Painting Intercooler?
 

Anyone had ever spray painted their intercooler Black? Is it possible to coat the intercooler with some sort of high temperature spray paints?

I don't have data to back this up so it may be far fetched. I think that painting the IC would decrease efficiency because the aluminum would not be able to conduct heat transfer as well. Not that the paint would hold heat in(which it might) but the air would not "cool" as much as it passes through the IC fins.
Get a bar and plate IC they look awesome, if you don't like the way it looks you could put some sort of grill in front of it like a honeycomb or something similar that you could paint to color. I'm all about open flow though and would rather not have anything in the way of my IC.

Whenever you change the thickness of the material, heat transfer goes down. Also, paint does not have a very ideal heat transfer coefficient. I would never do it. Just keep it bare aluminum, and enjoy the wonders of modern engineering.

Well .. I know alot of people actually powdercoat theirs black.. more for a sleeper look. As a matter of fact alot of intercoolers came from the factory black. I believe the RX7 one did? As with the post above.. no proof numbers here sorry :(

buick national,supra mk3 mk4,dont those saab or volvos come black.

I have a black rx-7 and I have had no problems with it. It really adds to the sleeper effect!

but aluminum has an oxide layer anyway. oxide = bad heat transfer.

just get some radiator paint from eastwood and do it.

yup radiatior paint. still i love the the look of an intercooler, i'm not trying to hide it

I love getting stomped. I personally like the IC alum glow from the front. I'd spend my money on alumashine and make her even more radiant if I was gonna do anything.
I've never seen radiator paint, if it's good enough for a radiator then i see no reason why it wouldn't be ok. Then again i've also never seen an IC any other color. Make sure you take pics, I might change my mind.

Increasing area increases heat transfer, thats why insulation on pipes sometimes makes things worse (greater surface area). The heat transfer coeffcient would be greatest with aluminum (i would think)

I wouldnt recommend doing it, unless you can find the heat transfer coeffcient. If you want get a sample piece of alumnium paint it and we can do some tests and figure out if it would be detrimental to the performance.

You sure oxide has a worse coeffcient than regular aluminum?

Seriously, does it matter if efficency suffers a little? Will the end result actually make a difference how much power the car can make?

If someone really wants to know, dyno the car before the paint and then immediately after the paint dries. I'm willing to bet that there will be no difference beyond the typically % of error on the dyno.

Paint it pink!

What I would be concerned about would be the flow through the intercooler mainly. Convective heat transfer is what that heat exchanger does.

thermal conductivities in W/m-K:

Aluminum: 250
Aluminum Oxide: 30
Stainless Steel: 16

BUT! thin is in. since it's thin it doesn't take much to overcome its low thermal conductivity. same with paint. or plastic. or whatever...

fun science experiment time:
get an ice cube
touch it for 2 seconds (one thousand one, one thousand two, brr!)
then put saran wrap around it and touch it again. Does it feel just as cold? The plastic wrap has a heat xfer coeff of about 0.30-0.50 or so, but it's pretty damn thin... so it doesn't stop the heat flow into the ice.

wow, but still better than stainless. Where did you get those values? My heat transfer book doesn't have those (I think)

I sprayed a very light misting of Krylon flat black over the I/C, the end caps and the mounting hardware to take away from the shine and make it more stealth. I really don't think it hurt more than a layer of road dust.

I did not, however, remove the overspray on one side of the mouth which is the subject of constant harrassment.

I'll be doing a very light mist of flat black on my saab, just because I don't want to "show off" a 9" wide FMIC, lol.

i just googled and ended up at engineeringtoolbox.com

Even if you paint it, its not like the paint is going to permiate the entire thickness of the core. Spray a thin coat of radiator paint at an angle so you don't get any drips down inside the fins, and the effect should be near zero.

Although to be honest, as low as the miata air intake area is, and shrouded by the bumper, I think its kind of rare for anyone to notice whats inside.

The thing about spray paint and most paints is that it acts as an insulator. Factory intercoolers are usually powder coated, which does very little to the heat transfer coefficient because it actually bonds with the metal. The government did a lot of research for these kinds of things for the reactor plants that are in the submarines. I can't give out any more specifics for the tests, but painting is definately worse. A very light powder coat is very acceptable for the standards, and that is why everything is "supposed" to be powdercoated on the sub.

yeah, i mentioned that above... it's just thin so it doesn't really matter. even aluminum can be an insulator if its thick enough.