Guys with headers... first of many header questions.

[2010 4 DW]

Originally Posted by Badbubba

You are correct that the coated headers not give off as much heat. One reason is the "shiny" surface. It will not radiate as much heat, this is due to a low emissivity of the coating. But as for the temperature difference between the two header's surface temp, it depends on how you measured the temperature. If you used a contact device, such as a thermometer or thermocouple, no issues. If you used a point and shoot infrared temp gun without adjusting the emissivity for each surface, then the temp values could be skewed. Especially if the uncoated headers had a few hrs on them.

I used a Pyrometer when I did my testing and both sets were with the car running at idle for five minutes. The ceramic set was coated inside and out also.

[evilbeef54]

Originally Posted by newagemuscle

Looks really cool with the yellow sleeves. I may go that route or a whole new wire altogether. I would really like yellow wires considering I have a yellow car; however, I have not seen any in yellow. If not, I will probably just get red.

i have seen yellow wires in the past, not sure if anyone still makes em, or the preformance of them, the sleeves look nice and were cheap, win win

[Badbubba]

Originally Posted by 2010 4 DW

I used a Pyrometer when I did my testing and both sets were with the car running at idle for five minutes. The ceramic set was coated inside and out also.

Some of those allow you to adjust the emissivity, others no. If the uncoated headers were new/polished when you measured the temp, then I'd say the temp difference between the two is fairly accurate. If the uncoated headers were not polished and were on the car for awhile, allowing the surface to change, then the temp difference would not be representative. In other words, different surfaces give off different amounts of infrared energy at the same temperatures and the pyrometer measures that amount of "energy" (acutally it measures amplitudes/frequencies in a fixed wavelength spectrum). A "shiny" surface will give off less IR energy (radiation) than a corroded surface. Thus, if you heated up an old header and a new shiny one to the same temp, the pyrometer would display a lower temp for the new shiny one. Emissivity is the correction factor for different surfaces. I know a few people who did a case study with Jet Hot coatings, well worth it. To sum it up, go with a coating.

[sschevybear11]

I love me some coated dynatechs. they stay pretty.

[Moreno1]

Originally Posted by mlee

Kooks and ARH are not polished. Polished looks like chrome and it does still look great over time.. They will have a little discoloring right at the heads but not bad at all. We have quite a few sets on in our Camaro club and a lot of the big shops here are using them.

So are you say that if you get your headers polished, they way stay that way longer?