Double Intercooler Discussion

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With that said, I don't believe that it would be too much of an issue when compared to the shroud / no shroud issue. Ideally someone who has a car with a tuner and/or logger should get some hard numbers with a DIC both with and without a shroud.
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As I mentioned earlier, I've already done this with my car :cool:.

Fraser
 
That's what kind of has me confused. A theoretic black object does not emit anything, it absorbs all radiation. Highly polished metals tend to reflect radiation. Since we are not talking about reflection, I don't fully understand how that impacts the IC.

This gets a little confusing when we observe black objects in real life. Black objects absorb the sun's radiation. This in turn heats them up. Then they in turn emit their own radiation, but it seems to me that emissivity relates to the reflection and absorption of radiation, not exactly heat transfer.

It seems to me that emissivity is either not well explained or not well understood.

to steal a quote from a physics forum:

"Black objects are black because almost all the light that falls on them is absorbed into the material. Little or no light is reflected back toward your eye, therefore you see black. That light that is absorbed ultmately becomes heat.

White objects are white because almost all the light that falls on them is reflected by the material. Because all the light is reflected back toward you eye, you see white. Little light is turned into heat."

A black object will absorb much more incident light (energy). The absorbed energy has to go somewhere, hence it is turned into heat (energy).

Full discussion

Emissivity has to do with the radiation of energy (in all things, you, me, our cars, etc...) Wiki page on Stephan-Boltzmann Law and emissivity
I'd be glad to answer any other questions you may have (to the best of my ability, might have to dust off ye olde' textbooks ;) )

As I mentioned earlier, I've already done this with my car :cool:.

Fraser

Thanks, I wasn't aware of that. I'll have to do a search later and see if I can dig up any numbers.
 
Look at it this way. The EEC shuts off the cooling fan when the car hits 47mph. This way the air can flow through the rad without the fan restricting it. Now look at much that fan can flow compared to the little 8" and I think you can get the idea.

Fraser

I've heard that the MegaSquirt controller will keep an intercooler cold. Not only that, Casey (Cmac89) told me that the 12 disciples all used it.


:p
 
Yes a black paint will help in emissivity due to radiation. What is more important to look at (in my mind) is the effects of any paint on the intercooler core that may or may not effect the heat transfer via convection (mass air flow through the core). When running the numbers for heat radiation on the intercooler considering the temperatures and tiny surface area the amount of heat lost is pitifully small.

That's a very good point about paint clogging the fins. According to the link below, thinner paints are used for this purpose.

http://www.eastwood.com/underhood-engine/engine-paints/eastwood-radiator-black-paint.html
 
I think I'm getting my mind around the concepts. If I understand this correctly, aluminum is in general a poor emissitor and polishing makes it worse. But, emission is not a primary cooling property of the intercooler. The intercooler relies on convection rather than emission to remove heat and in this sense, aluminum works very well because it carries heat very quickly to it's surface for removal by moving air.

Back to the emissary function though, aluminum would seem to be a less than ideal material for IC tubing, at least the tubing that goes from the blower to the IC. Since little or no air is flowing over the tubes inside the engine bay, it follows that a material that emits heat would be prefered. Now on the return from the IC, it would conversely be prefered to have the tube made of, or wrapped in, a material that would reflect heat, such as aluminum foil wrapping or simply a highly polished aluminum or chrome tube.
 
I found these..

Could you repost your numbers here. I know you have done it but cant find your numbers

Ken

http://www.sccoa.com/forums/showthread.php?t=107912&highlight=shroud
no shroud on the single IC... and I removed the shroud from my DIC and got better cooling.

The biggest problem with the shroud I'm thinking now is not so much the shroud but the lack of fan. Those little 8" fans don't exactly move alot of air, and with the shroud on the only thing moving air through the IC is the fan, even at high speeds. Triple the flow capacity of the fan and it might be a viable option, but until then, you need to rely on the negative pressure on the engine side of the IC/DIC to move the air through them, and the shroud defeats that.

Fraser


http://www.sccoa.com/forums/showthread.php?t=108305&highlight=shroud
Already did and datalogged it... once the car got up over 40mph my ACT's started climbing alot more with the shroud on than off.

