Best Aftermarket Air Filter For Focus Mk2.5

[PaulR93]

I have a 1.6 10 plate Zetec s and looking at the Cotton Green Filter but just wanting to know what fellow Zetec S owners have in their car and what they recommend

Thanks

[higgsy]

K&n panel on mine. Had a one on every car I own.

[theduke]

K&n panel on mine. Had a one on every car I own.

Me too, Although green ones seem to be recommended on this forum cant see there being any noticable difference between the two

[Lenny]

I have a 1.6 10 plate Zetec s and looking at the Cotton Green Filter but just wanting to know what fellow Zetec S owners have in their car and what they recommend

Thanks

As you probability know already; I've got the green cotton performance induction filter fitted,

But the price of a K&N57s has more than halved in the past year so I'm tempted to invest in one of those.

http://www.ebay.co.uk/itm/K-N-57S-4000-Performance-Intake-Kit-FORD-FOCUS-II-RS-/271238138352?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item3f270d89f0

[FOCA]

Me too, Although green ones seem to be recommended on this forum cant see there being any noticable difference between the two

They are both oiled cotton types, that can contaminate MAFs (especially if they are over-oiled by the owner after cleaning) and can allow small particles of dust into the engine (not 100% efficient at filtering) - moreso when the filter is new and it has not built up a layer of dust, then it filters more particles

The Green cotton filter has a better bonding process/ design than the K&N that allows a larger surface area (more air/ less restriction) and the green colour allows you to see when the filter needs cleaned,(the K&Ns are black and can get filthy and can get left on cars for years as there owners think they will last forever) - the K&Ns tend to be cheaper, though

On some cars switching to a performance fillter makes is no difference at all (often, the filter is not the bit "holding the engine back" - as the filter may have a large surface area - ie-the size of a manhole cover - and the main restriction is elsewhere in the induction system) - so adding a K&N is just allowing more dust particles into the engine with no gain

On some cars there is no actual power gain but an improvement in throttle response

On some there is a slight increase in HP at high revs (typically 1 to 2 HP) - usually on NA

On some there is no power improvement in the band but a slight improvement in throttle response and reduction in lag and a little more power at very low revs before the turbo spools up (on a turbo, petrol or diesel)

Ive done a lot of research on this and one of these days i will publish the findings (when i get round to it )

Im not a big fan and i use a cheap pattern paper filter on mine and change it every 6 months - a new paper filter will outperform (for airflow) an old, clogged "performance" one and filters dust/ contaminants much better - and my engine produces 160+ HP (independantly dyno tested) from the 113HP stock with the paper filter fitted

[PaulR93]

Thanks for your feedback. I read a review (Attached below) Where foam filters perform better then cotton ones such as pipercross filters has anybody used one of them?

http://m.fastcar.co.uk/2012/05/04/performance-car-air-filter-test/

[theduke]

can i say ive never had a maf fail on any of my cars including an astra which usually eat mafs for breakfast using a k+n panel, bet my maf fails in the next few months now ive said that lol

[higgsy]

can i say ive never had a maf fail on any of my cars including an astra which usually eat mafs for breakfast using a k+n panel, bet my maf fails in the next few months now ive said that lol

Same here and I have washed and re-oiled many times. Just need to be fairly liberal with the oil. I told a lie - on an old punto I had a green induction kit. But every other car has had a k&n panel lol. I just tend to wash and re-oil every couple of years which for me is 15-20k miles but check it every time I do a service. I think its easy enough to tell when its dirty, cones get alot dirtier than panels as I seem to remember that green induction kit was black after a few months

[FOCA]

Thanks for your feedback. I read a review (Attached below) Where foam filters perform better then cotton ones such as pipercross filters has anybody used one of them?

http://m.fastcar.co.uk/2012/05/04/performance-car-air-filter-test/

Yes, i tried a massive pipercross rally car filter on my race car but it restricted the flow so much it would not rev at the top end (so did a very large K&N cone filter) so i went back to an open bellmouth

The reveiw is no good because it measures the filters away from actual engines and does not take things like heatsoak, and the intake resonant frequency/ tuned length

