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Green Cotton Performance Induction Filter Fitting Guide


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ive done some research on the internet prior to choosing the correct brand of replacment induction filter,

most would assume that the best choice to be K&N but i have found Green Cotton Air filter to have the edge over K&N or PiperCross due to Green's manufacturing process being more hands on instead of automated manufacturing.

the green filter in bonded with precision to the frame of the filter the results are more air flow in to the filter where K&N use an automated process resulting in over use of bonding glue to the frame of the filter which can spread across the panel restricting flow and performance of the filter leaving is performing less than K&N's original prototype that they use to get their gains figures from.

but anyways enough of me blabbing on about the differences, because the information is available on other websites for all to view without me re-typing it lol.


to purchase a Green Cotton performance induction filter for your ford and feel the difference for yourself log on to http://www.priracing....php/144/1/ford

and get 10% Discount off your Green Cotton Performance filter by using the code FORDOWNERSCLUB10

you can also get 20% Discount off any Ritchbrook branded stock by entering Discount Code: RICHBROOK20

both offers are eclusive to members of fordownersclub.com special thanks to Ross at Priracing for this kind offer.

So here's whats in the box for the focus 1.6TDCi induction filter.




Ive decided to upgrade the standard ford induction filter in my 1.6TDCi focus to a free flowing high performance induction filter. and since i was changing it ive decided to create this guide to show others what is envolved aswell as report on the performance difference between the stock and aftermarket direct replacment air box filter.

fitting time takes around 15-20 minutes,

Tools required are an 8mm socket and a pair of rubber latex gloves


So Open the bonnet,


remove the battery cover if fitted.

and using the 8MM socket loosen the 4 bolts that are holding the lid of the induction box in place.

please note the bolts do not pull free/seperate from the lid,

they remove from the bottom section but stay inside the lid section by design,


Once lid has been removed you will see your heavy stock ford filter,

hopfully ford wont have bent your stock filter when putting it in their as they have done with mine.


place your hand on the top end of the filter and pull upwards to remove it.

once removed, ensure the lid from the induction box aswell as the 8mm socket are stored off of the engine bay and close the bonnet if you are planning to wait a couple of minutes prior to fitting the new filter. this will help prevent any contamination getting in to the induction pipes.


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Here are some images of the stock induction filter removed from the induction box, it is heavier than the replacment and it manufactured with a paper style material that becomes very soft and britle when wet or damp,

wet or damp conditions can occour in the induction box in both winter and summer being caused by the heat of the engine creating condensation in the air box,

thankfully the material used in the Green filter is cotton a much better material for this type of filter and alot more breathable in both damp and dry conditions.


as you can see more clearly in the image below,

the stock filter was bent when installed and i assume by my local ford dealership last march when it was booked in for a full service, thankfully by fitting the Green filter in the induction box,

ford wont have any reason to touch the replacment filter any time soon because its good for 80,000 miles,

when that distance has been clocked

Priracing also stock & supply cleaning kits for the induction filters to renew the life for a further 80,000 miles.


as you can see in the image below,

the inside area of the stock filter is very small and the 117 pleates seem to be crammed togeather very tightly,

to be honest i wouldnt consider the stock induction filter to be sufficent enough to breath through air for myself never mind the engine and a human body wouldnt vacum as much air in as a car.

i really didnt expect it to be so restricted,


Since i had the filter removed i decided to take the oppertunity to clean out the induction filter housing,

and i spotted what i assumed to be a stone in the base of the air box, i couldnt reach in to pick it out with my hands so i had to fetch a tweasers from the tool box.


To my surprise

it wasnt a stone at all :o

as you can see in the image below, it was a Snail :D i know diesel engines are said to be slugish but i didnt ever expect to find a Snail stuck inside the air box, it would be fantasy to assume that he got sucked off the road in to the induction box, :lol: but i can only assume that he went in their when the car was in it's 6 month storage period earlier in the year. perhaps he thought he found a mate with the Garret GT1544v Turbo situated to the left of the induction filter housing.


