modified/upgrade/performance air filter box

[el_jefe]

Good morning one and all,

I am wondering what people have done to get their D2s breathing better, I have been looking for some form of replacement air filter box but there doesnt seem to be much around for the d2s.

I have see a couple of air boxs but none are for the D2
I admit this one is for a patrol anyone got anything similar
172225

[Kaaaiju]

Good morning one and all,

I am wondering what people have done to get their D2s breathing better, I have been looking for some form of replacement air filter box but there doesnt seem to be much around for the d2s.

I have see a couple of air boxs but none are for the D2
I admit this one is for a patrol anyone got anything similar
172225


I am making a custom air box for D2 and running one now in my D2 with a 4inch snorkel

[shack]

I think Allisport make one, but from memory is basically an aluminium version of the stock one... Which would still be a vast improvement.

One of the issues often quoted with the stock setup is that it is too restrictive when running performance tunes, but in reality there are a lot of discovery 3 tdv6 engines toning around 150-170 kw with very few breathing issues, but very similar airbox size. I'd say that some of the supposed restriction is actually the rest of the intake system, and the cheapest/ easiest mod that can be done to ease these issues (albeit marginally) is the airbox upgrade.

However an aluminium one would be stronger and hopefully less prone to flexing and letting air in, another issue is the filter blocking and getting ruptured or sort of inverted, I guess some kind of support in the lid would help alleviate this.

Cheers
James

[Four Loko]

Yeah I reckon its super restrictive and have been looking over pics of air box's to try spot one that looks close that I can modify.

I also picked up some silicon hose bits from autobarn today and will fit them up on the weekend and run a pod filter directly off the turbo seen as my tune does not use the MAF, will see if I can notice any thing.:P

[Slunnie]

I think the big problem with them is:

The filters leak around the seal
The flow is restrictive from the airbox through the inner guard.

I really like Kaaaiju's solution to that area which will flow significantly better.

[Kaaaiju]

This is what I run now, custom airbox 4inch snorkle to 3inch striaght into the airboxhttps://uploads.tapatalk-cdn.com/20210713/27cfe99a64100679faf7bedc1c820c60.jpghttps://uploads.tapatalk-cdn.com/20210713/599fde0eeda82bab95f96b132b4582d4.jpghttps://uploads.tapatalk-cdn.com/20210713/b4ffe6176ec7426c487e7ca6a8f99b0c.jpg

[Four Loko]

Confirmed, factory airbox with good sealing safari snorkel is way too restrictive goes even better now like this ha.

https://i.ibb.co/sW0nv8J/photo-2021-07-14-11-20-22.jpg (https://ibb.co/jJcmvnZ)

[rick130]

Confirmed, factory airbox with good sealing safari snorkel is way too restrictive goes even better now like this ha.

https://i.ibb.co/sW0nv8J/photo-2021-07-14-11-20-22.jpg (https://ibb.co/jJcmvnZ)Just don't take it on a dusty road. [emoji12]

[Bohica]

Confirmed, factory airbox with good sealing safari snorkel is way too restrictive goes even better now like this ha.

https://i.ibb.co/sW0nv8J/photo-2021-07-14-11-20-22.jpg (https://ibb.co/jJcmvnZ)

No wading for you.

I can't help but think that this pursuit of power is a bit silly, (Says the guy with a mild tune, about 125kW. What is should have been from the get go) My Disco goes most places. When I get stuck, it is not due to a lack of power, a lack of skill, maybe, a lack of mods, maybe. Although with a winch I can get up anything.

[Four Loko]

Good morning one and all,

I am wondering what people have done to get their D2s breathing better, I have been looking for some form of replacement air filter box but there doesnt seem to be much around for the d2s.

I have see a couple of air boxs but none are for the D2
I admit this one is for a patrol anyone got anything similar
172225


Spoke with a shop today that does a lot of custom airbox's and they were looking at a GU box as a base after looking in the engine bay with what to work with, so I think your onto the right path.

