I would be interested to see any evidence of this.
There are two mechanisms that I know of that could lead to this type of degradation; Increase in temperature may increase the rate that any degradation will occur, and; Chloride stress corrosion cracking; assuming the headers are Austenitic (304, 316 and various others) then chloride ions (salt) held in the fibres of the wrap may attack the metal particularly if there is residual stress from forming or welding the material.
yes don't wrap. Plenty of detailed evidence of failures directly related to wrapped header pipes. Usually its done for cosmetic reasons rather than reducing under bonnet temperatures (pointless on a M3W!)or for performance gains.
If you don't like blued pipes then ceramic coating is the way to go.
It could be worth checking with the factory which wrap they use for the Aus models.
I think that I saw on a photo of the Australian model that the wrap was white. That would infer fiberglass. The stone wraps, made out of rock wool, are steel grey. I've used both. The rock wool line degraded quickly and fell off in chunks. The fiberglass held up longer but had heat discoloration. White is prone to that. Pick a darker color. Much cheaper as well.
What's your mileage? Who cares. Is it practical? See #1. What happens when it rains? You get wet.
quote from laurens: "Not sure if it's a good idea. I can remember that i saw a post of Swissghost that he got an broken pipes near the cylinder head. Could be caused by the wrapping ??"
laurens: take a closer look at the crack in my exhaust! this crack has nothing to do with wrapping. as a trained welder and metalworker, i tell you this is a material error! the pipes are way to thin for all the vibrations and the stress due to differences in heat and cold. if metal is stressed with different temperatures on the same piece, it begins to work against itself. that's physics. so, making sure (with wrapping) the temperature stays the same for the hole header (from cylinder exit to the cats), you release the stress on the steel. the wrap is made of ceramic and its very light. so no arguing cause of weight. this is not a normal stress caused crack. not at all. that crack would look very different. one other reason: material of the pipes and material of the header-piece (last 4cm) is not the same! also different ways of production of those two pieces. so, making sure the engine breathes out very fast, means the exhaust-temperature has to stay very hot, and the hot exhaust fumes run the cats well, you have to wrap the headers!!! period! my brother in law worked for a company producing exhaust systems and diesel particulate filter, they all agree with those facts! wraping the headers for the looks is one thing. but to do it for the reasons i do it, is a completly different story. by the way: mmc and all the engine and exhaust manufatures all agreed with me when they saw the pic of the crack and heard on the specifics of our engine and exhaust configuration.
Looks like DEI titanium exhaust wrap to me. You can get that on Amazon for about $40 for a 50'x2" roll. Not sure if they're running the same stuff across the pond but it looks about the same color, at least in that shot.