Shroud on, pass the big end with ACT's at 156F, ACT's where not leveling off until 80mph.
Shroud off, pass the big end with ACT's at 135F, ACT's where leveling off at 70mph.

This tells me the shroud was blocking the air flow at higher speeds and the fan was insufficient to keep up, and in fact could have been blocking air flow. I've made a huge effort in directing air flow into the DIC and am running a shorter a/c condensor. I didn't say not to run the fan, and it is needed at low speeds.

Fraser
 
I'd say that, and a method of using flaps on the shroud that open up once the pressure builds up enough.

Fraser
 
Is there any room to move the IC closer towards the bumper to maybe install a shroud that is not right up against the IC? Sorry but I have never really looked at the room that is there and will be buying a different IC soon.
 
If someone really wants to pursue a film that would cut down on radiant heat absorbtion to apply to the lower IC tube from the IC to intake, "CDOC" in their catalog sells a Gold Foil Film. They claim it is capable of reflecting 78% of all radiant heat with a continuous operating temperture of 450 degrees C. The only problem is the price which for a 2' X 1' foot section is $33 a running foot. But the gold color inside the engine bay may look cool....could also look ricer but if it work who cares. Minimum air gap from the heat source is only 1mm.
 
Just to throw something out there. The paint only covers the front and rear side of each tube. It also only covers the edge of the fins between the tubes. If I was guessing I would say paint only covers 20% of the cooling surface. There is no paint or coating between the tubes and the heat transfer is more from the thousands of tiny fins between the tubes carrying the air. So is the paint or powder coating really a big deal??? It easy to say the paint inhibits heat transfer but the front and rear surface on the IC is not near as large as all the surfaces between the tubes. Any thoughts on that?


Ken
 
Sorry to raise this from the dead but has anybody figured out how to have an ic fan come on with the key and shut off at speed (47mph). I have racked my brain on configurations of normally opened relays, normally closed relays, parallel, series, lo speed fan signal, hi speed fan signal and I just can't come up with it. I keep coming back to the VSS but I don't know how to use that to control a relay?

On the other hand, this thread is 6 years old when I believe the permacool 8" fan was rated considerably lower than 2400 CFM. The more efficient fan may be able to overcome the pressure differential when the car is at speed?

Looking for recent experiences and or data. I have a DIC with shroud and just trying to decide the best way to wire it up for all around performance highway/city.
 
I agree

While black certainly dissipates heat better than any other color, any coating at all also provides an insulating effect. Any coating is going to interfere with the heat transfer from aluminum to air.

To demonstrate this effect, touch a plain aluminum radiator on a car that is running at operating temperature. Now touch one that is coated. Or - Touch a polished SC top after a hard run, now touch one with a coating on it....

In each case the actual temperature recorded by a contact probe will be roughly the same, but you'll burn your hand a lot quicker on the bare aluminum. Bare aluminum = highest heat transfer rate.

If I were to guess I'd say the most likely reason Ford painted the IC in the first place has to do with corrosion protection and/or cosmetics.

This is correct. Paint only helps prevent corrosion. But can also accelerate it. Hurts heat transfer always
 
In my experience on my SC, the DIC (as well as the radiator) is aided by removing the A/C condenser. It blocks the flow in front of both. Mind you, the A/C needed to be recharged on my car, so A/C was of no real use to me, anyways. I had wrapped my lower IC tube with header wrap, and it keeps it much cooler than it originally was. On super hot days, it still gets a fair bit heat soaked from ambient heat (mostly from idling and lower speed daily driving), but engine bay heat doesn't seem to affect it as much. I had wrapped the whole length of the tube, too.
 
once i ditched the condenser and had in my new 3 cre all aluminum ebay rad it ran so cool at 1st i thought my needle was off but it was really cooling that well..it was mid80'sto90's...
 
Or...there is always the narrow width parallel flow condenser option for those that like their A/C ;)

I have my windows down most of the time in summer, and also am usually rocking a fully opened moonroof. :D
 
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