Custom air box

[Niall]

Right guys I'm really suffering from IAT issues and a big part of it is due to the location of my air filter. Behind the rad where its having hot air pumped straight through only to be heated up again by the supercharger. So to combat this, I'm looking at building a custom air box to house the air filter to deflect the heat away from the rad and force cold air from the front of the car in. This is the first time I've done something like this so have a few questions.
Firstly, Material? My two options are have it tigged up in ally. Will be expensive and may look a bit unsightly. Second is i mould it from fibreglass which is seeming more appealing right now. As far as I'm aware, fibreglass should resist the bay heat a bit better than metal and i can form that to any shape i want around everything in the way. Should also be cheaper. Any other benefits to any other materials?

Secondly, air flow. I was planning on using the original scoop off of the slam panel directly into the air box but will that flow enough air? I could always take a scoop from behind the lower grill for a second feed into the bottom of the air box but I'm always wary of this due to picking up water and Matt bushing my engine :p

Will also have the recirc valve feeding back into it as well but thats not an issue as that can feed straight into the bottom where the recirc is mounted anyway.

Cheers all

[silverzx]

Whats wrong with some steel / SS sheeting?

[Grant]

Why not just use an enclosed filter with a dedicated air feed?! Have a heat shield round it out of stainless steel. Cuts out a f*ck ton of fabrication work/cost.

[Piggy]

If you can...use some gold foil....brilliant for keeping heat off.

One of those little bonnet scoop things which sits flush maybe an idea...can look quite sleeper and inconspicuous if done right and colour matched

[bashbarnard]

The vw boys often put them in the wing then have slots cut. Eliminates most the issues as filters not in the bay. Just use a good quality hose between the two then.


Like this one a friend had

[Niall]

Sod having some gay holes cut in my wing lol
I would use a aftermarket enclosed filter but room really is an issue and getting the pipework around from the charger to the area where the filter is.

[bashbarnard]

Its not everyones cup of tea granted but it works. An enclosed filter would be the way forward though

[Grant]

So you don't have room to have an enclosed filter, but you have room to make a custom air box?



Why not focus your efforts on making a custom air feed? That is the bare roots of the problem. You need cold air getting to the filter.

[RetroPug]

https://www.youtube.com/watch?v=xSCtRNhb6JE

This is a great video.


If it is a simple-ish shape you can cut and bend a big sheet of alloy into box shapes, not necessarily a cube but not really with curves, and then rivet the folds together or just have that one bit welded. I have made 2/3 enclosed filter shields this way, a box would be just as easy, just like at school when you printed 2D schematics on paper and folded them up into cubes etc.

[Eeyore]

I need to invest in a 3D printer!

[Toms306]

Does the filter temp make that much difference? Surely the charger heats it up a lot more anyway? So a bigger IC might be more beneficial than a better cold air feed?

[Niall]

So you don't have room to have an enclosed filter, but you have room to make a custom air box?



Why not focus your efforts on making a custom air feed? That is the bare roots of the problem. You need cold air getting to the filter.

Yes. A standard filter box is generally square and bulky but if i can build a custom one, i can fit it to the area i have.

Does the filter temp make that much difference? Surely the charger heats it up a lot more anyway? So a bigger IC might be more beneficial than a better cold air feed?

If the intake temp is high, its a vicious cycle. It heats up the air going into the IC, hotter air passing though the IC, hotter air in the engine bay feeding back into the air filter.

[allanallen]

I'm lucky with mine being in a 205, I've dropped the rad below the grill and sat the filter right behind the grill. The added bonus is cold air is constantly being blown into the bay too, it's not perfect as it's not ducted out anywhere but it certainly helps.
Anyways I digress..... Would it be feasible to fit say a 205 rad nice and low, then open up the slot/gap/orifice in the grill?

[Jonny81191]

Why not focus your efforts on making a custom air feed? That is the bare roots of the problem. You need cold air getting to the filter.

^this. Stop mincing about wanting moar shinies and get a good feed to the filter. If you're still having issues after that, then go enclosed/custom box.

[Niall]

Would be quite a pain in the arse tbh Allen not to mention I've just fitted a brand new Nissens rad lol.
I have seen a few people do the same as you though which does seem to work well. Mine sits above the rad just (but as we all know, the hottest part of the bay is going to be the top) but due to the angle of the charger and lack of room to get a pipe out of the charger and round into the space next to it, I'm really restricted as to what i can do unless i can move the inlet pipe to the manifold which is going to be really fiddly.

[Niall]

Why not focus your efforts on making a custom air feed? That is the bare roots of the problem. You need cold air getting to the filter.

^this. Stop mincing about wanting moar shinies and get a good feed to the filter. If you're still having issues after that, then go enclosed/custom box.

