Anyone have K&N air filter on your car?

[Rick L]

Does anyone have K&N air filter in your car? I'm thinking of getting stock replacement K&N air filter but wondering if that would improve performance at all... I noticed a difference in my friend's Porsche 928 S4 but in a 525i with 2.5L engine????

[Guelphguy]

I do on my 90 535i, did I notice a difference no? I got it cheaper than a stock replacement if you can believe that, so likely next year, I will just go back to stock as I do wonder about the possible increased "grit" intake that they talk about so much with these...not worth the risk if you ask me....
:p

[Rick L]

I don't understand when people say, "not worth the risk"... Isn't K&N, in fact, filter BETTER than paper filters because of the oil on the filter. I have seen many articles that states that it does better job of filtering than paper filter. However, performance varies to none... :(



I do on my 90 535i, did I notice a difference no? I got it cheaper than a stock replacement if you can believe that, so likely next year, I will just go back to stock as I do wonder about the possible increased "grit" intake that they talk about so much with these...not worth the risk if you ask me....
:p

[bahnstormer]

more air = bigger holes = more dirt
its simple.

[632 Regal]

Rick calm down some....stock is good. If it feeds a 540 im sure its good and plenty for a 525.

[infinity5]

i read a rather long article/experminet at bobistheoilguy.com comparing a whole lot of filter types including K&N. his results did show there was a difference in filtering, but it was very negligible. the argument is that over time that small percentage adds up to real wear and tear. *shrug*. i don't think, in everyday driving, its really a huge issue. your engine isn't going to fail becuae you let in 1% more "dirt" over the life of the engine. not to mention not everyhting thats making it past the fitler is sand or grit. most of its probably pollen, dust, and air pollution, which i doubt would create any wear to speak of in something as tough and metallic as our engines.

just go for it and if you feel a gain come back and tell us. change your oil often and use a good brand if you get worried about the filtering capabilities.

there was also some debate about how quickly K&N filters loose their free-flowing properties when dirty.... never read much about that, but it might be an issue.

[Jon K]

Yeah but the thing no one thinks about is the fact that you cannot put a factory filter on a modified induction car. For instance, VW/Audi use Fram/Meyhle/Bosch paper filters on their factory FI setups... but like i said you can't (or RARELY) use a factory airbox/paper filter on an aftermarket forced induction system... so do you honestly think filter companies are going to say "well nothing beats paper filters, oh well, high performance seekers are going to just suck dirt up..."?

[Dash01]

One thing you might want to consider is the stock filter, even though perhaps more restrictive (better filtration) per square inch than K&N, has a lot more square inches to work with. So, even at the breathing rate of our engines at max power, the stock filter is large enough to have little or no practical restriction problem, while probably keeping out more crud than K&N. What say you?

[Jon K]

Stock airfilter will not fit with one of these in place :D

http://e34.digital7.com/Cars/IMG_2932.JPG

[Alexlind123]

One thing you might want to consider is the stock filter, even though perhaps more restrictive (better filtration) per square inch than K&N, has a lot more square inches to work with. So, even at the breathing rate of our engines at max power, the stock filter is large enough to have little or no practical restriction problem, while probably keeping out more crud than K&N. What say you?

More restrictive does not necessarily mean more filtration, it is probably just less efficient. Althought i dont have any first hand knowledge of k&n intakes or filters being added to BMWs, i would guess that a k&n intake and cone filter with a heat shield would almost certainly improve throttle reponse and horsepower and the same would be true of just a filter but to a lesser degree.

[Anthony (M5 in Calgary)]

Think about it. The engineers in Munich thought the filter was big enough for a 3.6-3.8L engine pulling 7000+ RPM.

There's also the issue if your car has a hot wire/film MAF. Oil from the oil/gauze filters if overdone during cleaning will contaminate the sensor.

Just use the OE paper filter.

Anthony

[granit_silber]

Does anyone have K&N air filter in your car? I'm thinking of getting stock replacement K&N air filter but wondering if that would improve performance at all... I noticed a difference in my friend's Porsche 928 S4 but in a 525i with 2.5L engine????


ummm...since no one has thrown this one up yet.

http://www.bmwe34.net/e34main/upgrade/Air_filter.htm

I really think it's six of one and a half a dozen of the other. Just make sure to take care of the filter (recharge it) as specified and not do any driving in the Sahara. :)

-ashley

ps plus you'll get that cool intake sound

[granit_silber]

Jon,

Did I read somewhere that your e34 is a turbo'd 525 or was I just dreaming?

If it is did you ever post a write on the turbo-ing process? (i.e. what had to go, pro's, con's)

-ashley

[Jon K]

Jon,

Did I read somewhere that your e34 is a turbo'd 525 or was I just dreaming?

If it is did you ever post a write on the turbo-ing process? (i.e. what had to go, pro's, con's)

-ashley

You probably read that I am supercharging my 525. I probably did argue pros and cons of supercharging vs turbo.

[granit_silber]

You probably read that I am supercharging my 525. I probably did argue pros and cons of supercharging vs turbo.


Isn't your 525 turbo'd? If not, whose car (with the boost gauge) was in the video you made in front of the university police station?

