I bought the headers from the GB, and since HPC was too expensive for me exhaust wrap was the way to go, and i advice everyone that did not get the HPC coating to wrap their. Only done one side because i ran out, 6m was JUST enuf, ive wraped them like a pro Im now waiting to receive the other 6m to do the other side aswell. Heres some pics Ohh yeah and cable tiers are only there because i didnt have metal things, will buy some tomorow 2 pipes were individually wrapped all the way up to where they join, the third middle one did as much as i could then went over the top off all three
Yes a mate of mine did it to his s14 nd it helped reduce heat under bonnet, improve hp, different sound aswell, a bit deeper...
its the go yeah header wrap is the go. it should remove alot of the tinny sound that sometimes comes with thin wall steel headers cool
none none that i know of adriano. im sure the scientists could think of something negative involving protons and neutrons
from an engineering pOV i cant see any. One might argue that they will cause cracking with cast manifolds, but these are not cast
I read in an article that nascar changed from heatwrap to coatings. Found that after each race the headers became warped from the heat retention and not usable. Had to renew and became expensive to keep on swapping extractors. Im no engineer and have no validity behind an argument for not using, but i might be doing a bit more research.
maybe yeah maybe, from personal experience i have wrapped at least a dozen 6 cyl and v8's and still working on the same cars years later they have not had a problem.
Nascar races last about 3 to 4 hours, the engine rpm and tempture stays high almost all the time, very different to a street car.
Nice work adriano, A little hint. Don't buy your header exhaust wrap from auto stores you'll pay through the teeth for it. You can buy it at Blackwoods, along with your stainless steel cable ties for about half. Also you buy it in 60m rolls! I think is was $60 a roll when I got it last.
The heat not being able to be expelled from the material causes the materials crystalline structure to be altered, effectively being called "crystallising", this process can lead to a brittle material (it's another form of heat treatment, although taken too far), once a brittle material has been cured, it can lead to cracking.
rapid cooling i think this only happens when the material is rapidly cooled. slow heating and slow cooling will anneal metal?
that's quenshing. annealing is when you heat the material to 40deg or so above it's critical temperature and allow it to cool in a furnace (heat condition), but you can't really call it annealing because of it's cyclic process, also you can call it a number of things, eg tempering.
Bing! Dead on. You will actually remove any residual stresses from the material from manufacture. Your using the turm "slow" a bit losely, some annealing proccesses take days or weeks... You will get a pearlite structure in the steel which is relatively flexible because the iron and carbon gloop together in large chunks What Chr1s is talking about is Tempering. Not exactly likely on an exhaust manifold... You would have to heat it to 1300deg then rapidly cool it in brine or oil. This would give you a nice Martensite structure which is very hard and great for tools. The addition of heat bandages to this will not cause this to happen at all, actually the opposite. The aftermarket manifolds that you always hear of cracking are generally thin 304 stainless which hasn't got the best high temperature properties and are made with little thought as to how they will expand due to the heat. The continous heating and cooling cyles cause continous cyclic stresses and they end up failing due to fatigue. I WILL be wrapping my extractors after I (finally) make them. Might also ceramic coat them as I can get this very cool brushable ceramic from work that is used on the inside of pumps. I will also be putting flex joints on my exhuast too. I'm thinking of making my own again out of 316SS steampipe, mmmm sea-water-proof polished goodness.