Well no shit sherlock Im not just going to bang a filter in a box and thats that. Feeding a cold air feed to the filter is easy. Its just enclosing it otherwise it will still be sucking in hot air from the bay

[Grant]

Who said anything about a standard filter box?!

Why not use an enclosed filter as said, using the original gti air scoop from behind the grille to feed it with a bit of flexible pipe.

[Jonny81191]

Feeding a cold air feed to the filter is easy. Its just enclosing it otherwise it will still be sucking in hot air from the bay

Have you got a cold feed yet?

[Grant]

I really don't see how something not too dissimilar from this will not solve your problems... Still smaller than a custom box, and the same effects....

[Niall]

Who said anything about a standard filter box?!

Why not use an enclosed filter as said, using the original gti air scoop from behind the grille to feed it with a bit of flexible pipe.

Sigh.....
The reason being is a enclosed filter is quite bulky and you of all people know how restricted i am with room next to the charger. Hence the custom box which will do the same job as an enclosed filter but will actually fit in the space i have.

[Jonny81191]

Have you got a cold feed though?

[Niall]

Yes i have. Not that its very effective at the moment

[Grant]

Niall, you are talking about making a fiberglass/ally box to enclose an air filter, yet there are ones already available on the market.
How damn small of an air filter are you planning on using if you are going to get it any damn smaller?!

[Niall]

No he hasn't.

Niall, you are talking about making a fiberglass/ally box to enclose an air filter, yet there are ones already available on the market.
How samm of an air filter are you planning on using if you are going to get it any damn smaller?!

Yes i do.
You are clearly not paying any attention. its not size thats an issue (first time I've said that) but shape. Due to the angle the pipe comes from the charger and the location of the inlet pipe to the mani, the chances of finding a generic air box which will fit my filter yet fit in the space i have with a cold air feed to it are very slim. If i can find one (unlikely) or make one which will fit around the current air filter position then that will work.

[Grant]

No he hasn't.

Niall, you are talking about making a fiberglass/ally box to enclose an air filter, yet there are ones already available on the market.
How samm of an air filter are you planning on using if you are going to get it any damn smaller?!

Yes i do.
You are clearly not paying any attention. its not size thats an issue (first time I've said that) but shape. Due to the angle the pipe comes from the charger and the location of the inlet pipe to the mani, the chances of finding a generic air box which will fit my filter yet fit in the space i have with a cold air feed to it are very slim. If i can find one (unlikely) or make one which will fit around the current air filter position then that will work.

But you're creating work for no reason...

Buy a generic enclosed air box, sack off the silly scoop that is evidently good for nothing under the existing filter, and put an enclosed filter in its place... If it is on flexi pipe, then the angles of the pipe from the charger pose no issue.

You know full well how hot that heat shield was getting that you made, it is serving more bad than good. Get rid of it, create more space, and fit an enclosed filter for a fraction of the price of fabricating a custom one would be.


Get some pics up, it would help this greatly..

[Niall]

Right seeing as you can't get this into your head. The smallest air box i have found that will fit my filter (already very small for the application) is 180mm long. The space between the charger and inlet pipe is 185mm so that would leave me 5mm to swing the pipe from the filter to the charger...not going to happen.
If i mount the 180mm long air box at an angle the same as it currently is then it will fit but partly sits on top of the rad which means i can't close the bonnet....no good.
I can't mount it facing down towards the floor behind the rad because there is a recirc setup there and a oil cooler.

Hence the need for a custom designed air box. I would happily fit a generic one if i can as its a hell of a lot cheaper and easier. The filter needs to stay mounted at the angle it is now which only just fits in under the bonnet. If i can enclose it making use of the space i have (not a generic air box because it won't fit) then it will not suffer from heat soak from the bay and i can feed it from a flexi pipe underneath which i can wiggle round to the grill somehow.

[Seb_Ryan]

Cant you not put it down roughly where standard box sits?

Apart from that make a custom heat sheild from the malteaser boxes etc (the round ones) haha

[Niall]

Nah that area is full of oil coolers and boost piping lol
Why did i not think of that! lol

[Grant]

I really don't see how you can't get a filter parallel to the radiator using flex pipe? Cut the silicone so it is not pointing back towards the engine, and have it running parallel to the inlet.

As below, sack off the metal scoop that is doing no good what-so-ever, and have the 'can' in its place.









You're creating so much work for nothing IMO. There will be somewhere to mount it, if not there...

[Niall]

Because if the filter is parallel to the rad like you're suggesting, the bonnet squashes it so won't fit with a big enclosure around it.

Anyway, does anyone with half an ounce of sense have an suggestions?