With the Fiesta ST150 used - in the test - the cone filters outflowed the stock filter when connected to a test rig but i know that they loose power compared to the stock airbox,

The reason for that is

1 - The engine does not actually require a lot of air and the stock filter is sufficient

2 - The cone filters draw warm underbonnet air which looses power - the stock filter/ intake does not

3 - The stock filter is often designed to boost torque at specific revs, - (ie - at low revs or to "fill in" a midrange flat spot) - a cone filter is not

Also, if you look at the test the better the flow the worse the filtration, the wire mesh one flowed the best but its filtration was poor

The reality is - on your car is if you switch filters you mightl just make more noise and no more power, if you are really lucky, you could make an extra 2hp, but it is unlikely

[Lenny]

Due to shipping regulations on aersols and chemicals I can't import a cleaning kit for a green cotton performance or a K&N filter

So for me its easier to swap out the filter for a new one every 18-20 months

Saves me the risk of over oiling though I suppose

I could probably purchase the cleaning kit from a local moto factors but I wouldn't pay there prices.

[higgsy]

Don't notice any difference between the k&n panel and the stock filter in performance or noise. I think it's effect is no different. I just bought it coz it is something I have always done and the price I paid was about twice the price of a paper filter, and having a cleaning kit which has another 2 cleans and oils left in it, I thought I might as well get one. Still have the paper one I took out anyway as it was like new and only had done 4k since it was changed - might switch back for a bit at somepoint.

I do respect what FOCA says (always extremely informative posts) but maybe as I have never had any probs using them and have felt better about using one ( no doubt all in my head) I always get one.

[PaulR93]

Lenny where did you get your filter from? You happy with it?

[PaulR93]

So are we saying that panel are better than a cones by stopping the most dirt?

[FOCA]

So are we saying that panel are better than a cones by stopping the most dirt?

Its the filter medium rather than the type

The paper filters filter out the most dust/ particles (stock or pattern panel filters)

the foam filters come second (Pipercross)

them the oiled cotton filters (K&N/ green cotton)

Finally, the wire mesh filters are the worst for filtration,

It also depends on the exact make, - some paper filters filter out almost 100% of the dust

When a K&N or olied filter is new, it allows more dirt through, as a layer of dirt builds up, it filters better (but still not as well as a paper filter)

The point is that on engines that have no improvement with a K&N all you are doing is letting more dust into the engine by fitting a K&N,compared to a paper filter, its only a small percentage of finer particles so nothing to get worked up about, but as K&Ns are also more expensive than stock paper filters, (ie- i can buy 5 pattern paper filters for the cost of 1 K&N) it makes little sense to fit a K&N

If a K&N is over-olied, the oil can get onto the MAF sensor, if it is a hot-wire type MAF, it works by putting a current through a wire in the intake airstream, and measuring the temprature, if the oil gets onto the wire, it can insulate the wire from the air, which can knock the air-fuel mixture out, K&N even withdrew their oiled cotton type filters and replaced them with foam types,(like pipercross ones) for some cars

Of course, its now well known (on forums etc) is that an open, underbonnet cone filter loses power because it draws warm underbonnet air (cooler air = denser air = more oxegen = more power) but the efforts car manufacturers go to with induction design is not so well known, the stock induction design on many modern cars is often designed to utilise the intake pulses/ to resonate ate specific frequency's (aka a "tuned length") and the airbox is a specific volume etc,so it boosts low-down torque or fills in the midrange flat spot- so removing the stock airbox and fitting a cone filter can knock this advantage off, the resulting loss (eg) in bottom end power cam give the illusion that the midrange/ top eng is stronger, combined with the extra noise cam give the illusion that the car is quicker - when it is not

Years ago (stock) intake design was very basic, and there was a lot of underbonnet space, so sticking a K&N cone filter on your car was an actual improvement, as time went on, intake design improved, manufacturers made cool intake systems, filter design improved, a modern filter is now about the size of a manhole cover when stretched out , it does not significantly restrict the airflow and supplies sufficient air to the engine it is fitted to, - because it is so big often fitting a different filter type or even completely removing the filter does not increase the overall airflow

