325i cne filter? whats so wrong with them?

Mon Nov 12, 2007 9:09 pm

iv got a kn cone filter on my 325i sport as well as a superchips super chip and a straight through sebring exhaust and the cars rapid. will changing the cone filter make it quicker or slower? whats the best filter? cheers

Mon Nov 12, 2007 9:12 pm

It will be better with a heatshield around it,but there is nothing wrong with induction kits,the standard airbox is a sh1te design anyway,I put a 325i airbox in the bin this afternoon after tripping over it one too many times in the garage!

Mon Nov 12, 2007 9:15 pm

schuey wrote:It will be better with a heatshield around it,but there is nothing wrong with induction kits,the standard airbox is a sh1te design anyway,I put a 325i airbox in the bin this afternoon after tripping over it one too many times in the garage!

every time i get under the engine i lean on the filter by mistake and knock it off! it is the most anoying and fidily thing to get back on. it drives me mental!!!!!! have u found this or am i just impatient!

Mon Nov 12, 2007 9:15 pm

The cone filters normally sit just above the alternator, the alternator has fins attached to it to dissapate heat away, K&N's suck in this ovely hot air and general engine heat thus making acceleration and performance poor, never mind fuel economy! Mine was in for about 6 months then I though hang on a minute, Have put the standard airbox and K&N panel filter in and it has made alot of difference.

Mon Nov 12, 2007 9:16 pm

uzdubmwe30 wrote:The cone filters normally sit just above the alternator, the alternator has fins attached to it to dissapate heat away, K&N's suck in this ovely hot air and general engine heat thus making acceleration and performance poor, never mind fuel economy! Mine was in for about 6 months then I though hang on a minute, Have put the standard airbox and K&N panel filter in and it has made alot of difference.

mine does drink like a fish. will a heat shield help?

Mon Nov 12, 2007 9:20 pm

Mike-tec wrote:iv got a kn cone filter on my 325i sport as well as a superchips super chip and a straight through sebring exhaust and the cars rapid. will changing the cone filter make it quicker or slower? whats the best filter? cheers

many on here will tell you that bmw designed the bestest ever standard filter that cant be bettered by god himself even though 20 years of progress has been and gone. simply clean out your k+n and fit a heatshield around it. job done.

Mon Nov 12, 2007 9:23 pm

It's an E30 mate they drink wether you've got 2.7 or a 1.6, mine uses fuel when it's not running! Heat shield will help, but the standard airbox design with a panel filter is pretty much flawless, has it's own heat shield then,

Mon Nov 12, 2007 9:31 pm

k&n's give a good sound and will only loose you a couple of bhp if that

Mon Nov 12, 2007 9:34 pm

schuey wrote:It will be better with a heatshield around it,but there is nothing wrong with induction kits,the standard airbox is a sh1te design anyway

So BMW spent thousands developing it and it's shit?

I would like to see a gain from a K&N filter?

Mon Nov 12, 2007 9:35 pm

schuey wrote:i put a 325i airbox in the bin this afternoon after tripping over it one too many times in the garage!

you should have attached the rest of the engine to it and stuck in in your 1.8

Tue Nov 13, 2007 2:04 am

maxfield wrote:
schuey wrote:It will be better with a heatshield around it,but there is nothing wrong with induction kits,the standard airbox is a sh1te design anyway
So BMW spent thousands developing it and it's shit?

I would like to see a gain from a K&N filter?

They developed it for a purpose and to maximse hp and induction noise was not the goal there are tradeoffs to consider.

The K&N panel filter showed gains over new paper........never seen a test from a cone variety though.

It is important to limit the IAT for many reasons so if you can do this while limiting how convuluted the path for the air is you'd be onto a winner. Its unlikely to be more than a few % though especially if everything downstream is unchanged

Tue Nov 13, 2007 6:57 am

The heat makes feck all difference at speed. Check Sals dyno results for the car he tuned with one. Managed 10bhp over stock with a magic chip.

It will absorb heat while at a standstill, but once under speed, the engine bay temperature drops to ambient.

K&N filters are a particulalry poor example for cone filter. Universal fitting, weak brackets etc. I replaced mine with a Pipercross one, machines aluminium. Much better!

http://www.e30zone.net/modules.php?name ... ic&t=84366

Note comment about fan being on...

Tue Nov 13, 2007 8:45 pm

The only car I have ever noticed a gain on from an induction kit is a 1.4 golf.

I think this is because it was a small uncomplicated engine in a big engine bay, i had the filter well away from the engine and a decent cold air feed to it.
I also put a cone filter on a mazda 323f v6 i had, it blunted the performance, especially top end but the fuel economy was the worst thing, completely ruined.
I haven't even bothered fitting a cone filter or even an aftermarket air filter to my 325, I can't see it really gaining, where do you get the cold air? Same problem I had with the mazda. And if you were just after induction roar I personally don't think there's much difference in induction noise on an m20 with a cone.

