Pettit Super Charger Owners
08-01-2010, 09:34 AM
#7526
Tailgaters beware
That is a myth most recently and successfully perpetuated by Jeff Goldblum on "Jurassic Park." The "Black" in "Black-body radiation" has nothing to do with paint but describes an ideal "thing" that reflects no light, absorbs it all, then emits this energy as light without doing any other work to generate a specific spectrum of light that is temperature dependent. When it is cold, it would be perfectly black. As it warms up, the spectrum has characteristics that are important in theoretical ways.
THIS DOES NOT MEAN THAT BLACK THINGS ARE COOLER. IN NO WAY SHAPE OR FORM!! THE "BLACK" IN "BLACK-BODY RADIATION" IS BLACK BECAUSE IT IS NOT REAL, but ideal. It is absolutely NOT a rattle-can painted, ghetto-stealth fronting, big-*** IC.
Sure, there are ways to coat things that could lead to more thermal emission, and those coatings might be black, but it has nothing to do with the "black body effect."
[/edjumacative rant]
THIS DOES NOT MEAN THAT BLACK THINGS ARE COOLER. IN NO WAY SHAPE OR FORM!! THE "BLACK" IN "BLACK-BODY RADIATION" IS BLACK BECAUSE IT IS NOT REAL, but ideal. It is absolutely NOT a rattle-can painted, ghetto-stealth fronting, big-*** IC.
Sure, there are ways to coat things that could lead to more thermal emission, and those coatings might be black, but it has nothing to do with the "black body effect."
[/edjumacative rant]
Car radiators are painted black because it emits the most heat through radiation (highest emissivity). This improves the heat transfer out of the radiator when air isn't moving through the radiator. -WikiAnswers
"black color = high emissivity/absorptivity" - http://en.wikipedia.org/wiki/Thermal_radiation
So when your fan is not running and you aren't moving black does help to dissipate heat. I don't know if painting the IC is adequate, but that is what the automobile manufacturers do with radiators. -Me
Emmissivity = The emissivity of a material is the relative ability of its surface to emit energy by radiation. It is the ratio of energy radiated by a particular material to energy radiated by a black body at the same temperature. It is a measure of a material's ability to radiate absorbed energy. -Wikipedia
Wikipedia http://en.wikipedia.org/wiki/Emissivity
WikiAnswers http://wiki.answers.com/Q/Why_are_ca..._painted_black
08-01-2010, 09:42 AM
#7527
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I am not so sure I would put a lot of faith in an answer out of wikianswers. Same might be said of a post in RX8club.
I am not going to disagree that a non-black object will have less thermal emissivity than an black object. That is not what I am disagreeing with. What I am taking issue with is the idea that the theoretical construct around "Black-body radiation" somehow implies that you standing out in the sun will be cooler wearing a black suit, or that painting an ic will somehow make it shed more heat because neither is true.
I am not going to disagree that a non-black object will have less thermal emissivity than an black object. That is not what I am disagreeing with. What I am taking issue with is the idea that the theoretical construct around "Black-body radiation" somehow implies that you standing out in the sun will be cooler wearing a black suit, or that painting an ic will somehow make it shed more heat because neither is true.
08-01-2010, 10:13 AM
#7528
Tailgaters beware
I am not so sure I would put a lot of faith in an answer out of wikianswers. Same might be said of a post in RX8club.
I am not going to disagree that a non-black object will have less thermal emissivity than an black object. That is not what I am disagreeing with. What I am taking issue with is the idea that the theoretical construct around "Black-body radiation" somehow implies that you standing out in the sun will be cooler wearing a black suit, or that painting an ic will somehow make it shed more heat because neither is true.
I am not going to disagree that a non-black object will have less thermal emissivity than an black object. That is not what I am disagreeing with. What I am taking issue with is the idea that the theoretical construct around "Black-body radiation" somehow implies that you standing out in the sun will be cooler wearing a black suit, or that painting an ic will somehow make it shed more heat because neither is true.
I am thinking of anodizing an IC not painting.
I would agree that it is much hotter in a black shirt than in a white one when standing in the sun.
When it comes to natural color I have a different opinion. I understand that creatures or people's bodies are adaptive to their environment. What I want to use as an example is Africans having darker color skin than say a native of England. Africa is a very hot country, and at some point in ancient history, the natives have adapted to that climate by a darkening of the skin.
Perhaps the "black" draws the heat from the core to the surface to cool the organs, since the organs functionality are much more important than having cool skin. With an IC that may be helpful since the air is in the core.
