Originally Posted by vroomapunk
Moisture can still be an issue, if it cant excape, it also has to do with other gasses/minerals or something that lead to pitting.
Welds would crack because they are the weakest link i assume, and when you wrap, its everything before and after the wrap that gets the hottest (i.e. the welds at the primaries, and the collector area), so that could lead to extra wear on those areas.
Never heard of a steering rod going bad, its just that, a rod, ive heard of headers in certain cars putting off too much heat and having a starter go out, but still, not often, and not on our cars that I can say.
The truth is, at operating temps, and when racing, the headers are going to get just as hot with coating or no coating, and possibly even with wrapping. Its the faster cooling that people like about the coating.
Coating allows the heat to dissapate and move on faster, which helps the headers cool off faster, and gets the heat away from the engine, definitely better than wrap.
A wrap may keep the ambient temps slightly lower, but coating seems to be the safer and longer lasting bet, especially when you think about coating covering the flange, welds, collector, etc. (not just the tubes like wrapping)
Coating used to be mandatory with mild steel headers, but most of the ones that are made for 5th gens are stainless, and dont require a coating to resist rust, so for most people the extra 400$ isnt worth it for just the faster cooling down of a stainless header.
Sorry Doc for build thread jacking.