[Homestar]

Confirmed, factory airbox with good sealing safari snorkel is way too restrictive goes even better now like this ha.

https://i.ibb.co/sW0nv8J/photo-2021-07-14-11-20-22.jpg (https://ibb.co/jJcmvnZ)

Good for keeping large insects and small rodents out of your engine but not much else. Some flyscreen would be almost as effective.

[RRT]

Looking to Snorkel the D2 and whilst I have a perfectly good safari out the back have come back to looking at the Nissan Option with custom piping due to the breathing issue.

The sizing of the Nissan box
• Diameter : 24cm
• Inlet / Outlet : 90mm - 3.5"
• Base Top: 23cm
• Box Height: 15cm
• Box Height With Pipe: 24cm


Whilst the overall dimension of the D2 Box, taking into account the ridges and brackets

• Width: 28cm (across the engine bay) + 6cm for inlet
• Length: 30cm(down engine bay) - not including the outlet
• Height: 27cm - from base to top
• Height: 21cm - from cut out to top


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The concern is the forward aspect of the bottom of the airbox with the cut out due to the shaping of the under bonnet, but thinking maybe just cutting a piece of checkerboard alum to flatten the area and place / fix the airbox to that.

Happy to cut the plastic around the sensor and glue / rivet that to the new one. The inlet pipe shown below would actually become the outlet pipe.

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This sort of shows pretty much what I am looking to undertake as to the snorkel it self except cutting and running it 'inside' the panel as much as possible with 4". This would require moving the bonnet sensor and drilling out the inner guard as well.
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[RRT]

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Approximate shape of the Nissan in the area with outlet towards the current exit

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[Tombie]

Interesting...

Keep in mind - look at the inlet diameter of your Turbo... you will reach the point of no returns = given a stock airbox with a few mods is good for 200bhp and more torque than the driveline can handle, there is a point where placebo kicks in :)

Better filtration certainly wont be a bad thing!

[Kaaaiju]

Finished mine off today works well183900

[RRT]

Finished mine off today works well183900


Fantastic to see it does fit!! Just looked the demon up and it has a different base, do these use the standard patrol filter or are they a different size?
183901
Did this fit into the standard holes or was this modified?

It looks like on you pic that there is a safari snorkel rather than the metal piping that you had along with the outlet looking like a round orifice not the oval.

That being the case have you found with the different air box that the safari actually breathes well enough with the larger inlet and outlets on the airbox? would love to have a look at this install

[Kaaaiju]

The base fits just needs some new holes and panel beating

The black part of the safari is still oval as standard and just made it fit to a round tube

[Tins]

The hose at the turbo end, did you wrap the silicone yourself? Doesn't look "off the shelf". Great install BTW.

[RRT]

The base fits just needs some new holes and panel beating

The black part of the safari is still oval as standard and just made it fit to a round tube


Just did some more measurements and the outlet of the Airbox is 3" from the internal smallest diameter and this comes to a circumference of approx 27cm. The oval intake and the intake to the front panels have a circumference (outer) of 28cm so basically an oval 3" circle if you get I mean!

The Safari snorkel at the inlet (basically the only place that is round) is 3" although the 'volume' of the main chamber appears to be bigger than this, hmmm.

The Patrol intake is 3.5" so have you used a reducer to connect the pipe to the 'safari'? The picture looks like two different silicon tubes. Would a 90 degree 3.5" reducing to 3" work?

As per you pic, it would appear that it does not require relocation of the bonnet alarm or the power steering ace reservoir as you had done previously as the silicon connector between the air box and out to the snorkel would be able to be compressed somewhat to fit, would you agree?


Know for mine which a different position of the turbo intake
Loved how you mentioned panel beating, are you talking about thumping the ridge down as it appears that height is not necessarily an issue with the top of the airbox below the level of the radiator.




Would Think I will be a using a reducer off the air cleaner and recut the pipe the pipe to the standard inlet for simplicity of keeping the vac outlet and the catch can inlet/


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[Kaaaiju]

The hose at the turbo end, did you wrap the silicone yourself? Doesn't look "off the shelf". Great install BTW.


