Air Filter Question - no.243

[minime1275]

I've seen a few posts on this site asking which after-market air filter is best for the E30 and many people think standard is best.

Yesterday I took my standard 320 for a quick blast up the road with no filter on (I unclipped the bottom of the filter box) just to see what it sounded like. I thought it sounded fantastic when the engine was under load!

Unfortunately you cant drive around without an air filter, but I loved the induction roar that it gave me. Im not after BHP gains, just wanting to enjoy the noise of my cheap old straight-six, so are there any cheap filters on the market that increase the induction noise without losing BHP?

Im aware that Id have to somehow channel cold air to the new filter, but I dont mind having a go a some fabricating.

Any recommendations?

Neil (im not a chav!)

[Davenotouring]

You'll not get the noise of 'no filter' with a filter, but you will probably get a better noise by replacing the standard panel filter with a K&N panel filter, which also has a lifetime guarantee!

[jmc330i]

I broke the botom half of my standard air box on my 325i and it was a couple of weeks before I did anything about it.

Just duck-taped the panel filter to the top half and left it like that.
Didnt do anything for performance but the noise was great.

If youre just after noise then drill some holes in the standard airbox, below the filter on the side next to the wing.
Start with a few holes and try it untill you get the noise you want. Doesnt cost a thing.

[minime1275]

I've done the drilling the airbox trick on my mini, worked a treat! The duck-tape trick sounds tempting too! lol

[minime1275]

As far as performance filters are concerned, most people think they have little or no performance gains over the standard air filter.

So, assuming I was just after the induction noise and not a performance gain (tho I dont want a loss in performance), my options are:

Cone filters
K&N cone filter
Pipercross cone filter
Other cone filter

Replacement filter elements
K&N
Pipercross

Drilling holes in my standard airbox
Using standard filter element
Using K&N filter element

Obviously drilling the standard airbox and using the standard filter element is the cheapest route, but does it make a significant increase in induction roar (enough to drown out me tappets!)?

Does just replacing the standard element with a K&N element but keeping the standard airbox make an increase in induction noise?

Sorry for the chav-esque questions, but when an aftermarket mods gonna cost me up to 1/3 of the price of my car, I just wanna get some feedback from those who have tried it before I bite the bullet (im a tight arse)

Neil

[jmc330i]

Obviously drilling the standard airbox and using the standard filter element is the cheapest route, but does it make a significant increase in induction roar (enough to drown out me tappets!)?

Yes, there is quite a difference in the noise - depending on how many holes and how big.
You get a deep induction roar, where as my mates 205 gti with a K&N cone filter just sounds asthmatic.

Drill some holes along the bottom and the side nearest the wing and give it a try. Give the car a run and put the engine under some load and you will hear the difference.
Just keep going untill you get the noise you want. You can always patch it back up again.

A friend of mine cut a slot (about 2x6 inches) in the bottom of the airbox on his 320i. Fixed some gauze type stuff (I think he used a washing up scouring pad!) over the hole just to stop big bits of crap going in and that sounded great.

If youre just after the noise (like I would be) why spend money when you dont need to. Do the free stuff first and if you like it youre sorted.
Although replacing the panel filter is probably not a bad idea.