paint it and install a water sprayer system...

that way you can have 2 things to argue about on the internet

 

^ hahah

 

Sorry that I don't have time to read all of the posts... on a tight crunch here. But a few things I'll toss in that might back up or contradict things already posted....

Painting the intercooler fins will drastically reduce efficiency because you are adding to the radiated heat that the IC is picking up (This is a function of Temp to the FOURTH degree!), and you're also cutting down on the airflow. If you put a thin coating on a pipe, you don't reduce much area-wise, but putting paint on fins with a small gap will definately change the area. Think of applying the paint and lowering the size of your bedroom, vs painting the cathode on a standard spark plug and the effect on Gap.

Also, painting the end tanks won't reduce as much, but I saw emissivity mentioned. That could work if the pipe was radiating the heat, but the pipe is actually picking up the heat. You want to keep the color as reflective and light as possible.

My .02 is that you don't want to make it darker, because it will ABSORB more heat, and you don't want to close the gap in the IC fins because it will lower the flow of ambient, cooling air to the IC.

Hopefully that helps, and like I said I didn't read all of the posts.

 

Alright, I've finally read all of the posts here after picking up the wife's car (also a mazda, so don't flame me!). Dave, this post seems to be kind of a culmination of what all of the others say.

There are THREE methods of heat transfer. There's conductive and radiated, which Dave mentioned. There's also Convection (think of a convection oven) where heat is transferred by a medium moving it from one surface to another non-touching surface. Convective heat is how most gets transferred in engine compartments, and also how most is attempted to be evacuated.

An IC is trying to take heat that is picked up from the turbo and dissipate it with amient air through convection. The heat picked up by the IC comes from all three types. Now this is the important part that can explain the contractiction earlier in the thread....

ENERGY IS TRANSFERRED FROM HIGH TO LOW POTENTIAL

That means that hot objects (high energy) transfer to cooler objects (low energy). Think of this in terms of wearing a white vs a black shirt on a sunny day. Does the black shirt by ANY means help you stay cool? Here's a definition of "emissivity" that I found with a quick google that puts it in perspective...

"A mirrored surface may reflect 98% of the energy, while absorbing 2% of the energy. A good blackbody surface will reverse the ratio, absorbing 98% of the energy and reflecting only 2%."

Notice that painted black will absorb 98% in a strongly emissive surface. This is the opposite of what you want from an IC, so clearly the highly emissive finish is not what you want.

Also, the trend with painting radiators and available products to do it does not mean that it increases effectiveness. The reason I could see the radiator paint having more of an effect would be the the temp difference between the radiator and engine bay is small compared to (hopefully) the IC and engine bay. A smaller delta in temperature can lead to a HUGE difference in radiated susceptablilty.

Remember that radiation is a function of T^4, so if there is twice the difference in temp between the Rad/Eng as there is between IC/Eng, you have 16 times the amount of energy absorbed in the IC as you do the radiator. If you have a bigger difference, say 3 times, that number jumps to 81 times the energy being transmitted to the IC vs what the radiator will see from radiated energy alone.



Pretty much all of that is to say that from a heat transfer standpoint, NO, do not paint your IC. If anything, make it brighter, lighter, and more reflective. This will give you the best rejection of engine bay heat to the intercooler and allow it to work more efficiently. Think of painting an IC as moving it further into the engine compartment. I see a black IC as being placed touching the exhaust, and a highly reflective IC as being placed in front of the bumper for a drastic way to explain it. Again, just my .02, but hopefully it gives more insight without being too "nerdy"

 

i would think that from what Bell Intercoolers says would be right, since they are a IC manufacturer i would think that they would have done some sort of testing, and they said it the loss of performance of the IC wouldnt be measureable

 

i thought about using the radiator paint and just like spraying like 2 feet away from the ic so that it was a very very fine mist and get just enough to tint the surface not make it black... i'll prolly never do it though i'll wait for someone else to do it!

 

I get the feeling that they tested it in terms of pressure drop over the IC, not in long-term tests of if painting it black would change the heat soaking characteristics of the IC core.

 

Convection just conduction between a solid and fluid. ;o)

Dave

 

This whole thread is a bunch of BS.
Everyone ignored my first post. UNLESS YOU ARE SPRAYING A LARGE AMOUNT OF THICK PAINT INTO THE CORE, then you will not affect anything. Heat transfer occurs inside the core on the large surface areas within the core, NOT on the little bit you can actually see by looking at the front of the core. Simply painting the visible surface of the core (intelligently) will not change anything. Many OEM intercoolers from other manufactureers are painted. NOT DIPPED INTO PAINT. Get real.

 

One thing you'll learn about this forum, is that they over analysis everything.

 

I for one did not make that assumption, and a few folks here didn't either.

If we restrict this idea to painting the visible surfaces of the fins, then I agree it's insigificant. That is more in line with the OP's goals too.

Dave

 

Then what was the purpose of all those Einstein type theories?

 

Einstein??. It's intro heat transfer. Engineers think about this kind of stuff all the time.

The discussion as I saw it revolved around a what-if where the whole IC was a different color. Whether it's practical is the second step to working with an idea.

Dave