Radiator

[KevinBoosted]

Just dusting off some final details on my radiator setup, but im curious to what you other track lovers are using. Im using a Mishimoto right now but honestly im not too impressed and at the moment im leaning toward a PWR because of the dual pass design. With that i would hope to see some kind of a drop in temps. I also have a fresh set of FAL fans in a shroud waiting to be mounted on to something new If i were to choose it would be between these 3 at the moment...

-PWR
-Koyo
-Fluidyne

 

[Scott McIntyre]

If you goal is to lower engine temps, in my experience proper ducting is the most effective solution.

I tried installing a thicker all-aluminum radiator... made no difference. I tried installing an air-oil cooler... made no difference. Then I got smart and completely sealed the space between the FMIC & radiator with foam and aluminum tape... Presto! No more overheating. PICS

So my advice would be to start there, then if need be look at radiators & oil coolers.

 

[ramsack]

those aluminum radiators don't offer much cooling over stock ones. i'd stay with stock because black radiators also help get rid of heat more effectively. as scott said, air getting to the rad is the limiting factor. you can get a radiator double the thickness of stock for instance but if air isn't getting across it, it isn't cooling any more. if you still need more then get an aluminum aftermarket one and paint it black (just enough to cover it, not too thick) to make it better.

 

[Calan]

...because black radiators also help get rid of heat more effectively.

Why is this?

 

[ramsack]

black radiates heat better than white. haven't you ever seen those light bulb type things with a rotating "fan" inside with pieces that are black on one side and white on the other? if you put it near a regular incandescent lamp that emits heat it will start rotating with the black side "pushing" heat off of itself. just because a black car gets hotter inside than a white car doesn't have anything to do with a material itself shedding heat. the black is absorbing and radiating the heat, where the white is just simply reflecting it

i looked around, they are called crookes radiometers.

Solar Radiometer - fun educational thermodynamics demo | Edmund Scientific
YouTube - Crookes Radiometer

 

[Calan]

Radiators cool by heat transfer (convection)...not by radiation. The only way the color would matter if is if the radiator is exposed to sunlight, in which case there would be some difference in how much infrared heat is absorbed or reflected.

Factory radiators are painted for corrosion resistance.. They use black because it is a neutral color and it looks good in any engine bay, regardless of the car's color. Otherwise, they would have to stock different colors which isn't cost effective.

If anything, painting an aluminum radiator any color will hinder it's cooling ability by insulating it and lowering it's ability to transfer heat to the air flowing over it.

 

[ramsack]

yes it uses convection internally, but it also radiates heat from it externally, hence why it's called a radiator. it has to get rid of the heat outside somehow. there is nothing outside to convect. if you paint a thin layer of black on it, the side of the paint that touches the radiator will absorb the rad's heat and the other side will radiate the heat from itself. why do oems color their radiators black then? why are aftermarket oil coolers black? i'm not saying it's going to magically make a huge difference, but it's something to try to squeeze the most out of the cooling system.

 

[Killerclipse]

If anything, painting an aluminum radiator any color will hinder it's cooling ability by insulating it and lowering it's ability to transfer heat to the air flowing over it.

I can't remember who it was, but I do know that they did a test with intercoolers by powder coating them to see how it affected the temps. It had almost no impact on the temps. That is for an intercooler though.

 

[ramsack]

powder coating is usually laid on thick, this is probably why it had no effect, because it was insulating. if you scratch the paint on a stock radiator it will scratch fairly easily and show you how thin they painted it.

 

[Calan]

yes it uses convection internally, but it also radiates heat from it externally, hence why it's called a radiator. it has to get rid of the heat outside somehow. there is nothing outside to convect. if you paint a thin layer of black on it, the side of the paint that touches the radiator will absorb the rad's heat and the other side will radiate the heat from itself. why do oems color their radiators black then? why are aftermarket oil coolers black? i'm not saying it's going to magically make a huge difference, but it's something to try to squeeze the most out of the cooling system.

But...thermal radiation is wavelength dependent. Here's a fairly decent wiki article that I just found:

Thermal radiation

"If objects appear white (reflective in the visual spectrum), they are not necessarily equally reflective (and thus non-emissive) in the thermal infrared; e. g. most household radiators are painted white despite the fact that they have to be good thermal radiators. Acrylic and urethane based white paints have 93% blackbody radiation efficiency at room temperature[4] (meaning the term "black body" does not always correspond to the visually perceived color of an object). These materials that do not follow the "black color = high emissivity/absorptivity" caveat will most likely have functional spectral emissivity/absorptivity dependence."

Regardless of that, as you and others stated... maximizing airflow over the radiator will improve it's efficiency MUCH more than anything having to do with it's color.

 

[ramsack]

and that is also at room temperature. where does it cite the blackbody efficiency of black? this argument can go on forever and delve into quantum physics with black body stuff. stuff that isn't understood fully by scientists and he we are arguing about it.

i think later i will test these with a water cooling setup for a pc that i'm not using anymore. i believe my radiators are uncoated, so i will test bare, black, and white. i will heat up the water block to a certain temperature and then turn the pump on and see how long it takes to get down to a room temperature. trying to understand something that physicists still are is still not as real as results.

i never knocked airflow either. in my first post i suggested that as the first thing to do. i then said it couldn't help putting a thin layer of paint. i also said it will probably make a very tiny difference if you can even measure it.

