to filter or not to filter?

[Polisiehond]

I want to get a aftermarket filter like K&N or something to give the 540i a bit more grunt...it is VERY quiet even when I stomp on it.
I was thinking a duel-cone filter as I am sure that the V8 sucks in a lot of air.

Any thoughts on this?

 

[STREETRACER]

V8 = hoover x2 LOL.. I would stick to stock airbox with replacement filter though! had many trial and errors with open cone and CIA's and best all rounder performance is stock airbox with KnN or BMC panel replacement filter!

 

[P1000]

With K&N the oil will foul up your MAF

 

[STREETRACER]

bud then you oiling yours to much! i have mine in for 3 years in the M3 and no MAF problems! I do how ever clean my MAF with every oil service interval but that is a normality!

 

[rick540]

The stock airbox contains two Helmholtz resonators, very clever things that act like an air pump at certain frequencies.

I have always maintained that BMW engineers know what they are doing from the start and that aftermarket filters are for Golfs, Opels and stuff.

 

[E39 Ian]

+1

I have tried to run without airfilter and also a maximising airfilter - the car ran like sh1t, farting and backfiring, cutting out - I would not do anything at the airbox

Rather remove your cats and investigate further exhaust mods for a better grunt

rick540 would be able to advise you

 

[Bossman]

The stock airbox contains two Helmholtz resonators, very clever things that act like an air pump at certain frequencies.

I have always maintained that BMW engineers know what they are doing from the start and that aftermarket filters are for Golfs, Opels and stuff.

You are right , those aftermarket stuff do not work!!, the stock boxes are designed properly, by proper engineering principals, I hate these know better know all wannaby's that allways thinks that some cone is better, I actually proved some of this by doing air pressure tests with my rear mounted turbo E46 325i in another thread.

 

[conquest]

agreed...

found a K&N panel filter in my airbox and immediately fitted a new standard unit. didnt notice any performance decrease at all...

although if you want to try it out for yourself... i still have the panel filter in a box rolling around in the boot... you are welcome to it...

 

[STREETRACER]

The stock airbox contains two Helmholtz resonators, very clever things that act like an air pump at certain frequencies.

I have always maintained that BMW engineers know what they are doing from the start and that aftermarket filters are for Golfs, Opels and stuff.

You are right , those aftermarket stuff do not work!!, the stock boxes are designed properly, by proper engineering principals, I hate these know better know all wannaby's that allways thinks that some cone is better, I actually proved some of this by doing air pressure tests with my rear mounted turbo E46 325i in another thread.

Bud in that case im one of the know it all! :thumbsup:
The right after market filters do work! im a very active racer and have track tested, Vbox tested and Dyno tested all forms of inductions! and the OEM filter - BMC pannel filter swap makes a considerable difference on our dissplacement engines!
You are welcome to come around and ill prove it!

 

[Raybimmer]

Simple test : measure time in 3rd or 4 th gear from 1500 revs to say 6000 revs with each filter on same day.:thumbsup:
The increased air flow should give you a power increase of a few watts and cut your time by milliseconds . :clap::clap:

 

[Polisiehond]

Thanks for the tips!
I think I will stick with the stock filter then...:thumbsup:

 

[STREETRACER]

we gained 4wkw on a E36 325i with a filter alone and 7wkw on nish 3.2 M3. and that you do feel!