So that leaves companies like Mountune to carefully develop intake/ induction systems that are actually better than the stock systems, and unless you really, really know what ylu are doing (and have access to a dyno/ rolling road etc) you are probably better off leaving your iir filter/ box/ induction stock and just replace your filter element frequently

When a paper filter is new, it flows well, as time goes on, the tiny holes get blocked, and the filter becomes (gradually more)restricted, it may look ok, but may restrict the airflow, it does this sooner than other types of filters, in my opinion, a frequently changed (6-months/ 6k) paper (stock or pattern) filter will outperform an aftermarket filter all -round on a stock or mildly tuned car , i pay £5 for mine so i get 3- years worth of filters compared to a £30 K&N, the paper filter filters better so i don't have to worry about dust particles damaging my engine (if i was using a K&N etc) another thing worth considering is you don't have to inform your insurance that you are running a stock filter, changing it frequently is just good practice/ looking after your car, will help economy too

I was on the dyno last year, i only had 2 runs, so i tried different boost pressure levels (i have an adjustable controller) i would have liked to have tried different inlet configurations, and filters, i may book a day and do that some time (expensive) i would take different filters and test them, - you could do this too if you are serious about tuning - i see you are in Moray - you could contact Wallace performance in Aberdeen i plan to take a Green cotton filter, a K&N, a Pipercross and a stock filter (all new) i may try the Pipercross venom and BMC CDA enclosed filters, i might bring an open K&N for a laugh or to show how much power it loses the tests will be run with the bonnet closed an open bonnet can give false results - you could do this yourself and post the results, if the "performance" filters show no improvement you would be better sticking with a stock filter, because of the cheaper cost, no insurance hassles and better filtration

i change my stock (cheap pattern filter £5) every 6-months 6k - thats on a tuned diesel running 160+ Hp up from 113Hp stock - the filter element is the same on all Mondeos the ST220 has the same element (so if the filter is enough fior a 220HP 3.0L- its good enough for 113/160HP 2.0L)- the Focuses, Fiestas are often the same, with the 1.4, 1.6 and 2.0L sharing the same filter size

So keep changing the stock filter and save up for an ST, leave the "micky mouse" mods for the corsa boys, it will slow them down even more

[Lenny]

Lenny where did you get your filter from? You happy with it?

Hi Paul,

I bought mine from priracing in the uk,

Mine is a green cotton performance induction filter, straight swap to the standard filter.

You can view my guide aswell as a 10% discount code and link to purchase your own green cotton performance filter,

By clicking here:

http://www.fordownersclub.com/forums/topic/36783-green-cotton-performance-induction-filter-fitting-guide/

A turbo vehicle will give more noticeable performance increase with a performance filter fitted, but most naturally aspirated or N/A as they call them; will mostly produce more grunt from the exhaust.

If you have a diesel engine,

Strongly recommend you blank your EGR (Exhaust Gas recirculation) valve

Then fit a performance induction filter in to the standard air box.

By blanking the egr you prevent 20% of waste gases coming back in to the induction chamber for recombustion.

The engine then demands 100% induction from your air box which is much better than exhaust gasses.

But in order to get maximum clean induction after blanking the egr I recommend fitting a performance filter.

Doing the above on a turbo diesel vehicle,

You will notice 0.3MPG increase, reduction in turbo lag, cleaner engine oil due to less carbon deposits from combustion, it is these carbon deposits that gather in the turbo oil feed pipe blocking the oil feeding to the turbo causing the turbo to eventually run dry and pop.

Evidence of this is most common on the early 1.6TDCi model focus prone to turbo failure because of egr valves and carbon in the oil.

I drive a 1.6tdci its now got 168,000km on the clock,

I've blanked the egr, remapped the ecu, removed the dpf, fitting a performance induction filter and I have it serviced in accordance with the manufacturers specifications.

