be a good thing hope this helps,

[Jimbob]

I guess the filter would need changing a bit more often though?

[snoops]

thanks for the info ill get on to it tomorrow when i get my k&n panel filter

[Brianmoooore]

ive noticed a lot of cars with drilled airboxes, what does this do

Makes a quality car sound like a boy racer special and feeds warm air to the engine.

[zimmerestate]

i wouldn`t bother if it mad a good diffrence or mad i quicker etc what it doesn`t dont u really think bmw would of made them like it from the factory no they didn`t and bmw probley spent thousand making and designing the car to its best so id leave it as it is

[fuzzy]

i wouldn`t bother if it mad a good diffrence or mad i quicker etc what it doesn`t dont u really think bmw would of made them like it from the factory no they didn`t and bmw probley spent thousand making and designing the car to its best so id leave it as it is

all cars are built with compromise in mind between various things including cost and economy.nothings perfect and can always be improved upon,how ever small.

[gooner1]

i wouldn`t bother if it mad a good diffrence or mad i quicker etc what it doesn`t dont u really think bmw would of made them like it from the factory no they didn`t and bmw probley spent thousand making and designing the car to its best so id leave it as it is

Agree about the airbox but people also fit chips, bbtb,s and 6branch
manifolds which release extra power.Some things move on and can be improved on.

[zimmerestate]

i agree with both of you i just think drilling an air box is a really poor way to mod your air intake

[Geoff]

i agree with both of you i just think drilling an air box is a really poor way to mod your air intake

Mate if your on a budget, or have no dollar then why not! Were not always at the traffic lights trying to race everything and everyone. Makes it sound a little meatier so why not!?

Go for it.

[fuzzy]

Were not always at the traffic lights trying to race everything and everyone.

speak for yourself mate

[ajm-e30]

cold feed the airbox instead mate

[Simon]

cold feed the airbox instead mate

It should already be, can't get much better than the standard system, pipe from the bottom of the airbox to a cover that clips to the headlamp cover, making sure the air is taken from the grill at the front of the car.

[snoops]

do i have to remove the whole box including the afm? as i tried today by unlocking the two bolts closest to the edge of the car and unclipped the clips but couldnt remove it?
can i just drill into the box while its on the car ithout removing the box?

last of all its a bit of a long shot has any1 got any sound clips of there car with drilled airbox?

[Ziggy]

I had a certain ford v6 a few years ago, which had had the entire bottom of the airbox removed. The previous owner had obviously changed their mind though, & stuck a bit of plastic over it again... which fell off... I thought the car was gonna take off from the amount of noise it made. & I've tried various filters etc on various cars...

My conclusion is that it'll make no difference to power, but will increase induction sound (how much by will depend on how much material you remove!). This is better than forking out for a k&n (etc) cone filter which'll make the same noise & actually reduce power (as well as dubious filtration performance on some of them).
If you want noise then do it, but don't expect to feel it on an even vaguely well tuned ar$e dyno!

[tim-ix]

I did this to a K-Jet Golf many years ago and it does sound very loud. The induction bark when combined with a K&N is brilliant.

[snoops]

yeh thats what im looking for as its abit quite for me as standard,

lol back to the question can i drill the holeswhile the airbox is on or do i have toremove it all, if so how?

[Ziggy]

Remove it first otherwise there'll be lots of li'l bits of plastic in there to clog up your filter, & I have no idea how you'd get to it without removing it anyway...

Just take the bottom section off the same as you would when you change the air filter (you do do that don't you? Now's the time otherwise...). It's just spring clips holding it on - no bolts - & just a bit of wiggling to get it out.

Don't drill too many holes to start with, & I'd try & keep them on the wing side in a (probably vain) effort to minimise the hot air you suck up.

[snoops]

lol thanks for the info ill giv it another try 2mora, cant i just leave the current air filter on there? what will happen if i dont change it?

[Ziggy]

Because if it's a standard paper filter that's not been changed in goodness knows how long, it'll need changing! Maybe someone else does your servicing & it's been done recently?

[Brianmoooore]

do i have to remove the whole box including the afm? as i tried today by unlocking the two bolts closest to the edge of the car and unclipped the clips but couldnt remove it?

There's a cable clipped to the engine side of the airbox, and a pipe clipped to the back end. Disconnect the air intake pipe at the front, the large convoluted air hose and the AFM electrics connector.
Remove the two 10mm nuts and the whole assembly lifts out. There is a rubber buffer which sits in a U shaped bracket at the bottom of the mount.
This rubber buffer may stay behind or stay on the air filter, or drop onto the floor. Make sure it is refitted.
How long have you had this car? Air filter is a very basic service item, and a blocked one will send your fuel consumption up and your performance down very effectively!

[snoops]

iva had the car about amonth but it had a new air filter a couple of months ago about 3k miles, its running fine i was just asking if i drill the holesdo i have to get a new filter

[noney82]

doesnt the engine run better with cold air?

[Ziggy]

No, only if it needs it - just sounded from your questions like you'd never done it & therefore it probably hadn't been done in ages - don't worry about it if that ain't the case!

[Ziggy]

doesnt the engine run better with cold air?

Yup. But it's not gonna make a lot of difference...

[noney82]

so why do they come with the air intake pipe next to the headlight,

[Ziggy]

Don't get me wrong - it will be better for performance if left standard. But the differences aren't big, & if he wants a bit more noise I say go for it - a new airbox costs pence anyway.

The air intake does indeed provide colder air, but it also reduces noise - BMW designed em to be quiet & that's not what some people want...

[noney82]

i know what you mean, i had a cone filter on mine but it started to rip the air intake but so i need to make a bracket for it,

[Ziggy]

As I said earlier - I'd rather have a standard airbox (drilled or not) than your average cone. Not because of the heat issue (make a heat shield...) but because they're usually shoddily made, poorly designed (no internal trumpet etc), & I doubt they even filter the air that well! That'll be why I sold the K&N that came on my car...

I'm hoping for more from the ITG that should be on its way to me though

[Brianmoooore]

Why anyone would want a noisy intake is beyond me, but, if that's what rocks your boat....

[noney82]

dont k&n do cones i use to have one on my nova (stop laughing lol)

[Ziggy]

dont k&n do cones i use to have one on my nova (stop laughing lol)

Yep - that's what was on my car when I got it. Nice noise ( ) but I got shot ASAP for all the reasons mentioned above. Plus I wasn't gonna pay my insurance company to have it fitted!

[ChizFab]

i no its on a ford but,

in an old fast ford mag a couple of years back, they featured a rolling road, where various modifications were tryed out on a 90spec escort xr3i. they actually found that drilling the airbox gave somthin like 3 bhp more than any of the aftermarket filters such as k&n, green etc!!!

lol thot is was great at the time n promptly set about my mates 3i with the drill!!!!!

[lancelot]

One of the previous cretins who owned my M3 did this mod. Totally pointless. Think about it, you have a pipe, air goes in, if you the cut holes at the bottom of the box the air will take the route of least resistance, ie instead of going up through the filter it goes straight out through the drilled holes. Therefore you reduce the amount of air your engine flows, which ultimately reduces power. Possibly one of the most stupid mods I have ever seen. Don't do it.