I used to Matt finish Armor All dashboard wipes and a hoover to clean out the inside of the induction filter housing, then closed the bonnet for 15 minutes allowing the area time to dry before fitting the new free flowing Green Cotton Performance Induction filter.


I decided to meassure the differences between the filters to observe if their was any.

i found that had ford not buckled the stock filter installing it in to the induction housing the it would be the same height as the Green Cotton Performance Filter at just under 8'' Inches.


The filters differ in width/diameter though,

the stock filter is 6'' inches in width/diameter and the new Green Performance Filter is 5.5'' in width/diameter

this will allow more air circulation around the filter inside the airbox, aswell as more base clearance in the unfortunite event of any water engress due to flooding, the Green Cotton filter is positioned .5'' higher in the induction housing aswell as being constructed of Cotton it wont store much moisture compared to the stock paper style filter that could potentially store up to 3 times its size in moisture.




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Overall the Materials that have been used to create the Green Performance filter are considerably better than the stock ford induction filter,

this can be most clearly saw on the image below with the support bar to prevent folding of the filter.

ford have got a similar type of support on the stock filter but it is less than 1mm thick and of flat design which makes it usless due to its ability to kink easily thus weakening the structure and allowing the filter to fold as it has on mine.

Green Performance have addressed the issue much better by fitting round stainless steel supports which have no corners to kink and would withstand much much higher pressure than the stock filter support,

To give you an idea of this:

if you were to squeeze the stock filter support bar then it would bend, </strong></p>

but i reckon if you were to hammer the suppot on the Green Performance filter, it still woundt budge or deform.

Quality Stuff all round. B)


In the images below you can see for yourself the bonding of the filter with no glue, or plastic obstructing the flow of the filter and a consistant straight edge around the housing.


Below is an image taken of inside the Green Cotton Performance Filter,

Their is much more room for air and you can even see much more light through the 0.1 Micron holes in the cotton. resulting in free flowing clean filterd air going in to your motor as it demands.

resulting in less lag and a perfect mix of fuel and air, resulting in better engine performance, better sound and more MPG.


The Image Below is inside the stock Ford Induction Filter. :(


At this point the induction filter would be dry and free of contaminants,

so time to get fitting the new performance filter! :D

Image2390.jpgRemove the plastic cover from the filter and put on the latex gloves to prevent any dirt on your hands from staining the lovely Performance Green colour of the filter that is much like the focus RS


Align the filter rubber base up to the pipe ensuring the induction pipe is inside the filter rubber flap,

i found the easiest way to do this is to gently push the filter on to the pipe while rotating it in one direction,

by rotating it you will pass through the full seal area and be able to stretch the rubber flap of the filter around the pipe forming a good Clean seal.


Once the filter is positioned on the induction pipe correctly,

The next step is to rotate it while gently pushing at the same time, in order to bring the lip of the filter flap to the bottom of the induction pipe and tight to the wall of the induction filter housing as you can see in the image below.

Image2401.jpgwhen the filter is positioned fully home, as saw in the image above this text,

then it should slot in to the two teeth on the opposite wall of the filter housing as saw in the image below this text.

Image2400.jpgTheir is also a rubber plug that holds the unduction housing in the engine bay and helps to prevent vibration,

mine came loose when cleaning the induction filter housing so its a good precaution to ensure it is pushed down when fitting is completed.


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The filter is now fitted tightly in position,

their is no guidance on either filter in regards to where the support bar section of the filter should be positioned, but i decided to position it in the same place that the stock one was damaged,

it may prevent any damage from happening or support a weak spot i dont know but its as good a place as any,


Final step is to replace the housing and re-tighten the four 8mm bolts,

take care to ensure that the right side of the lid is sitting in to the groove on the top end of the induction filter because the top section of the filter is also the side wall of the induction box,

this design by ford may be to assist cooling inside of the housing.





Finally replace the battery lid and close the bonnet,

take the car for a drive and feel the difference for yourself,


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On Tuesday, October 02, 2012 at 9:32 AM, Richiemac said:

Nice one Lenny, does it feel any different to drive.....performance / economy etc........