All that stuff is off the shelve silicon

[Kaaaiju]

Just did some more measurements and the outlet of the Airbox is 3" from the internal smallest diameter and this comes to a circumference of approx 27cm. The oval intake and the intake to the front panels have a circumference (outer) of 28cm so basically an oval 3" circle if you get I mean!

The Safari snorkel at the inlet (basically the only place that is round) is 3" although the 'volume' of the main chamber appears to be bigger than this, hmmm.

The Patrol intake is 3.5" so have you used a reducer to connect the pipe to the 'safari'? The picture looks like two different silicon tubes. Would a 90 degree 3.5" reducing to 3" work?

As per you pic, it would appear that it does not require relocation of the bonnet alarm or the power steering ace reservoir as you had done previously as the silicon connector between the air box and out to the snorkel would be able to be compressed somewhat to fit, would you agree?


Know for mine which a different position of the turbo intake
Loved how you mentioned panel beating, are you talking about thumping the ridge down as it appears that height is not necessarily an issue with the top of the airbox below the level of the radiator.




Would Think I will be a using a reducer off the air cleaner and recut the pipe the pipe to the standard inlet for simplicity of keeping the vac outlet and the catch can inlet/


183909

183911

183910


The silicon is all 3.5inch and fits well and just have to shape the body to fit the leg of the box on

best to get the box and modify to suit your needs as it’s much more complicated for your setup

[4runnernomore]

Looks like someone has finally done an aftermarket air box.

shame there is not a lot of detail thought. More on the 3 inch snorkel to go with it.

DISCOVERY 2 STAINLESS STEEL 3" RAISED AIR INTAKE WITH AIRBOX | Dirt Monkey Offroad (https://www.dirtmonkeyoffroadltd.co.uk/product-page/discovery-2-stainless-steel-3-raised-air-intake-with-airbox)

maybe some of the UK Bretheran could investigate and get back to the forum.

[RRT]

Looks like someone has finally done an aftermarket air box.

shame there is not a lot of detail thought. More on the 3 inch snorkel to go with it.

DISCOVERY 2 STAINLESS STEEL 3" RAISED AIR INTAKE WITH AIRBOX | Dirt Monkey Offroad (https://www.dirtmonkeyoffroadltd.co.uk/product-page/discovery-2-stainless-steel-3-raised-air-intake-with-airbox)

maybe some of the UK Bretheran could investigate and get back to the forum.



Well just finished off the Alternator and I was explaining to my BIL what I am intending to do with the just ordered GU AIRBOX which should arrive this week.

Got home and as per the request from the Mandrel bending firm, as to what I need in terms of the bends of the 4" pipe. Not having the drawing tools, so I got out the cheap snorkel and took pics with the measurements

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The airbox as we see will sit a little higher on a levelled out piece of sheet metal to 'flatten' the rise towards the rear - this may enable me to have an almost straight through turbo to intercooler piping rather than the down and up that all discovery's have, as the Darkside Manifold and turbo has the outlet in a different position to standard.

Not sure with the Dirtmonkey one whether 3" is actually large enough for a snorkel or at least my requirements.

[Tombie]

Looks like someone has finally done an aftermarket air box.

shame there is not a lot of detail thought. More on the 3 inch snorkel to go with it.

DISCOVERY 2 STAINLESS STEEL 3" RAISED AIR INTAKE WITH AIRBOX | Dirt Monkey Offroad (https://www.dirtmonkeyoffroadltd.co.uk/product-page/discovery-2-stainless-steel-3-raised-air-intake-with-airbox)

maybe some of the UK Bretheran could investigate and get back to the forum.

Bloody conical filter design though!

Essentially useless as a filter, will just dust the motor.

The GU one RRT is looking to use will at least filter correctly.

[d2dave]

Bloody conical filter design though!

Essentially useless as a filter, will just dust the motor.

The GU one RRT is looking to use will at least filter correctly.

Tombie. What do you mean by conical filter?

Without seeing inside the air filter box how do you know that it would dust the motor?

[Slunnie]

Tombie. What do you mean by conical filter?

