Hi there everyone I have a 2016 mk3.5 facelift focus st line. I was considering an induction kit upgrade on my ecoboost but having done research I have heard how effective the rs airbox is with the open top etc. They say it fits the St but looking at it, it does look as though it fits and looks like my airbox and was thinking of getting one and putting in an improved element. Can anyone confirm if this will indeed fit thank you so much

The lid should fit no problem. I don't know if the outlet will be the same diameter or not though.

AFAIK, once the bonnet is shut it doesn't make a lot of difference noise wise as it's designed to seal against the underside of the bonnet.

You get more of a sound having bonnet vents, also help get cold air in from vent and front.

The lids as Alex has said are the same, the mk2 and mk3 bottom part of the airbox are different.

You can also get bigger snorkels which are standard on the mountune and rs500 airboxs.

This is only viable to go this far if you want POWERRRRR!!!!!!!!!

i made my 1.6 tdci airbox in to the style of the new RS box, the difference in noise is fantastic :) course I haven't a scoobie if that is the same for a "good" car but hey, I like it

3 hours ago, Dee_82 said:

i made my 1.6 tdci airbox in to the style of the new RS box, the difference in noise is fantastic :) course I haven't a scoobie if that is the same for a "good" car but hey, I like it

Get some pics up Dar', I'm curious to what you have done, what filter are you using etc. Cheers.

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that was taken a wee while ago, I tided it up a bit but its mostly the same as that. not much to look at but it does the job. I know it doesn't have the honey comb look about it, bu frankly, I couldn't be bothered, it would have had to have been circles and in the end I don't think it would make any difference other than the look.

it gets a little more dirty than normal but certainly not to bad, the airbox is protected by the slam panel, you cans see the engine cover takes a beating but the airbox is relatively clean, the dirt on the inside was there before I cut it up, I hadn't got around to cleaning it.

Ahh so that's the standard air box been cut to the same shape as the RS one, and some rubber moulding glued on top, very ingenious.

What filter is it ? Looks like a green cotton one.

Don't know if I could get away with that, as I've now fitted bonnet vents, I'll have to see where the the vent on that side is in relation to the air box, don't want moisture and crap getting in there, although saying that, that's what's on the RS.

oh yeah, its a total hack job :) but sounds amazing, a year on and it still puts a smile on my back when I boot it.

yeah its a green cotton one, I did get an open ended one a while back but the sound was terrible, I think it was too close to the side so rather than making it sound throaty, it turned in to a whine, that's when I saw the RS air box and figured, that is virtually identical to mine, if its good enough for an 300hp RS, then its good enough for my 135hp zetec

not sure where the vents run on yours, the rubber is just a door seal and connects to the bonnet when its down, I don't think it would be in the way of your vents but I'm not sure it would connect with the bonnet either, I have the bonnet liner still attached so it all lines up nicely

The RS airbox lid is taller on the Mk3, does that seal actually touch the bonnet?

The box is taller and does seal with the bonnet lining.

the lid (which is all you need really will fit most ford and and some Volvo airboxes. Fits on my mk3 1.6Ecoboost and my other half's mk2.5 1.6 TIVCT and my buddies 1.6 mk3.5 1.6 diesel. (as long as each has the cylinder air filter.)

no difference in performance other than louder induction sound for all.

Worthwhile upgrade overall I have found. - even if it just makes a little more of a turbo whoosh on boost.

37 minutes ago, Tomson said:

The box is taller and does seal with the bonnet lining.

the lid (which is all you need really will fit most ford and and some Volvo airboxes. Fits on my mk3 1.6Ecoboost and my other half's mk2.5 1.6 TIVCT and my buddies 1.6 mk3.5 1.6 diesel. (as long as each has the cylinder air filter.)

no difference in performance other than louder induction sound for all.

Worthwhile upgrade overall I have found. - even if it just makes a little more of a turbo whoosh on boost.

So it should fit my mk 2.5 1.8? 

