Just wondering if anyone has fitted a cone filter in there air box an kept the cold air feed the same? I have seen it done in the performance bmw mag on 3 series. I know it won't give power gains but surely its better than having it in all that hot air if you have an induction kit. Or has anyone made custom ram air feeds?
induction
- Thread starter wilko
- Start date
The air feed is actually quite good for the Z4. I have removed the restriction which is located behind the passenger side grill, and fitted a pipercross panel filter. Cone filters generally have better surface area, but without a box will draw in warm air from the engine. So best of both worlds is a decent panel filter imo 
chris said:The air feed is actually quite good for the Z4. I have removed the restriction which is located behind the passenger side grill, and fitted a pipercross panel filter. Cone filters generally have better surface area, but without a box will draw in warm air from the engine. So best of both worlds is a decent panel filter imo
What i was meaning was to run a cone filter within the box to keep the heat down, an have the cold air feed right to the cone, to make the induction kit work better if you have one
Yes but they were all new, and the whole point of using aftermarket filters is they don't clog up as much over time. Where as the paper ones are useless when dirty.
If anyone compared new panel filter of course they will be the same (ish) as the surface area is the same, and the filtration will be the same or similar.
If anyone compared new panel filter of course they will be the same (ish) as the surface area is the same, and the filtration will be the same or similar.
peddy said:Fair enough, but I guess you could change them at quicker intervals.
more importantly why do you think the aftermarket ones don't clog up? Where do you think that crap is going into instead?
Fair point, but ive never had any engine problems using aftermarket filters. And i want more air flow
And yes you can spend £15 every six months, but can you really be bothered when you can buy one that will do the job just as well
robbieleeson
Member
To put it quite simply you will get no extra performance from an aftermarket panel filter compared with a cleanish OEM filter. I work for Ford within the air induction department and deal with Mahle who produce the filter, a clean paper filter is surprisingly efficient and has next to no restriction associated at most engine speeds. If i remember correctly the only aftermarket filter which flows more is a K&N, however this does not capture the smaller dust particles that paper filters do. As somebody has already mentioned i would not go with an oil soaked filter so close to the MAF, just asking for trouble. People seem to forget that the vehicles calibration is also developed around one filter.
Interesting thread
( Ps welcome to the forum robbieleeson )
( Ps welcome to the forum robbieleeson )
lacroupade
Veteran
I can only speak from very long experience with K&N cone filters, having used them in the dirty shitty world of 4x4 motoring (on and off road) for the last 14 years in five different vehicles.
"They let oil through to the MAF" - thats a popular and recurring fallacy that mysteriously no-one ever manages to substantiate - its also bollocks. They use a simple thin spray oil which is dyed red so you can see it clearly, which you spray all over the surface of the filter after you've washed it. Its pre-treated for first use. You would have to soak the thing in a bath of oil for any to get into the airflow to the MAF. Even then, most MAF elements have a heating cycle when they are turned on or off (it varies) which burns off surface contamination. That very cycle of course contributes to the eventual demise of the MAF in itself. Bosch MAFs are renowned for frequent failure but they aren't very expensive. Hitachi MAFs (widely used by some manufacturers but wired differently, so not interchangeable) cost 6-7 times as much but are almost bombproof.
"They don't have any benefit! - also untrue, certainly in the vehicle applications I've used. A genuine and consistent 10% improvement in fuel consumption and a noticeable improvement in breathing has always been my experience. The only thing I would temper that comment with is that it depends very much on the OEM setup. If the OEM air intake setup is as efficient as it could possibly be, as opposed to being as efficient as it could be in the context of squeezing the bits into a confined space and taking air from somewhere convenient to the manufacturer, then it won't be as beneficial. So a properly tuned inlet won't benefit much. BUt how certain are we thats the case with the Zed? (Rhetorical question).
"They suck hot air into the engine" - not when you are moving above 15-20mph they dont.
"They let particles through that paper filters don't" - possibly true but its a bit of a "so what". I suggest you check the number of law suits against K&N, Pipercross and the like to see if that actually has ANY effect on the life of the engine. One of the vehicles I used it on still has it fitted with a new owner and it has now done 267,000 miles.......and thats in a high compression diesel that would be the first to fall over as a result of the effects of additional wear arising from particle contamination.
And lets not forget that these filters were primarily designed for, and cut their teeth in, motorsport.
So my advice is, if you want one, buy one and try it....it will either work or it won't, but for the £60-odd that a K&N induction kit costs, who cares?
PS just to respond to one point made by robbieleeson; w all know that vehicle "calibration" is a bit of a nonsense term.....in todays manufacturing climate, engines are "tuned" to work in as many places as possible, regardless of the often s**t quality of fuel in any given geography.....so calibration is a relative term and certainly not, IMHO, detailed enough to be negatively impacted by a change of air filter. But thats just my humble opinion.....
"They let oil through to the MAF" - thats a popular and recurring fallacy that mysteriously no-one ever manages to substantiate - its also bollocks. They use a simple thin spray oil which is dyed red so you can see it clearly, which you spray all over the surface of the filter after you've washed it. Its pre-treated for first use. You would have to soak the thing in a bath of oil for any to get into the airflow to the MAF. Even then, most MAF elements have a heating cycle when they are turned on or off (it varies) which burns off surface contamination. That very cycle of course contributes to the eventual demise of the MAF in itself. Bosch MAFs are renowned for frequent failure but they aren't very expensive. Hitachi MAFs (widely used by some manufacturers but wired differently, so not interchangeable) cost 6-7 times as much but are almost bombproof.
"They don't have any benefit! - also untrue, certainly in the vehicle applications I've used. A genuine and consistent 10% improvement in fuel consumption and a noticeable improvement in breathing has always been my experience. The only thing I would temper that comment with is that it depends very much on the OEM setup. If the OEM air intake setup is as efficient as it could possibly be, as opposed to being as efficient as it could be in the context of squeezing the bits into a confined space and taking air from somewhere convenient to the manufacturer, then it won't be as beneficial. So a properly tuned inlet won't benefit much. BUt how certain are we thats the case with the Zed? (Rhetorical question).
"They suck hot air into the engine" - not when you are moving above 15-20mph they dont.
"They let particles through that paper filters don't" - possibly true but its a bit of a "so what". I suggest you check the number of law suits against K&N, Pipercross and the like to see if that actually has ANY effect on the life of the engine. One of the vehicles I used it on still has it fitted with a new owner and it has now done 267,000 miles.......and thats in a high compression diesel that would be the first to fall over as a result of the effects of additional wear arising from particle contamination.
And lets not forget that these filters were primarily designed for, and cut their teeth in, motorsport.
So my advice is, if you want one, buy one and try it....it will either work or it won't, but for the £60-odd that a K&N induction kit costs, who cares?
PS just to respond to one point made by robbieleeson; w all know that vehicle "calibration" is a bit of a nonsense term.....in todays manufacturing climate, engines are "tuned" to work in as many places as possible, regardless of the often s**t quality of fuel in any given geography.....so calibration is a relative term and certainly not, IMHO, detailed enough to be negatively impacted by a change of air filter. But thats just my humble opinion.....
Very interesting thread,has anyone put the K&N straight replacement air filter on,as opposed to an induction kit,if so would like your comments please as i am contemplating getting one,retail at about £36- as opposed to £20-for the standard one.