From my air-cooled tuning experience, we would paint the finned cylinders FLAT BLACk to add heat radiation abilities. Some guys would even blacken the cooling fins on their cylinder heads to aid cooling. I have never tested the difference in cylinder head temperature (depends on mixture, ambient temp, RPM [fan output on Porsche or VW], and load among other things), but since we were getting nearly 100hp per liter normally aspirated, we did whatever we could to aid cooling.
Anyway, I was thinking that painting the intercooler FLAT BLACK would aid slightly in its ability to cool the intake charge. Coupled with a water spray and STi scoop......anybody try this yet?

 

um......doesn't black absorb heat?
having a reflective surface (i.e. metal).....would reflect heat, yes

 

Originally posted by jimr
From my air-cooled tuning experience, we would paint the finned cylinders FLAT BLACk to add heat radiation abilities. Some guys would even blacken the cooling fins on their cylinder heads to aid cooling.
I thought about it recently and did some Google research on painting engine components flat black. What some folks found was that the difference was negligible. They said that the only significant difference was when the engine part was exposed to sunlight, the result being more heat absorbtion on black-painted surfaces. We already knew that from comparing black cars and white cars parked in the sun.

Prior to this, I'd read that painting engine parts with a non-insulating (can't find such a thing using Google) flat black paint allows greater heat transfer to the surrounding air, and that aluminum parts could be anodized flat black for the same effect. Engine block interior surfaces would be carefully painted with Glyptal. Conversely, intake manifolds were sometimes polished to prevent radiant engine heat from being absorbed by the slightly cooler manifold (by the intake charge of air and gasoline from a normally aspirated engine). Same goes for chrome plating and header wrap tape on exhaust to provide insulation that retains heat inside the system where it does the most good.

Now that I'm thoroughly confused, I think that I will leave the intercooler unpainted. My thinking is that any paint coating will act as an insulator against heat transfer to the air. I think your STi hood scoop (with some sort of splitter/seal) and water sprayer will probably get as much efficiency as is practical from the OEM intercooler.

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"…axles of evil…" - george w. bush

 

There is only one coating that I am aware of that is specifically made for Intercoolers. Swaintech. Look em up.. They also have some trick coatings for exhaust products and your valvetrain.