08-01-2010, 10:51 AM
#7530
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When it comes to natural color I have a different opinion. I understand that creatures or people's bodies are adaptive to their environment. What I want to use as an example is Africans having darker color skin than say a native of England. Africa is a very hot country, and at some point in ancient history, the natives have adapted to that climate by a darkening of the skin.
Perhaps the "black" draws the heat from the core to the surface to cool the organs, since the organs functionality are much more important than having cool skin. With an IC that may be helpful since the air is in the core.
Perhaps the "black" draws the heat from the core to the surface to cool the organs, since the organs functionality are much more important than having cool skin. With an IC that may be helpful since the air is in the core.
The adaptation of increased dermal melanin is a pretty well known phenomenon. I wonder if you went to school in the US? The US seems to pride itself with purposefully NOT teaching its children science so that it can protect them from the evils of Darwinism and Evolution. You know, so as to not undermine the Christian underpinnings of civilization.
In anycase, it has nothing to do with heat.
ETA: I am sorry for sounding like an *** or being condescending. That was not my intent (tho I am a bit of an ***.) I will let the post stand as is so as to allow for any interesting riposte.
Last edited by carbonRX8; 08-01-2010 at 10:56 AM.
08-01-2010, 11:09 AM
#7531
you are exactly right. you know the modern day odd thing concerning that?
Up to 33% of all teenagers are not getting enough vit D due to lack of sun exposure. Of coarse darker colored people are more prone to that.
Get your kids in the sun some. Esp teenage girls --not only does this help combat anemia but also later bone growth.
OD
Up to 33% of all teenagers are not getting enough vit D due to lack of sun exposure. Of coarse darker colored people are more prone to that.
Get your kids in the sun some. Esp teenage girls --not only does this help combat anemia but also later bone growth.
OD
08-01-2010, 12:05 PM
#7532
Tailgaters beware
Nope. The increased melanin you see in peoples aboriginally in more equitorial latitudes is an adaptation that decreases skin cancer. The melanin absorbs the UV so your DNA doesn't. The reason folks in higher latitudes do not have this coloration is thought to be an adaptation to increase light absorbtion so as to process vitamin D into its usable form.
The adaptation of increased dermal melanin is a pretty well known phenomenon. I wonder if you went to school in the US? The US seems to pride itself with purposefully NOT teaching its children science so that it can protect them from the evils of Darwinism and Evolution. You know, so as to not undermine the Christian underpinnings of civilization.
In anycase, it has nothing to do with heat.
ETA: I am sorry for sounding like an *** or being condescending. That was not my intent (tho I am a bit of an ***.) I will let the post stand as is so as to allow for any interesting riposte.
The adaptation of increased dermal melanin is a pretty well known phenomenon. I wonder if you went to school in the US? The US seems to pride itself with purposefully NOT teaching its children science so that it can protect them from the evils of Darwinism and Evolution. You know, so as to not undermine the Christian underpinnings of civilization.
In anycase, it has nothing to do with heat.
ETA: I am sorry for sounding like an *** or being condescending. That was not my intent (tho I am a bit of an ***.) I will let the post stand as is so as to allow for any interesting riposte.
I did go to school in the US but that was 17 years ago so I don't remember whether they "tried" to teach me that or not. I went to college for Business Management but my courses wouldn't contain anything involving aborigines or melanin.
Are you by any chance in Australia?
Any way, here is what I found about black vs lighter colors.
First, skin color. While dark skin is better protected from ultraviolet radiation, it does absorb more of the energy in visible light than light skin. But most of the sun's heat comes in invisible infrared radiation. Dark and light skin are the same color in that range. Dark skin absorbs no more heat than light skin does -John H. Lienhard, University of Houston
http://www.uh.edu/engines/epi1149.htm
Last edited by Rocketman1976; 08-01-2010 at 01:17 PM.
08-01-2010, 01:35 PM
#7533
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Ah, a rational conversation. Who'da thunk it.
I was considering emissivity over lunch and trying to get a ball park figure of how much energy that could be shed by an ideal body at 100-110 degrees C and then compare that to the energy removed by standard convective processes, i.e, air through the radiator while moving. In other words, how much energy could we reason could be shed by irradiative processes and would changing that quantity by a fraction by changing the emissivity make much of a difference.
I was not able to come up with a formula to account for non-irradiative or convective shedding. I am not even sure that there is a formula to account for it. I could come up with a rough number by just assuming that the engine runs at steady state and that the energy released as heat when not doing work is the energy released by by the gas that is burnt.
The number, which I am not sure is correct, for irradiative processes is 1/1000th of that (with a LOT of assumptions.)
