Hi everyone. Have any of you mk3 & 3.5 owners spotted the new RS air filter box? I might take a hole cutter to mine to complement my K&N once ive seen the underside of the RS bonnet that the rubber seal compresses against for a comparison to mine. It should give some extra induction roar!

I suppose i could just take my lid off though to save drilling it!

Excuse the poor picture, I took it from this months Fast Ford magazine with my phone camera.

I wonder i this will benefit my car

Ive got the filter out of the K&N 57s-4000 kit with a removable end bung in mine at the minute. I see the RS is running a standard filter though with an open box to give the induction roar.

I think i will just remove the lid on mine tbh lol

I think i will just remove the lid on mine tbh lol

If you take the lid off your car will begin to suffer from heatsoak I'm afraid! Nice idea but it wouldn't do the car any good

If you take the lid off your car will begin to suffer from heatsoak I'm afraid! Nice idea but it wouldn't do the car any good

No different to an open induction filter and at least it will still be getting a cold air feed from underneath. I know where your coming from but I would like to see both options rolling roaded.

The way I see it, is if I came with a cover they did it for a reason. They wouldn't spend money on Things that need it. after all.. on a large production scale, one extra part can end up costing alot

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intresting wonder how much the cover would be from ford?

Looks like the only difference to the ST is the lid.

But bear in mind, that top air feed could be planned with the design of the front bumper to channel cool air to it.

We also can't see if anything has been fitted to the underside of the bonnet to help shield and channel cool air, rather than hot under bonnet air.

looking at the pic i would say it has the bottom fed like the ST as two pipes come off the one intake, the new box looks like it seals to the bonnet very tight possible.

If any air is channeled up there would be very little as the headlight and other plasics in that are would mean very little reachs it. Same if anything is fitted to the bonnet to channel air i will be very tight with such a small space to fit in and where would it pull the air in from?

its almost like the KN 4000 kit with regards to air draw, just with the hole in a slightly different place really and larger.

It is probably more for noise than anything else...

It would be tempting to fit to my ST if I could just get the lid.

Anyone who wants to fit to the non ST Focus would want the whole box though, the ST airbox seems like a good upgrade at letting the car breathe better than just changing the filter. Especially as the 350PS RS can breathe through the stock paper filter.

I will keep an eye out in my magazines as i would like to see the underside of the bonnet too to see if there are any additional air channels. As stated the square cut out on the front is just like my K&N removable bung albeit in a different place.

I have a brand new (but unboxed) genuine Ford Focus RS airbox if you want to buy it?

From the mk3.5?

Found a vid, doesn't show that clearly but I can't see anything obvious on the underside of the bonnet:

I imagine it is only for noise, but might be a nice warranty friendly upgrade. Quite tempted to get this and the mountune induction pipe at some point... Would rather stick to OE filter and just change annually though.