I had header wrap on the pipes of my '01 Ultra.
When I went to True Duals, the heat on the left side became unbearable. It started to toast the side cover. So I called Holley/Hooker and asked them about using heat wrap. They said like all header makers, doing so will void the warranty. It destroys the pipes from the inside out. They also said not to put it closer than 12" from the exhaust port. I went ahead and used it anyway, and it did help cut down the heat. I ran it for about 5,000 miles, and then pulled the exhaust when I had heads and cams done. When I unwrapped the pipes to send to JetHot, I could see that the wrapped area was colored differently than the unwrapped portion. Perhaps it was metal degredation, I don't know. I had the pipes coated and have not used the wrapping since.
I think the folks at Holley/Hooker are being truthful about damage potential. Header wrap is great for a drag and race engine that gets torn down and built up after so many runs. But it may not be good for a long distance touring bike. It does what it is supposed to, retain heat inside the pipe so the expanding gasses have more of a scavenger effect, and help keep temps down inside the cars engine compartment. However the risk of damage is not worth it to me.
My experience is that header wrap does work and cut down on heat. However long term usage could be bad for the pipes. Also, when the wrapping gets wet from washing or rain, it steams and smells untill it drys off.
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Topic: Exhaust wrap (Read 5702 times)