K&N filters, worth it?

[Seany88]

Just interested in people's opinions of these, more in terms of cost-effectiveness rather than seeking performance as they're supposed to last forever! But is the filtration as good/better than OEM?

[hongkongfooi]

Absolutely.....in my opinion the best filters on the market. Better intake sound, million mile
warranty......wheres the catch? only in the initial cost.

[sleep envy]

Seany88 said:

But is the filtration as good/better than OEM?

I put a dollop of grease on the intake just after the K&N filter of a car I used to have and after a few weeks it caught loads of dust and grit. Tried the same with a new OEM filter and the grease had collected far less particulates.

Although they sound better and release a few horses IMO it's not worth the risk of damage to the engine.

[allnighter]

sleep envy said:

Seany88 said:

But is the filtration as good/better than OEM?

I put a dollop of grease on the intake just after the K&N filter of a car I used to have and after a few weeks it caught loads of dust and grit. Tried the same with a new OEM filter and the grease had collected far less particulates.

Although they sound better and release a few horses IMO it's not worth the risk of damage to the engine.

Now you tell me!
I had a K&N filter for the best part of 3 years in my 6 series.
Interesting way of testing though.Glad the dollop of grease didn't end up in the intake under hard acceleration.

[daver]

Sleepy - isn't the gauze on K&N's supposed to be treated with an oil of some description to aid in trapping particles? Was yours?

I've never used one but have considered it. Never heard anyone mention them letting loads of crap through before though. Just curious.

[sleep envy]

Yep, it came in a plastic bag and was pre-oiled.

Was just curious to see how a filter can claim to increase ponies. This was just *my* understanding using only a K&N product and a simple test - don't have any experience of other brands.

[G-Rich]

Simple tests will show that a K&N filtration is worse (but not necessarily significantly) than standard paper filters. Logically this makes sense - the extra air has to get in somehow!

This being said, I only think I ever heard of one engine taking serious damage that *may* have been attributed to an aftermarket filter (but who knows if it was looked after and maintained as per the manufacturers recommendation). I am sure there are millions are satisfied K&N customers... ask any Nova driver!!

I think a bigger issue is to ensure the filter is properly shielded from the heat in the engine bay and as near to the direct airflow as possible. Otherwise you will just end up sucking in hot air when stationary causing lumpy idles and other issues.

Cheers
Rich

[Garrett]

You won't see any performance increase, but your car will almost certainly sound faster.

As mentionned above, these filters can suck hotter air into the engine, so watch out for that.

[Seany88]

Sleepy was yours a replacement panel filter or the cone version?

I'm assuming that if you had a K&N on the car and the engine went, it wouldn't be covered under warranty etc then?

Think i'll stick to OEM.

[sleep envy]

Seany88 said:

Sleepy was yours a replacement panel filter or the cone version?

I'm assuming that if you had a K&N on the car and the engine went, it wouldn't be covered under warranty etc then?

Think i'll stick to OEM.

K&N panel - the engine didn't break, I just noticed it was letting though more particulates than the OEM panel filter which is why I switched back.

[off_again]

Be warned though, most modern BMW's have a decent intake system anyway. On cars which have very restrictive intakes (Jeeps for example) you get good gains and performance. But on modern engined BMW's the difference is negligable. Better sound fine, but performance gains - probably not..... unless there is a change to the ECU etc where a better flow of air is required....

[swansea v6]

Get yourself to www.e36coupe.com and have a look for either a Gruppe M crbon fibre induction kit, of a dave f fit. Thedave f is made by one of the forum members, it is an oversize k+n filter shielded from the engine bay by a very well made heatshield, and has seen gains of 13bhp on an me.......... worth investigating