My DIY Cold Air Box

[miles]

Great idea and great finish

[Kev.O]

 

I might spray it black Kev as TBH it's a perfect fit & I doubt I could find a better suited one

 

I meant the silicone hose/pipe!

[jevansio]

I meant the silicone hose/pipe!

Lol, oh yeah ,

 

Yip I have some black hose that will do the job nicely

[Suprab1]

Looks great well done.

[captainchaos]

very nice fella, if you want to get rid of the rivets give me a shout and can get the lads to weld it up for you

[jevansio]

Cheers Chris, I may have a solution but it it fails I'll give you a shout,

[jevansio]

I've just bought some digi thermometers to get an idea of inside/outside temps of the box, they measure -50 to +70C, will that be adequate for measuring air temps (esp near the turbo)?

[Krister]

Very inspirational, nice work.

 

Now give it a quick polish to blend it more to your engine bay.

[jevansio]

Cheers Krister, yeah the brushed look stands out a bit in my bay now

[jevansio]

This is the complete item. I've used heat resistant tape around the sides.

 

 

Will get the temp data uploaded early next week

[jevansio]

Right, I've had a chance to grab some temp data from the box. I bought 2 temp probs, & put one inside the box & one just in front of where the intake pipe goes through the side (ie in the engine bay).

 

Ambient temps are around 8 deg c.

 

Box Temp	Bay Temp	Driving Style
7		32		5 mins of light no boost driving	
8		38		5 mins of light boost
9		42		Couple of strong pulls
9		39		5 more mins of light boost
9		44		5 more mins of light boost
9		52		5 more mins of light boost

The bay temps seemed to be getting hotter & hotter. As soon as I stopped to check the temps & open the bonnet the box would climb a couple of deg's and the bay would start dropping again.

 

As suspected, box temps are pretty much ambient, I didn't realise how hot it got in the bay though. Without the box the intake temps are scorching, no wonder it's pulling like mad now

 

Can you imagine how hot it is under there on a high 20deg ambient day!!!

[EdMorris]

Just read this whole thread, very interesting, especially the temp comparisons. A job worth doing then, and well executed. Nice one.

[jevansio]

Cheers Ed, yes I was very impresssed with that temp data, might do it again when the summer is here

[Tom]

Impressive

[danger_supe]

SUMMERS HERE!!

 

any more readings? :d

 

impressive thread, i have been meaning to try this for ages, found another thread with a "blueprint" of the box dimensions and layouts etc, complete with lid (i only have it in pdf version and is almost 3mb so cant attach), but your version looks alot easier and yet still very effective

 

after seeing your bay temps i imagine they're a lot hotter than an NAs bay, but still they get pretty warm, so i think i should try this soon

[Luxluc]

Just went through your complete thread Jay : very impressive.

 

Great work mate

[Swampy442]

Also just re-read this and Im deffo going to do something similar for mine. Id love to build something similar but finding a way to incorporate the standard Toyota panel filter

[jevansio]

Update

 

I've not been quite happy with the cold air box, not sure if it's the size, or the fact it's not totally sealed. I've been mulling over for a while now the idea of using a barrel around the filter which is fed by the existing feed I made so that the intake is completely sealed from the bay (like the OEM one).

 

My filter is 7" (177mm) diameter, & I found some 200mm tube on ebay, I wasn't sure if it would be big enough as it only leaves 10mm around the edge for the air to get to the filter. I ordered it anyway, but while I was wandering the house I saw something that may have been perfect, a tub of whey from way back:

 

 

 

Next up I cut the top and bottom off, by a massive fluke the lid is EXACTLY the same size as the neck on my filter

 

 

 

Next the filter pushed in, that's the filter neck sticking through, it's such a tight fit it needs no adhesive at all

 

 

And the original bottom taped back on.

 

 

So the plan was to cut a 4" hole and seal it against the 4" cold air feed I have coming into my bay (see start of thread for pics)

 

 

But it was at this point where I started having doubts if a 8" barrel was big enough as there didn't seem to be great deal of free volume for the airflow to get around the filter. So I looked again on ebay and managed to find a 220mm diameter tube, so I bought that too and figured I would turn this black one into more of a shield. It would obviously be dumped when the 220mm tube turns up.

 

So this morning I took the bottom off the barrel, and cut a hole so the airflow from my external feed would blow straight onto it

 

 

And here's the final version in situ

 

 

I much prefer the "barrel" as opposed to the "box" in the bay aesthetically, so looking forward for the big barrel to arrive now so I can do a final supersize sealed version

[Swampy442]

Im not convinced by this and the fact it wont cause a restriction. Unless the final barrel is huge of course. I thought the box was ideal and the figures were good

[jevansio]

Im not convinced by this and the fact it wont cause a restriction. Unless the final barrel is huge of course. I thought the box was ideal and the figures were good

I think a 220mm barrel should be more than enough, when you compare the area of the 4" intake (12.5 sq in) the gap around the filter to the 220 barrel is more than adequate to flow that air

 

The box did a good job, I just wanted something a little less of an eyesore, and a TOTALLY sealed setup

 

I've been out with the shield on today and power doesn't seem to have been sacrificed, RLTC is working overtime in 4th (roads are dry), it pulls like a train even with the RLTC cutting in, and it's actually pretty scary to drive as it's been a while since I've been in it, 1st time I put my foot down I actually backed off as it spooled as it felt so fierce

[evinX]

Are you some sort of diy king or something, first the rear seats sponge and now this cover, it looks stock smart!

[jevansio]

Im not convinced by this and the fact it wont cause a restriction. Unless the final barrel is huge of course. I thought the box was ideal and the figures were good

I've done a little diagram to illustrate my reasoning for the barrel size

 

 

It's a cross section of the filter & barrel. The air will be fed into the barrel side, I plan on mounting the filter off centre to give maximum airflow at the start (bit like an intercooler end tank).

 

Also the air will flow in both directions around the filter.

 

So I have 43mm of space to play with (220mm - 177mm). I plan on leaving around 33mm gap at the bottom & 10mm at the top (1.3" & 0.4" respectively).

 

The filter is 8" deep. So the area availble for airflow around the filter on each side at the start is 8 x 1.3 = 10.4 sq in. And I mam assuming I have 6.2 sq in coming in (half the 4" intake pipe).

 

This 10.4 sq in reduces linearly until the top (the point where least air needs to flow).

 

I'm obviously not a fluid dynamics expert, but I'm hoping the fact the point where the air needs to flow is 2/3's bigger than what is required is enough to cause the filter itself to remain the biggest restriction in the intake flow

[Swampy442]

You seem to have it all worked out mate Im still not convinced lol. Where did you get the idea from?

[jevansio]

You seem to have it all worked out mate Im still not convinced lol. Where did you get the idea from?

I like when people question my ideas, as sometimes I look over obvious stuff.

 

I dunno, it's like the most convenient shape to encompass my filter, it just made sense

[Swampy442]

Cool, I just want to see the results Actually I just had a thought

 

http://www.bmcairfilters.com/carbon-dynamic-airbox_prd_pr3_4_1.aspx