| The exhaust manifolds are about 500 degrees hotter than the DP's. Someone should just tape a thermometer to the underside of the hood and do some before and after measurements. The physics involved get extremely complex, and the fine points are over my head. The problem is, most peeps making the recommendations haven't got a clue either. There is a theory that you want more heat radiating off the pipes (the "don't wrap" school) for a larger temp gradient which would lead to a larger pressure difference and improve flow that way. That is because the turbo-charger's turbine is driven by the DIFFERENCE in pressure between the exhaust manifold and down-pipe. Then there is the flow dynamics of hot gasses versus not as hot gasses that suggests the hotter that gas, the better the flow. Those folks want to keep the temp trapped in the DP's. Some folks wrap DP's because they want to minimize underhood temps. But as above, unless you're addressing the much hotter exhaust manifold, then I don't feel wrapping your DP's will make a measurable difference. Maybe someone can prove otherwise with a thermometer and some "before and after" wrapping measurements, but I'm not aware of any such data. Nor am I aware of any dyno measurements that show a difference. The last issue in my mind was longevity of the pipes themselves. Some folks feel wrapping helps this. But then there are others who say that "trapping" whatever moisture may or may not form when the pipes cool with wrap might not be such a good idea. For every pro, there is just as good of a con on this issue, IMHO. I thought about it a lot when I got my DP's, and decided to go with an aftermarket coating (Jet Hot Sterling) mainly for the lifetime warranty on the durability of the pipes.
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