http://www.designengineering.com/pro...asp?m=sc&cid=3

Calling all thermal engineers, does this make any sense please ?

 

Well the law of thermodynamics for our turbos state the more heat energy you provide the turbine the quicker the spool and by preventing the heat from escaping the headers via normal convention it will be sent to the turbo instead.
You can also ceramic coat the headers as well for next to nothing or check out fvd website they sell sport headers ceramic for about $1000 on sale.
Ceramic coatings also protect the headers from cracking.

 

I've seen thermal wrap rot headers and other exhaust components before. Best to do the ceramic coating.

 

Definately ceramic coat vs wrapping. The wrap seems to always smell and smoke even after the initial period. Looks really dirty also. For a Porsche driven in the elements, wrap would get water logged. My $0.02

 

wrapping headers and exhaust is not a good idea, as it will hold in moisture and over a period of time rott out the header, comes apart, dirty looking, all of the above as stated, Ceramic is the way to go,

 

I don't consider myself a thermal engineer, lol , but I have been in the header/ceramic coating business for 20 years to date and coat Porsche headers, tips and turbocharger housings on a daily basis..here are some examples of blk and dk graphite oil based ceramic finishes. there are other finishes also available.

 

Headerwrap is ugly but it works fine. One drawback I can imagine is actually doing it on such short runners would be tricky. It will not rust the headers; they are rust resistant (stainless), and they get too hot...any water evaporates! If anything, they will keep the metal more stable as the heat will not be cycling up and down as rapidly. If oily and dirty it looks like crap. If done well it looks pretty good, at least until it gets filthy. Ceramic coating has come a long way but I have never seen a ceramic coated turbine housing that you could touch when the car is operational...I have seen a turbine housing blanket that was touchable after running the car.

 

Hello all, For starters "stainless" does rust as do all metals that is a fact, and has a tendancy to crack under stress. stainless will take longer to rust, but in most cases will last the lifetime of the car. there are header manufactures that will NOT warranty headers that have been wrapped, besides looking horrible, they will hold moisture, more so when the car is not in use and just sitting, they collect dirt, oil, fuel spill,condensation, etc, there is no doubt that header wrap does what it is supposed to do, fight heat but ceramic coating does all the same without the mess, and bulkyness, and you can coat inside your headers,and the flanges the hottest part/area of the header., try that with wrap, when the inside of a header is coated it will help in faster exiting of exhaust gasses,"denser fuel aircharge" and because there is aluminum product in the ceramic that we use, it actually helps dissapate the heat between run(s).faster cool downs. as far as touching a turbo housing after a run, Why? and if you had to work on the housing, time to take off the blanket, yea it's hot under there. plus the ceramic covers the entire housing, the blanket is big and bulky and does not make direct contact on the COMPLETE surface area of the housing . so what have you gained the wrap and the ceramic both can fight temps of 1800-2000 degrees. in the end the ceramic just simply looks better. and it's not any big $ savings. When your done wrapping your headers go wash your hand and face, and put all your cloths in the hamper and wash them, the itch and rash is an added bonus no charge.. lol, it's amazing how many people over the years have said can you please coat these, I'm so tired of that header wrap..stuff..

 

Haha, that's so true...that wrap is a pita. I just wanted to make the point that while it has its drawbacks, thermal wrap is not sinister and as you agree it does offer benefit. I also prefer ceramic coating, actually, for the reasons you discussed. And of course there is no need to touch a turbine housing...the point being that a blanket barrier works extremely well, better than ceramic coating regarding heat barrier properties. The less heat that escapes the turbine housing the more energy it has to spool. You don't want the turbine to cool off. So why does the blanket work better? It is the space within the barrier that prevents heat exchange...there is no space in ceramic coating. Look at satellites, space shuttle and station parts, etc. There are gold thermal blankets around the heat sensitive stuff. The booster nozzles...those probably have barrier coatings as blankets would not physically work. Coatings can handle intense heat and offer protection of the coated material, but they do not offer the insulation properties that wrap does.

Also regarding ceramic coating, I have seen it flake off (usually in high temperature areas like downpipes with 90 degree bends directly after the turbine outlet). I would never coat the inside of a header pre-turbo unless it was getting inspected on a regular basis. Ceramic-aluminum flakes can't be friendly to 18,000 rpm turbine blades.

So given a choice, in general I would choose header wrap over bare, and ceramic coating over header wrap. But with our short run headers I have not bothered with either. Maybe I will send you a pair of headers to try it. What is your turnaround time?

 

Roadsterdoc, For you, I will process them the day they come in, and get them out asap back to TX. and I will agree to "no ceramic inside" on the turbo application just incase. some guys say just do it, even after I warn them. mostly the import guys. I'll I/m you all my info and thank you...regards Bill.