The header will expand of course, but the wrap, more or less, forces the heat out instead of holding it at the header. This also increases the scavanging effect on the engines exhaust. I do agree that if you had some cheap aftermarket header, you may decrease the life somewhat, but those type headers dont last worth a crap anyway. Nascar will retire items such as headers quickly because theyre considered a high wear item. I have quite a few friends that work for several teams and they said they dont change headers after every race, just when needed and one team said that they change them at set times on a schedule. If you had that kind of money, wouldnt you, lol. The main thing is if a header wrap is done correctly, it works very well and causes no damage to the header. Some people say that everytime you start the car cold that it holds moisture on the header, think about that.........that header is almost instantly hot, way beyond where any kind of water could possibly be. You have more water farther back in the exhaust where you see that condensation vapor coming from. Its not at the header. Thats one reason car mfg's have drain holes along the exhaust system. Some people would think that their exhaust has a rust hole mistaking that when its just a drain that the car already had.
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Oct 2005 Ride of the month.
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