Airbox material

**kugzs** · 21-02-2007, 12:45 AM

currently my engine bay looks something like this
http://www.toyota-nationals.org.au/g...album=2&pos=18
with the pod filter exposed on the right.

I am planning to make up an airbox and was wondering what the best materials to use are. I was thinking aluminium lined with foam rubber

are there any better options
plastic with foam rubber?

thanks

**30psi 4agte** · 21-02-2007, 01:39 AM

Ali is always a good option! Its light ,cheap, easy to work with and can be made to look very professional.

Carbon is a excellent option too. harder to work with but very pleasing in the end result.

If you have done any fibreglass work before id go with carbon. I had never done any fibre work or carbon work for that matter before and achived excellent results ( made the radiator schroud you see in my avatar.) so its not that hard to work with.

It has excellent heat transfer properties, is a low conductor of heat and looks tops !

What i would do in your sitch is what i usually do nd thats get some decent cardboard and make one out of that !!
This way you get an idea of what it will look like, if it will work/ sit how you want it and above all else give you a ready/ easily made template to start the final product.

**Ben Wilson** · 21-02-2007, 07:59 AM

For a complex shape like that, you might want to consider fiberglass.

Carve the shape you want out of styrofoam, then lay up fiberglass on the outside (use epoxy resin). Once it's set, cut your holes out then pour in acetone or petrol to melt out the styrofoam, then sand and paint. You'll wind up with a neat, light box whatever shape you want.

**kugzs** · 21-02-2007, 08:33 AM

what is fibreglass like at conducting heat/stopping heat radiation compare to CF and aluminium

**Ben Wilson** · 21-02-2007, 08:39 AM

Better than aluminium, similar to carbon.

If you were to stick a layer of foam (I can't remember the name of the stuff) between the layers in the fiberglass, you'd get a nice air gap which would insulate fairly well.

**kugzs** · 21-02-2007, 08:41 AM

thanks all

**Andrew162** · 22-02-2007, 12:23 AM

CF ftw. I had a mate of mine construct a complete air intake pipe and heatshield totally out of CF, and intake temps dropped by 2/3rd's.

The layer of foam you'd want is actually a soft version of concrete expansion joint, mostly used around the coping for inground pools, between the tiles/concrete and coping. Bunnings would have the stuff, or something similar.

**oldcorollas** · 22-02-2007, 02:38 AM

there should be little difference between CF and FG.. the fibres are not the major heat conductor, the resin is.

are you worried about noise? (think about wide flat areas or avoid them.)

if you can work with fibreglass, it will be easiest to make into complex shape (if you make the plug). double layer with foam or whatever middle layer will also be strong, as well as reducing noise and heat...

really, for just a CAI or keeping out engine bay heat, any will work fine.. just make sure you seal it up (either completely around filter, or seal to bonnet or or...)

**30psi 4agte** · 22-02-2007, 02:46 AM

Just to add a bit to OC's post.

He is right in saying that the resin is what will conduct the heat. There are different types of resin available for different purposes.- --- sort of like heat proof paint has their range of paints for different applications.

For example i used a resin which is good for over 1000 deg F for my heat shield that i made from CF
Kugz: You prob wont need to use such resin as it is more expensive but this is just more of a guide for others that might be thinking about CF for different applications.That they should be informed that they may need to use a certain resin depending on what they are constructing.

**kugzs** · 22-02-2007, 12:22 PM

some good info in this thread.

for me personally, i went with fibreglass because it was cheap and easy to get. It will be lined with a rubber foam that is specifically designed for engines (from clark rubber).
The whole airbox will cost me less than $50

i will get some pics up when i finish it.

OC can you please elaborate on your wide flat areas creating noise comment

**Ben Wilson** · 22-02-2007, 12:51 PM

A flat, unsupported area will resonate like a drumskin. If you add some curves or ribs, it won't.

**kugzs** · 22-02-2007, 01:27 PM

You must spread some Reputation around before giving it to Ben Wilson again.

**Howieau** · 30-03-2008, 09:32 PM

Would mild steel work very well at all, or will it absorb too much heat?

Also with the setup I have is isnt really possible to form a perfect seal. Will this matter too much, I figured the cold air intake pipe running from behind the lower grill on my car to the airbox would feed enough cold air in to keep it all cool. Yay/nay?