The best Air Filter?

Hi all!

What do you think is the best air filter for an E39 1999 520i?
I was browsing at K&M website and they only have the "exterior" with no
air box model (57i Induction Kit - part nr 57-0439). Is this exteriour
model too noisy?

Any sugestions?

Are there any other good web sites in Europe, besides eurocarparts.com, to
buy from?

Thanks!

Vasco

How do you define "best"? Its hard to beat the factory cold-air setup.
The K&N "exterior" one with no airbox will only suck in hot air and
give you LESS performance. You gas mileage will go down and you will be
slower....

"vricardo" > wrote in message
lkaboutautos.com...
> Hi all!
>
> What do you think is the best air filter for an E39 1999 520i?
> I was browsing at K&M website and they only have the "exterior" with no
> air box model (57i Induction Kit - part nr 57-0439). Is this exteriour
> model too noisy?
>
> Any sugestions?
>
> Are there any other good web sites in Europe, besides eurocarparts.com, to
> buy from?
>
> Thanks!
>
> Vasco

The "best" one is the one you already have, just put a clean paper filter in
it. It is an excellent balance between filtering efficiency and reducing
intake restriction and was designed by a vast team of highly skilled
engineers at BMW. What makes people think that some jamoke designing CAIs
in his basement will make a "better" design?

If you search around enough you will see that there is no proof of increased
horsepower from any filter that also actually filters the air. Some of the
less restrictive "filtering" systems have the potential to increase
horsepower on an engine that has other mods that require it to breathe
faster, but certainly not for a bone stock engine. Plus, those less
restrictive filters are less efficient at removing particulate crap from the
air, which afterall is the whole point, isn't it? Not to metion the
decreased oxygen charge due to the increased air temperatuire of the air
being sucked out of the engine compartment on the majority of these
fly-by-night affairs.

I would thing that one of the ridiculous throttle body spacers would be a
better investment than one of these filters. It wouldn't give you *any*
increase in horsepower, but it would cost about 1/2 as much and would not
cause any increase in the engine wear either.

Otherwise, just run an open intake (no filter) piped to the front grille and
get the most horsepower possible for the short time before the rebuild is
required.

YMMV, ...but not much ;-)
-Fred W

-Fred W

Unless you are racing, the stock air filter is fine.

K&Ns only advantage is that you never have to replace it, but it has
overhead that makes replacing the air filter a tiny fraction of the cost of
ownership. I say you should get another stock filter three or four times a
year, and move on.



"vricardo" > wrote in message
lkaboutautos.com...
> Hi all!
>
> What do you think is the best air filter for an E39 1999 520i?
> I was browsing at K&M website and they only have the "exterior" with no
> air box model (57i Induction Kit - part nr 57-0439). Is this exteriour
> model too noisy?
>
> Any sugestions?
>
> Are there any other good web sites in Europe, besides eurocarparts.com, to
> buy from?
>
> Thanks!
>
> Vasco
>
>
>

Jeff states:

<K&Ns only advantage is that you never have to replace it, but it has
overhead that makes replacing the air filter a tiny fraction of the
cost of ownership.>

This is true in part in that you really don't have to replace a K&N
filter. However, you do need to clean and oil it and that in itself can
be a problem. I believe it was Jim Conforti of "Jim C chip" fame, who
stated that K&N filters actually allow more dirt into the engine and
thus, is not good for your car. Of course, K&N will dispute that. As
Jeff stated, change your stock filter more and move on....

bfd wrote:
> Jeff states:
>
> <K&Ns only advantage is that you never have to replace it, but it has
> overhead that makes replacing the air filter a tiny fraction of the
> cost of ownership.>
>
> This is true in part in that you really don't have to replace a K&N
> filter. However, you do need to clean and oil it and that in itself
> can be a problem. I believe it was Jim Conforti of "Jim C chip" fame,
> who stated that K&N filters actually allow more dirt into the engine
> and thus, is not good for your car. Of course, K&N will dispute that.
> As Jeff stated, change your stock filter more and move on....

K&N filters do indeed let more dirt in. I've had oil analysis done which proves
it. If you're at all concerned about engine life, stick to the stock paper
filters.

The real advantage of K&N filters was in off road racing. They still flow well
when dirty, and can be cleaned in the field if necessary. But for road cars
there's no reason to use them, whatever their popularity and marketing may
suggest.

Matt O.

"bfd" > wrote in message
oups.com...
> Jeff states:
>
> <K&Ns only advantage is that you never have to replace it, but it has
> overhead that makes replacing the air filter a tiny fraction of the
> cost of ownership.>
>
> This is true in part in that you really don't have to replace a K&N
> filter. However, you do need to clean and oil it and that in itself can
> be a problem. I believe it was Jim Conforti of "Jim C chip" fame, who
> stated that K&N filters actually allow more dirt into the engine and
> thus, is not good for your car. Of course, K&N will dispute that. As
> Jeff stated, change your stock filter more and move on....
>

That is the overhead.

Thanks guys!

Vasco

"Matt O'Toole" > wrote in message
...

> The real advantage of K&N filters was in off road racing. They still flow
well
> when dirty, and can be cleaned in the field if necessary.

The implication is that off-road racers rebuild engines after every race so
the added particulate ingestion isn't a matter of concern?

"Jeff Strickland" > wrote in
:

> Unless you are racing, the stock air filter is fine.
>
> K&Ns only advantage is that you never have to replace it, but it has
> overhead that makes replacing the air filter a tiny fraction of the
> cost of ownership. I say you should get another stock filter three or
> four times a year, and move on.
>
>

I put one on when working out a problem with my kugelfischer -- warm up
transmitter was going south. With the K & N you didn't have to remove the
damn air cleaner every time you needed to adjust something -- This summer
i'll put the stock air cleaner back on to counter the dusty roads.