55 minutes ago, alexp999 said:

The RS airbox lid is taller on the Mk3, does that seal actually touch the bonnet?

yeah, there is a small outline on the bonnet insulation where it touches, I'm not sure it would seal up if you didn't have the insulation though.

23 minutes ago, Commencal24 said:

So it should fit my mk 2.5 1.8? 

The theory suggests so, however, check your lid with someone who has a mk3 just to be sure before you fork out 90 notes. 

That's interesting to know, problem is I don't know anyone with a Mk3 😕

Here's the airbox on my RS now fitted with a Revo filter

The rubber around the top seals to the bonnet lining. I took the lining out and the induction noise became very noticeable




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www.tomholroydphotography.co.uk

I think that changing just the upper lid will make difference only in sound rather then performance.

The important part of the ST/RS airboxes is actually the second inlet duct that brings much more air from the bottom. And also the ST/RS do not have the restrictive snorkel behind the grill.

I will fit mine at the end of the Jun/2017 to 1.5EB:

I definitely know that 1.6Ecoboost engines have problem to fit the second inlet duct because there stands a sound symposer in way. So you have to delete there first.

Hope that in 1.5EB it is different.

 

22 hours ago, Bannko said:

I think that changing just the upper lid will make difference only in sound rather then performance.

The important part of the ST/RS airboxes is actually the second inlet duct that brings much more air from the bottom. And also the ST/RS do not have the restrictive snorkel behind the grill.

I will fit mine at the end of the Jun/2017 to 1.5EB:

I definitely know that 1.6Ecoboost engines have problem to fit the second inlet duct because there stands a sound symposer in way. So you have to delete there first.

Hope that in 1.5EB it is different.

 

Correct! My 1.6eb only has the lid fitted, not the lower half as the pathway for the secondary snorkel is obstructed. But I may take the lining away for more noise... and to hopefully reduce the temps in the bay

Can you just buy the RS air box lid rather than whole airbox.  I remember when I did my air filter for the first time a while ago the circler plate on the end of the air filter wasn't clipped in correctly it made a nice noise was tempted to leave it that way lol

8 minutes ago, JONATHAN_11_80 said:

Can you just buy the RS air box lid rather than whole airbox.  I remember when I did my air filter for the first time a while ago the circler plate on the end of the air filter wasn't clipped in correctly it made a nice noise was tempted to leave it that way lol

Nope, I've just had to order the whole box with filter.

hmmm might buy a standard air box and drill it and put the seal around it lol

Just now, JONATHAN_11_80 said:

hmmm might buy a standard air box and drill it and put the seal around it lol

The RS lid is taller to reach the bonnet.

It is possible, but only form some sellers in US. Here in EU you can get it only as a whole piece + air filter.

Anyway the whole box is very cheap from US so just take the lid off it, hehe:

https://www.tascaparts.com/oe-ford/g1fz9600a?origin=pla&gclid=CjwKEAiAz4XFBRCW87vj6-28uFMSJAAHeGZbe5q--XJoL-LXjPsS3m93gdBD0X1nh-QAqlYLQRsj5BoC8__w_wcB

 

1 minute ago, Bannko said:

It is possible, but only form some sellers in US. Here in EU you can get it only as a whole piece + air filter.

Anyway the whole box is very cheap from US so just take the lid off it, hehe:

https://www.tascaparts.com/oe-ford/g1fz9600a?origin=pla&gclid=CjwKEAiAz4XFBRCW87vj6-28uFMSJAAHeGZbe5q--XJoL-LXjPsS3m93gdBD0X1nh-QAqlYLQRsj5BoC8__w_wcB

 

By the time you add shipping, duty and VAT it will probably cost the same as from a dealer anyway though?

Bought mine from an authorized Ford shop for 90Euros (just the box + filter). My dealer offered me 110Euros for the box. Have no idea why it is so expansive here in EU.

But you are right, the US price might be really close if you add shipping, duty+vat

Just picked up my new box this lunch time.

I'll fit it after work, just trying to think of somewhere I can go test it as my exhaust is a bit loud to rev outside my flat, haha.