I think that this can be visualized easily by considering a metal cup of tea. A cup of tea can stay warm for quite a while if completely undisturbed by droughts or stirring. This is because the only process that is releasing the heat is by irradiation. However, if you put this cup in front of a fan, it would cool quite quickly. Same goes of putting your hand above a oven coil on hi. You can get pretty close and not get burnt, but put a fan behind this, such as through a hair drier (a much lower power than the oven) and you can burn yourself quickly.
I just dont think irradiative processes matter much in cooling an engine.
No, I live in the US. I have just been kinda studying, offline from my normal work, the anti-intellectual, anti-science tendencies that seem to have become a little more apparent, at least to me, recently. I am considering writing some essays on the topic and put them into circulation. I am convinced that, if these tendencies become more dominant, that this will have serious negative implications for America's standing in many fields.
I was considering emissivity over lunch and trying to get a ball park figure of how much energy that could be shed by an ideal body at 100-110 degrees C and then compare that to the energy removed by standard convective processes, i.e, air through the radiator while moving. In other words, how much energy could we reason could be shed by irradiative processes and would changing that quantity by a fraction by changing the emissivity make much of a difference.
I was not able to come up with a formula to account for non-irradiative or convective shedding. I am not even sure that there is a formula to account for it. I could come up with a rough number by just assuming that the engine runs at steady state and that the energy released as heat when not doing work is the energy released by by the gas that is burnt.
The number, which I am not sure is correct, for irradiative processes is 1/1000th of that (with a LOT of assumptions.)
I think that this can be visualized easily by considering a metal cup of tea. A cup of tea can stay warm for quite a while if completely undisturbed by droughts or stirring. This is because the only process that is releasing the heat is by irradiation. However, if you put this cup in front of a fan, it would cool quite quickly. Same goes of putting your hand above a oven coil on hi. You can get pretty close and not get burnt, but put a fan behind this, such as through a hair drier (a much lower power than the oven) and you can burn yourself quickly.
I just dont think irradiative processes matter much in cooling an engine.
No, I live in the US. I have just been kinda studying, offline from my normal work, the anti-intellectual, anti-science tendencies that seem to have become a little more apparent, at least to me, recently. I am considering writing some essays on the topic and put them into circulation. I am convinced that, if these tendencies become more dominant, that this will have serious negative implications for America's standing in many fields.
08-01-2010, 02:06 PM
#7534
That is a myth most recently and successfully perpetuated by Jeff Goldblum on "Jurassic Park." The "Black" in "Black-body radiation" has nothing to do with paint but describes an ideal "thing" that reflects no light, absorbs it all, then emits this energy as light without doing any other work to generate a specific spectrum of light that is temperature dependent. When it is cold, it would be perfectly black. As it warms up, the spectrum has characteristics that are important in theoretical ways.
THIS DOES NOT MEAN THAT BLACK THINGS ARE COOLER. IN NO WAY SHAPE OR FORM!! THE "BLACK" IN "BLACK-BODY RADIATION" IS BLACK BECAUSE IT IS NOT REAL, but ideal. It is absolutely NOT a rattle-can painted, ghetto-stealth fronting, big-*** IC.
Sure, there are ways to coat things that could lead to more thermal emission, and those coatings might be black, but it has nothing to do with the "black body effect."
[/edjumacative rant]
THIS DOES NOT MEAN THAT BLACK THINGS ARE COOLER. IN NO WAY SHAPE OR FORM!! THE "BLACK" IN "BLACK-BODY RADIATION" IS BLACK BECAUSE IT IS NOT REAL, but ideal. It is absolutely NOT a rattle-can painted, ghetto-stealth fronting, big-*** IC.
Sure, there are ways to coat things that could lead to more thermal emission, and those coatings might be black, but it has nothing to do with the "black body effect."
[/edjumacative rant]
Thanks for summarizing the little bit at the end of my post where I pointed out that "(painting the radiator black) may not have any real effect).
If you want to get physic-all, technically, a black radiator will shed infrared radiation vs. a silver radiator if both have equivalent heat content, in a passive environment. However, place both in a a car, and the "passive environment" is shot to hell. Besides radiating infrared (heat) quicker than a silver radiator, they also absorb radiant IR (from hot engine parts) more quickly. Again, how much this affects operating temps, I can't say without a lot of expensive research that I don't have any interest in conducting. I do know a black car gets hotter in Florida than a silver car; don't know if it also cools more quickly at night either.
In truth, either view of how Black Body affects our radiators is meaningless. If silver or black radiators showed significantly superior cooling potential, then by God, all our radiators would be one or the other. In maintainging focus on the original question at hand about whether painting an intercooler heat exhanger black for a 'stealth' look would be harmful, the answer is a definitive "no", and just for giggles, since it's black, it might passively shed heat faster.
Enough of that crap, pass me a Penthouse, the wideband sensor, and a beer.