Sorry, if I'm confused *yawn* need sleep.
-ashley

[brodee]

The other thing to think about when someone tells you they noticed a big difference in putting in a K&N is that they probably replaced a dirty filter. Changing from a dirty to a clean of the same brand would most likely net some better "feel".

I used to hear the same thing when I worked in a parts store and people would buy spark plugs. They would get splitfires or something like that and come back and tell me how the car was running so much better with them, not taking into account that the old plugs were shot and any new plug would make it run better.

[Jon K]

Isn't your 525 turbo'd? If not, whose car (with the boost gauge) was in the video you made in front of the university police station?

Sorry, if I'm confused *yawn* need sleep.
-ashley



That was my car, boost gauge is in for the supercharger :)

[granit_silber]

That was my car, boost gauge is in for the supercharger :)
my bad.

[632 Regal]

wheres the supercharger pics?

[rnrn]

Lots of Answers (http://n2performance.com/customer/pages.php?pageid=66)

And there are several other manufacturers of peformance filters out there. If you were really freaked out about dirt or sand getting in just get an oil bypass system or change it religiously. The sizes of particles they are talking about would not damage your engine unless A) you never cleaned your filter and B) you never changed your oil or filter.

[Alexlind123]

That was my car, boost gauge is in for the supercharger :)

Could you post a link to that video?

[niall]

What motor is in your X300 jag Rick?

someone said more air = bigger holes, less filtration.
not true, i have seen dyno testing on a small block chev,
which showed that a k&n filter flows more CFM than no filter
at all, and a old model truck filter flowed more than that, and it
was paper, so no more air does not mean bigger holes,

also i have seen a ford focus on a rolling road and
the gys installed a k and n filter and it gained 1 to 1.5 bhp,
so that is the kind of "performance gain" you should expect
some people would say its insignificant, some would say
every little helps, make your own mind up

[Rick L]

The JAG X300 has a 4.0 liter straight 6. Very reliable 6 unlike V8 with Nikasil engine. Jaguar had the same problem as the BMW with Nikasil engine. My father's friend had one with Nikasil that went bad with only 36k miles. It was covered under warranty but you got to wonder...

http://home.comcast.net/~jungerishere/MyJaguar.JPG

I have heard many different stories and opinions about K&N filters. I definitely heard and felt the difference in my friend's 928 S4 and the stock filter is NOT dirty (it is brand new). When he cleans the K&N filter, he dry the filter for overnight and use stock as backup. I used to think K&N filter was just the hype but made a difference in a Porsche... However, I'm not sure about the Bimmer with small 6. Maybe, I'll give it a try... I already order one for the Maserati. Maybe, high-flow-air might help the twin-turbo-charged car! :D

http://home.comcast.net/~jungerishere/Maser_Engine.JPG





What motor is in your X300 jag Rick?

someone said more air = bigger holes, less filtration.
not true, i have seen dyno testing on a small block chev,
which showed that a k&n filter flows more CFM than no filter
at all, and a old model truck filter flowed more than that, and it
was paper, so no more air does not mean bigger holes,

also i have seen a ford focus on a rolling road and
the gys installed a k and n filter and it gained 1 to 1.5 bhp,
so that is the kind of "performance gain" you should expect
some people would say its insignificant, some would say
every little helps, make your own mind up

[632 Regal]

I'll let you guys beat this one up... My take on any gains are that the filter stops waves of air, smoothing them to a sinle even flow of air. Thats a standard of any intake system which BMW has covered well. A smooth intake rush is much better than a rough wave such as a hood scoop with no filter element to smooth things out.

Also I want a ride in Jons supercharged car when its done.

[Bimminator]

I'll let you guys beat this one up... My take on any gains are that the filter stops waves of air, smoothing them to a sinle even flow of air. Thats a standard of any intake system which BMW has covered well. A smooth intake rush is much better than a rough wave such as a hood scoop with no filter element to smooth things out.

Also I want a ride in Jons supercharged car when its done.


What do you thint about those gadgets available now thatfit in the air intake right aftr the air filter that forces the "smooth air" into a vortex. I think they are called Turbonators. They claim to add some horse power for under $100 ?

Bimminator

[Jon K]

I'll let you guys beat this one up... My take on any gains are that the filter stops waves of air, smoothing them to a sinle even flow of air. Thats a standard of any intake system which BMW has covered well. A smooth intake rush is much better than a rough wave such as a hood scoop with no filter element to smooth things out.

Also I want a ride in Jons supercharged car when its done.


No problem Jeff.



I once watched a biturbo maserati go up in flames :D

[niall]

i was in a xjr v8 at work a few weeks ago,
i gotta tell you they go hard.

the 4.0 xk motors are good, very reliable and strond,
also they dont suffer from the plastic impellor issue

[niall]

what is the predicted output at the crank for the blown 2.5i setup?

[Rick L]

Now, that's not very nice. Any car can go up in flames if not taken care of. I was hoping to get some additional answers from Bimmer guys but don't bash my opinion or my cars... :(



No problem Jeff.



I once watched a biturbo maserati go up in flames :D