 

[Calan]

and that is also at room temperature. where does it cite the blackbody efficiency of black? this argument can go on forever and delve into quantum physics with black body stuff. stuff that isn't understood fully by scientists and he we are arguing about it.

i think later i will test these with a water cooling setup for a pc that i'm not using anymore. i believe my radiators are uncoated, so i will test bare, black, and white. i will heat up the water block to a certain temperature and then turn the pump on and see how long it takes to get down to a room temperature. trying to understand something that physicists still are is still not as real as results.

Well most every-day objects aren't necessarily true "black bodies" in the physics sense of the word.

That would be really cool if you can do those tests. I'm interested to see what the real world results would be, assuming you can keep everything on an even playing field without too many variables.

i never knocked airflow either. in my first post i suggested that as the first thing to do.

I know...that's why I said:

Regardless of that, as you and others stated

 

[ramsack]

we can argue about this forever. but who wants a white radiator on their car vs. a black one? i think maybe copper plating would be better than the paint?

 

[UofACATS]

I will be using the oem unit until it proves inadequate. I still use the oem fans as well. They work.

Any radiator will prove inadequate without proper ducting and/or inadequate airflow.

If you goal is to lower engine temps, in my experience proper ducting is the most effective solution.........So my advice would be to start there, then if need be look at radiators & oil coolers.

This is your answer.

Can't wait to see you out there..

 

[ramsack]

and i also see a lot of people just slap those aftermarket kind of spal fans right on the radiator with no shrouds and have overheating problems.

 

[KevinBoosted]

I will be using the oem unit until it proves inadequate. I still use the oem fans as well. They work.

Any radiator will prove inadequate without proper ducting and/or inadequate airflow.

This is your answer.

Can't wait to see you out there..

Haha hey Noah!
I agree, I've been working on some ducting but until I get a new bumper I'm at a halt right now. I was using the stock fans but the size of the 3065 gave me no option but to get slim fans. No worries though, its coming along....slowly

 

[95blackGsTurbo]

Stock radiator with some good strong fans will work nicely. I can grab some from work for you for a good deal. Either that or call Ron Davis Racing. He is local and does work that is just insane.

 

[KevinBoosted]

Stock radiator with some good strong fans will work nicely. I can grab some from work for you for a good deal. Either that or call Ron Davis Racing. He is local and does work that is just insane.

I already have a set of FALS, but thanks anyway Adam

those aluminum radiators don't offer much cooling over stock ones. i'd stay with stock because black radiators also help get rid of heat more effectively. as scott said, air getting to the rad is the limiting factor. you can get a radiator double the thickness of stock for instance but if air isn't getting across it, it isn't cooling any more. if you still need more then get an aluminum aftermarket one and paint it black (just enough to cover it, not too thick) to make it better.

Im not sure if this is true. Kirschoff's Law states that an object absorbs radiation at a given wavelength and emits it at the same wavelength (i.e.- a highly polished, light color surface absorbs little energy and, in turn, emits litter IR energy. In contrast, a black surface absorbs high levels of energy and emits a larger amount of IR energy. This would also explain why if your car does wot pulls and comes to a stop, you would be able to place your hand on the surface of a polished radiator with little to no effect, but if you did it to an oem core you would burn your hand

Kirschoff's Law would also apply to FMICs then. Explaining why most to all Intercoolers are light colored or polished surfaces

 

[KevinBoosted]

So any input on any of the 3 radiators...anyone?

 

[Ludachris]

My two biggest impacts on cooling for my car at the road course was a thicker than stock PWR radiator and a hood vent. Now just need some ducting.

 

[CrankWalkerX99]

So any input on any of the 3 radiators...anyone?

Why is the Mishimoto not "impressing you"? Is your car overheating or something? You are essentially taking out a radiator that has a lifetime warranty (with accident protection.... ask me how I know ), to replace with another aluminum radiator... that might not come with a warranty that lasts longer than initial start-up? (depending on which you go with)

Maybe I am just not understanding this correctly?

 

[Flash]

Why is the Mishimoto not "impressing you"? Is your car overheating or something? You are essentially taking out a radiator that has a lifetime warranty (with accident protection.... ask me how I know ), to replace with another aluminum radiator... that might not come with a warranty that lasts longer than initial start-up? (depending on which you go with)

Maybe I am just not understanding this correctly?

Mishimoto is cheap crap. The ones listed are of better build quality and are used by actual real race teams for a reason.

 

[Ludachris]

Why is the Mishimoto not "impressing you"? Is your car overheating or something? You are essentially taking out a radiator that has a lifetime warranty (with accident protection.... ask me how I know ), to replace with another aluminum radiator... that might not come with a warranty that lasts longer than initial start-up? (depending on which you go with)

Maybe I am just not understanding this correctly?

I think cooling is going to be more important to people in this specific forum than crash protection and lifetime warranties. Is the Mishimoto the best radiator a DSM road racer can use? I would think that any radiator that is the same dimensions as stock will not be the best option for racing applications. Unless Mishimoto makes a thicker version for our cars, I would say PWR is the better option.

 

[snowborder714]

The Koyo is the thickest radiator made for a 2g I believe. I know it's thicker than the Fluidyne, but don't know the size of the PWR one.

I have a Koyo and like it. Coupled with a set of dual Flex-a-lite fans and a Dakota Digital fan controller, my car rarely gets above 180*.