Tue Nov 13, 2007 8:54 pm

Pretty sure some recent issue of some Bmw mag (Performance Bmw or one of those) tested a 325i with a pipercross induction kit and it gained 12 bhp when compared to a normal paper filter and airbox?

Tue Nov 13, 2007 8:58 pm

Cones are shite, if your going to do anything at all at least go for a panel, but then these dont filter as good as a paper filter plus a cone is all noise no result!!!
Great if your a boy racer!!!

Tue Nov 13, 2007 11:06 pm

maxfield wrote:
schuey wrote:It will be better with a heatshield around it,but there is nothing wrong with induction kits,the standard airbox is a sh1te design anyway
So BMW spent thousands developing it and it's shit?

I would like to see a gain from a K&N filter?

An early edition of i think Performance BMW at bexleys did a cone filter test and paper element test. Everything bettered the standard filter, but the K&N came out top with IIRC 5-6bhp and a couple ft-lbs torque.

People can interpret these anyway they want but bexleys are a know source for providiing consitent figures.

At the end of the day you would barely notice a few bhp - if it sounds better, doesnt feel slower then who gives a turkey right?

Tue Nov 13, 2007 11:14 pm

fuzzy wrote:
schuey wrote:i put a 325i airbox in the bin this afternoon after tripping over it one too many times in the garage!
you should have attached the rest of the engine to it and stuck in in your 1.8

Tue Nov 13, 2007 11:20 pm

Have to agree about heat issues , When sittin in traffic then pulling away sometimes seems flat , Have since removed a headlight and done a cold feedpipe into the end on the cone , Noticeable difference when driving at night and booting it , Slightly more responsive and revs smoother , Have no heat shield either , Might go down the lines of a panel filter next

Wed Nov 14, 2007 12:31 am

An early edition of i think Performance BMW at bexleys did a cone filter test and paper element test. Everything bettered the standard filter, but the K&N came out top with IIRC 5-6bhp and a couple ft-lbs torque.

Yeah I saw the same article. Definitely said they got a power increase using a K&N.

Wed Nov 14, 2007 9:58 am

the 325 touring in total Bmw also showed gains with a cone filter I am tempted to fit one myself but would like conclusive proof eg a dyno run with the itg filter. At the moment i have a k+n panel filter which does give better throttle response than the standard air filter. heats not an issue for me as i don't really drive in traffic sod having an e30 in a city.

Wed Nov 14, 2007 10:59 am

Geoff wrote: At the end of the day you would barely notice a few bhp - if it sounds better, doesnt feel slower then who gives a turkey right?

exactly

Wed Nov 14, 2007 12:08 pm

mines got a pipercross cone filter on it... ive been wondering if it is the cause of loads of problems because i bought the car like it.... how much is an airbox gonna cost and were from? i wanna take it off it looks chavvy anyway

Wed Nov 14, 2007 5:24 pm

When i first got my 325i.....The first mod i did was to bin the K&N cone and refit the standard airbox/filter setup......

Thu Jan 29, 2009 6:51 pm

Some pudding has decided to let his pet mice live in the airbox in my car's past, it would seem.

There are more holes in it than your local golf course!

So this in mind, do I use my BMC Carbon Dynamics Airbox, or do I repair the standard airbox with some gaffa tape?

Thu Jan 29, 2009 6:58 pm

2007 called, they want their thread back

If you want noise and powaaaah just take it all off, who needs to filter air anyway when you can have all that noise... It's not like dust and crap effects your engine anyway...

Thu Jan 29, 2009 7:11 pm

If Brian moooore says the standard set-up is best then that's good enough for me!

Thu Jan 29, 2009 7:32 pm

datourer wrote:If Brian moooore says the standard set-up is best then that's good enough for me!

What if he told you playing 'hide the sausage' with the boys was a good idea?

Thu Jan 29, 2009 7:34 pm

Joeey wrote:
datourer wrote:If Brian moooore says the standard set-up is best then that's good enough for me!
What if he told you playing 'hide the sausage' with the boys was a good idea?

Good reply

Thu Jan 29, 2009 7:35 pm

ive got the piper cross filter i took off my old 4 door which was on it wheni bought it. been tempted to fit it to my sport

Thu Jan 29, 2009 7:35 pm

GrindCulture wrote:2007 called, they want their thread back

If you want noise and powaaaah just take it all off, who needs to filter air anyway when you can have all that noise... It's not like dust and crap effects your engine anyway...

Oops!

I've got that many tabs open with E30Zone stuff in all of them, I didn't check dates, my bad.

Twas a search result evidentily!

I'm not after noise, i'm after which will allow my engine to run correctly and I just so happened to have the CDA box sat around in the garage as the alternative to the standard box! I haven't tried it with anything but standard as yet.