Last edited by zenrx8; 08-01-2010 at 02:08 PM.
08-01-2010, 02:14 PM
#7536
08-01-2010, 02:22 PM
#7537
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Just widen the openings on the plastic shroud piece that sits just behind the oil coolers for better/increase airflow at high speed. Not that much since I didn’t want to ruin/alter the properties/strength of the plastic and the ability to prevent loose material to hit the back of the oil coolers. Basically, I trimmed the bottom of each rectangle back to the flush part of the plastic shroud face. Sorry, no before pictures. 
08-01-2010, 03:51 PM
#7541
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Are you saying that you find it sad that RX8 owners want an easy way to lift their car or that it is sad that they want THIS PARTICULAR lift to lift their car.
Because I damn sure wish I had a way to get my car up in the air rather than having use a jack.
Because I damn sure wish I had a way to get my car up in the air rather than having use a jack.
08-01-2010, 05:24 PM
#7545
I divide by zero
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LOL!
When I built my new house the 3rd car stall was intended to have a lift in it. When I started to look at lifts my wife said "Why do you need a lift? Stop breaking your car and you wont need it!"
Still havent gotten my lift
When I built my new house the 3rd car stall was intended to have a lift in it. When I started to look at lifts my wife said "Why do you need a lift? Stop breaking your car and you wont need it!"
Still havent gotten my lift
08-02-2010, 12:19 AM
#7546
Tailgaters beware
Jeff Gold...who? Jurassic Pork? Myth?
Thanks for summarizing the little bit at the end of my post where I pointed out that "(painting the radiator black) may not have any real effect).
If you want to get physic-all, technically, a black radiator will shed infrared radiation vs. a silver radiator if both have equivalent heat content, in a passive environment. However, place both in a a car, and the "passive environment" is shot to hell. Besides radiating infrared (heat) quicker than a silver radiator, they also absorb radiant IR (from hot engine parts) more quickly. Again, how much this affects operating temps, I can't say without a lot of expensive research that I don't have any interest in conducting. I do know a black car gets hotter in Florida than a silver car; don't know if it also cools more quickly at night either.
In truth, either view of how Black Body affects our radiators is meaningless. If silver or black radiators showed significantly superior cooling potential, then by God, all our radiators would be one or the other. In maintainging focus on the original question at hand about whether painting an intercooler heat exhanger black for a 'stealth' look would be harmful, the answer is a definitive "no", and just for giggles, since it's black, it might passively shed heat faster.
Enough of that crap, pass me a Penthouse, the wideband sensor, and a beer.
Thanks for summarizing the little bit at the end of my post where I pointed out that "(painting the radiator black) may not have any real effect).
If you want to get physic-all, technically, a black radiator will shed infrared radiation vs. a silver radiator if both have equivalent heat content, in a passive environment. However, place both in a a car, and the "passive environment" is shot to hell. Besides radiating infrared (heat) quicker than a silver radiator, they also absorb radiant IR (from hot engine parts) more quickly. Again, how much this affects operating temps, I can't say without a lot of expensive research that I don't have any interest in conducting. I do know a black car gets hotter in Florida than a silver car; don't know if it also cools more quickly at night either.
In truth, either view of how Black Body affects our radiators is meaningless. If silver or black radiators showed significantly superior cooling potential, then by God, all our radiators would be one or the other. In maintainging focus on the original question at hand about whether painting an intercooler heat exhanger black for a 'stealth' look would be harmful, the answer is a definitive "no", and just for giggles, since it's black, it might passively shed heat faster.
Enough of that crap, pass me a Penthouse, the wideband sensor, and a beer.
I'm still going with black for the stealth reason!
I don't know if anyone missed this post earlier.
As far as a lift goes, this one is $1300 and you would have much better access. That is of course, as long as your garage is tall enough.
http://www.gregsmithequipment.com/Pr...Code=TP-XL-9BP
Last edited by Rocketman1976; 08-02-2010 at 12:30 AM.
08-02-2010, 05:20 PM
#7547
I think so. PDXHAK shows it worked for him; I did a little eyeballing on mine and believe that the skirts don't go any lower than the regular rear skirts. I think you'd need blocks to keep the car high enoough off the lift to get the rubber blocks in place at the lift points.
08-02-2010, 05:24 PM
#7548
Originally Posted by Rocketman1976
I don't know if anyone missed this post earlier.
As far as a lift goes, this one is $1300 and you would have much better access. That is of course, as long as your garage is tall enough.
http://www.gregsmithequipment.com/Pr...Code=TP-XL-9BP
Last edited by zenrx8; 08-02-2010 at 05:28 PM.
08-02-2010, 05:30 PM
#7549