Without seeing inside the air filter box how do you know that it would dust the motor?

The webpage says:


Genuine RAM-AIR 3" cone filter

I'm not convinced by them either.

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[RRT]

Must say have never really understood why they use the RAM style filters, especially on 4WD's, the reducing diameter is also reducing the corresponding area of filtering of the incoming air.

Suppose it could also be argued that the flat rectangle of the D2 filters offers more surface area but of course the sealing of the box is more problematic so any benefit is compromised.

[Tombie]

Must say have never really understood why they use the RAM style filters, especially on 4WD's, the reducing diameter is also reducing the corresponding area of filtering of the incoming air.

Suppose it could also be argued that the flat rectangle of the D2 filters offers more surface area but of course the sealing of the box is more problematic so any benefit is compromised.

This was one a fabricated for my Supercharged D1

Uses a late model GT element after testing flow rates.

Good for 300kw at the tyres

https://uploads.tapatalk-cdn.com/20230306/2741c39fac6fbea70107cbe3974e5add.jpg
https://uploads.tapatalk-cdn.com/20230306/3d17bdae01cb957effdc593fdebccb96.jpg
https://uploads.tapatalk-cdn.com/20230306/cd11179a50122649f3f0d3e7dba11426.jpg

[RRT]

This was one a fabricated for my Supercharged D1

Uses a late model GT element after testing flow rates.

Good for 300kw at the tyres





HOON!!!! That is gorgeous Tombie, really really impressive, maybe should have kept my D1 V8, of course, the fuel consumption may be a bit higher again, but Whoa..





So got the GU Air Cleaner today and am exited somewhat.

The air filter is 22cm around and 11.5 cm depth, so the square is effectively a 22 * 11.5 * 2 (thickness)cm versus the Mahn filter at 21 * 8 * 5cm . The Mahle Filter has a hell of a lot more pleats I would add but this one is a reusable washable cotton filter, will investigate the throwaway ones as to their construction.

So in comparison, it was evident how short the GU box is in comparison between the two side by side, but the actual size (when comparing a circle to a rectangle of course) are pretty equal and as noted the air cleaning areas are comparable as well.


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The section to mount the box will be a shape such as this one below to allow for the shape of the front section of the engine bay with tech screws to mount the plate to the floor. The height will be as high as possible to hopefully allow me to direct line the intercooler to turbo hosing .

There are a multitude of holes on the base of the air cleaner to mount the box to the plate.

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[RRT]

Just looked up the throwaway filters and there are certainly more pleats than the reusable type as expected, and, they are available off the shelf at the three auto supplies that I looked up.

reusable

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Throwaway


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[RRT]

Set out today to do some chores on the D2 as well as install the airbox, purchased a 3.5 to 3.5" 90 degree bend from supercheap to go from the airbox to the fixture on the engine bay side to inner panel, the smaller one they had was actually a good size.

So out with all the bits and pieces and started to go about where it would fit, then realized that I left the lid at home so could not place it accurately for height which I want as much as possible to straighten out the intercooler to turbo piping as much as possible.

Did consider to fit and drive home without the lid but that even for me would have been reasonably stupid!

There is plenty of room around the airbox and the underfitting would not be a difficult job especially if you have a sheet metal bender as my BIL does. The fitting does not need to be as extensive I thought but the rise in the engine is higher than I thought. It almost sat in perfectly and the multitude of attachments that came with it could have been utilised to mount it.

The box can easily be positioned to take the 90 degree bend up to the fitting on the side panel and with the silicon 3.5" wrapping nicely around the plastic, this was pretty much a no brainer.

So as I am away tomorrow up the VHC decided that we would do this in the next couple of weeks and more so the 4" snorkel is not going to nearly as difficult as the BIL thought, and the thought was we were going to come it at 45 degrees to the engine bay and maybe not 90. That said, if you had a safari snorkel and you are happy as Kaaaiju showed the fitting of this to it is maybe the simplest upgrade you would ever undertake for anyone looking at an airbox upgrade, this unless something amazingly unforeseen happens, I would recommend as the way to go.