Thanks mate,

The gear change is more positive especially from 1st to 2nd

0-60 is quicker getting from 10kmh-30kmh the engine and turbo don't gasp for air anymore and you can hear a nice additional grunt from the engine aswell as the wistle of the turbo.

I'm not lying when I say its the best mod I've done to the car, I feel I have helped the engine by giving it the air it required.

In regards to mpg it has made a difference because I don't have to push the accelerater as far to get a response on take off due to the Green Cotton Performance filter being less restrictive.

But I'm not sure about figures yet to be honest, I was up in trim two weeks ago at souhan exhaust's got the Piper 3" stainless DPF back Duplex exhaust fitted aswell as an ECU remap to bring it from 90-120bhp so with this done and the filter fitted I'm currently getting a reading of 4.2litre's of diesel to 100km distance traveled.

So on a 50litre tank that would be 745.6 miles but I'm sure I could get better if I keep her tidy

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Once again, great guide mate, well done ;)

Very detailed n informative.

Got me wanting to get one now

Thanks mate,

I highly recommend upgrading to one of these Green Cotton Performance Induction filters from priracing.com when funds allow, or when your existing filter is due a change, you really will feel, see and hear the difference.

And don't forget to insert the discount code: fordownersclub10 to get your 10% Discount.

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Just ordered one now, recommendation from Lenny is good enough for me.

The one to fit my car is a flat panel but i assume it's as easy to fit.

Nice one mate,

When it arrives maybe on Saturday or when you have the time, could you take some pictures of your fitting to the 1.8TDCi and either edit your post which is close to the 1.6TDCi fitting posts or create a new post on this thread with information on fitting to the 1.8TDCi to best assist others mate.

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Nice one mate,

When it arrives maybe on Saturday or when you have the time, could you take some pictures of your fitting to the 1.8TDCi and either edit your post which is close to the 1.6TDCi fitting posts or create a new post on this thread with information on fitting to the 1.8TDCi to best assist others mate.

Will do so, no problems.

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Quote taken from the Future,

Posting it here to give full options to new readers

My Green Cotton Performance Induction Filter has now reached the end of its life,

Rather than immediately purchase i replacement from Green, i studied the market to see if anything better had been developed.

So to recap in terms of evolution across the past five years,

Started off here: Image2378.jpg

Moved on to Green Cotton Performance:Image2403.jpg

Now moved on to the K&N E-9289 filter.IMG_20150801_110353_zps6xpm820j.jpg

My findings were that K&N have manufactured a kit called the 57s-4000

I've purchased mine from ProdigyMotorSport

Link: http://www.ebay.co.uk/itm/151572141725 IMG_20150801_085704_zpsssr4yqpb_edit_143IMG_20150801_084944_zpsmwpndd2u.jpgIMG_20150801_085253_zpscorm3so0_edit_143

This kit from K&N consists of a K&N E-9289 cylinder filter same diameter as stock filter but it has more pleates than standard making it larger in terms of induction space within the same area.IMG_20150801_110126_zpsnuppojdq.jpg

The filter also boasts a large side induction section which is a mushroom filter inset to the top of the cylinder drawing in cold air from behind the headlight.IMG_20150801_112122_zpsxd2t7fjw.jpg

Here is a picture taken inside the K&N E-9289 filter you can clearly see the inverted mushroom at the top of the filter.IMG_20150801_110101_zpsgi8irykn.jpg

Compared to the standard performance filter which is just a blank end:Image2392.jpg

And here the stock filter:Image2382.jpg

The side induction filter is in my opinion definitely the way forward; the design is simple and ingenious guaranteed cold air induction incorporated in to the stock enclosure.

The K&N57s kit also comes with a replacement air box lid its raised higher inside compared to the stock lid aswell as being a polished smooth surface:IMG_20150801_085328_zpsnlktpakv.jpgIMG_20150801_110457_zpsr8cexaqq_edit_143

The kit guarantees an increase in horsepower: IMG_20150801_085046_zpsk7aamfew_edit_143SciFiFantasyHorse_PowerhorsepowerjpgrZd3

K&N have even supplied two +5bhp stickers to ensure an increase in performance is felt.IMG_20150801_085436_zpsjod66d1c_edit_143

In competition now:

Green now also manufacture a filter with side induction:

The green filter with side induction doesn't come supplied with a larger induction lid or side cap its just the filter itself.