And I stand proud to say "I've done over 100,000miles and I'm still on my first factory fitted turbo"

Thank you :)

[Lenny]

The filter element is the same on all Mondeos the ST220 has the same element (so if the filter is enough fior a 220HP 3.0L- its good enough for 113/160HP 2.0L)- the Focuses, Fiestas are often the same, with the 1.4, 1.6 and 2.0L sharing the same filter size

+1

The facelift 1.6tdci has the same cylinder type induction filter as the RS focus which is capable of running 4 times the power of mine

The trouble is; when ford charge for changing the filter and they actually didn't,

At least with a green one fitted you can tell them not to touch it, then they can't charge you for fitting something that is visibly still green and not one of there filters,

Personal experience with ford, first 3 services billed me for an air filter but never changed it in any any of the services,

I mean look at it:

[higgsy]

The thing about the focus cylinder type is that the paper ones are quite expensive. Think when I looked they were about 15 quid with discount at eurocarparts, I was very surprised at the cost as was used to seeing them for a fiver for other cars. I would have prob just gone paper if they had been a fiver but when you have to pay that much you start to think might was pay a bit more and get a serviceable filter. The good thing about these cylinder shaped filters is they can be rotated, so when I check it when I'm servicing the car I will rotate it so the part which is nearest the the intake location is cleaner.

[PaulR93]

I just bought another gen Ford filter today the car is a 10 plate and it has never had the filter changed. The guy who had it before really didn't appriecate true beauty lol

[Lenny]

I just bought another gen Ford filter today the car is a 10 plate and it has never had the filter changed. The guy who had it before really didn't appriecate true beauty lol

Mine was the same mate 2010 model was in with ford for 3 services and although they billed me for a filter they clearly never fitted,

One advantage of fitting an aftermarket filter,

Tell em not to change it, then they can't say they did change it and bill you.

[TJO]

On 13/01/2014 at 6:45 AM, Lenny said:

Hi Paul,

I bought mine from priracing in the uk,

Mine is a green cotton performance induction filter, straight swap to the standard filter.

You can view my guide aswell as a 10% discount code and link to purchase your own green cotton performance filter,

By clicking here:

http://www.fordownersclub.com/forums/topic/36783-green-cotton-performance-induction-filter-fitting-guide/

A turbo vehicle will give more noticeable performance increase with a performance filter fitted, but most naturally aspirated or N/A as they call them; will mostly produce more grunt from the exhaust.

If you have a diesel engine,

Strongly recommend you blank your EGR (Exhaust Gas recirculation) valve

Then fit a performance induction filter in to the standard air box.

By blanking the egr you prevent 20% of waste gases coming back in to the induction chamber for recombustion.

The engine then demands 100% induction from your air box which is much better than exhaust gasses.

But in order to get maximum clean induction after blanking the egr I recommend fitting a performance filter.

Doing the above on a turbo diesel vehicle,

You will notice 0.3MPG increase, reduction in turbo lag, cleaner engine oil due to less carbon deposits from combustion, it is these carbon deposits that gather in the turbo oil feed pipe blocking the oil feeding to the turbo causing the turbo to eventually run dry and pop.

Evidence of this is most common on the early 1.6TDCi model focus prone to turbo failure because of egr valves and carbon in the oil.

I drive a 1.6tdci its now got 168,000km on the clock,

I've blanked the egr, remapped the ecu, removed the dpf, fitting a performance induction filter and I have it serviced in accordance with the manufacturers specifications.

And I stand proud to say "I've done over 100,000miles and I'm still on my first factory fitted turbo"

Thank you :)

Hi lenny, i would like to ask which of these are the best air filter for you? Pipercross, K&N E-2993 or Green cotton filter? Im planning to change mine next week. Btw i got a Mk2.5 Zetec S 1.6L TDCi. Thank you

[Lenny]

20 minutes ago, TJO said:

Hi lenny, i would like to ask which of these are the best air filter for you? Pipercross, K&N E-2993 or Green cotton filter? Im planning to change mine next week. Btw i got a Mk2.5 Zetec S 1.6L TDCi. Thank you

Most efficint is the Green Cotton 

Best for performance is the K&N E-2993

[Jethro_Tull]

Either a wet foam filter, like Pipercross, or a dry foam filter, like Ramair.  The foam flows better than oiled cotton, and filters better than oiled common, with much less risk of contaminating inlet tract sensors.  That's why over half the Forumla 1 grid use Ramair, but none use K&N.