Link: http://www.fswerks.com/products/green-filter-high-performance-cone-air-filter-ford-focus-escape-2012-2013

K&N also provide the filter with side induction as a stand alone item without a larger lid or side cap if desired: http://www.ebay.co.uk/itm/K-N-E-9289-High-Performance-Replacement-Air-Filter-/131446800923?pt=LH_DefaultDomain_3&hash=item1e9ad7021b

I have to say;

I've closely examined the build quality of the K&N filter and i cant see any excessive glue on the surface of the filter or any imperfections due to "mass production" as claimed by Green in the first page of this guide.

Having the K&N57s kit now fitted; IMG_20150801_112016_zpsyyjkiwp5.jpg

The exhaust tone has a bit more grunt to it,

The induction sounds great especially at around 3,000rpm in 3rd Gear onwards.

The performance is increased aswell I've not driven it myself but the wife says it feels like the increase from blanking the EGR valve.

In terms of MPG i was already getting 70MPG so it can only get better.

Overall my advise would be;

The Green Cotton Induction Filter linked and fitted on page 01

Is a great filter provides increased MPG, performance and is still the best filter on the market for under 100 pounds.

However if your willing to spend over 100 pounds on your induction system then the K&N57s-4000

Is the best on the Market today.

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Lenny, again top work I'm going to order one. Im curious, why is the filter for my standard 1.6 (07 onwards) cost more than the TDCI models? Surely the TDCI models would get more better outcome?

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Lenny, again top work I'm going to order one. Im curious, why is the filter for my standard 1.6 (07 onwards) cost more than the TDCI models? Surely the TDCI models would get more better outcome?

Hi mate,

To be honest I don't know why their is a difference in pricing between the two filters Perhaps the 1.6 petrol was not as popular as the 1.6TDCi so the price of the Green Cotton filter for the petrol model would cost slightly more due to it being more likely to take up space in the warehouse.

Or maybe their is more design envolved in the 1.6 petrol induction filter

But the build quality is 100%

And all of the filters differ in shape, size and cost depending on model design fitment.

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Hi Lenny,

My Focus is a 1.6 Zetec Petrol model, could you five me a link to the correct filter? Would be muchly appreciated...

Hi Jordan mate,

I'm not aware of the fitment required for your model or any other model except for the 1.6TDCi

I recommend you email ross@tdcautomotive and he will be the best man to link you to the correct Green Cotton Performance induction filter to be purchased from priracing.com

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Hi Lenny,

It's cool i found the product on the website to fit my car no problemmo...

Alright mate seeing as mines a 1.6 petrol too, can you link the filter you found so I can make sure it's the one I was looking at getting too? Nice one

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Ah just thought that's not the one for my car anyway lol cause mines only the mk2 n not the 2.5 like yours. Nice one anyway that'll help other 2.5 owners out. I know what one I need anyway so it's all good ;)

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Ah just thought that's not the one for my car anyway lol cause mines only the mk2 n not the 2.5 like yours. Nice one anyway that'll help other 2.5 owners out. I know what one I need anyway so it's all good ;)

Its all good then guys,

If ever confused on filter fitment just email ross as quoted in above post.

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Sorry, to atone for my error, iv attached the correct link - http://www.priracing...tton-air-filter

I was in autopilot mode when you asked for the link...

Lol wasn't your error mate it was mine, I just generally asked the one you needed as we both have 1.6 petrol, forgetting are mk's are different so would need different filters.

Nice one for linking the mk2 one for me as well though mate, confirmed the one I thought I'd needed ;)

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Update on my fuel econemy since fitting the piper exhaust, ecu performance remap and the Green Cotton induction filter I'm now getting 947Km on a 50 litre fill of diesel. Which translates to 588.43 miles on a 50 litre fill that was a mix of motorway driving aswell as some country roads and a 20 minute sprint on a closed road at 185km/h I tried my best not to do the last one but some times it difficult lol

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