Why should we do this?
you can ceramic coat or wrap ti tooI'd do this but i got the TI headers and pipe.
i actually like the look of the wraps
making the gas hotter expels the gases faster. the idea behind ceram and wrap is to expel the gases quicker not protect the header or parts except on a twin rear header where it burn the shock and makes it fade IMOI believe that the wraps are good to protect various 'items' from heat, but not to hold the heat in the header. For example: you can use the wrapping for the protection of fuel and oil lines, wiring, covering a starter motor, etc.
Cool air needs to be around the header, and insulating it with a wrap to hold exhaust heat in makes the header material temperatures near molten. When you wrap the header you trap the heat in the header, but also in the material that needs to breathe to dissipate heat for it's own survival.
But, when the header is not allowed to cool so as to dissipate those extreme temperatures that the wrap is controlling, you have now developed a heat absorption that compares to thermal friction. This causes temperatures to continue to rise beyond the normal exhaust gas temperatures (EGT's) the header material was designed to withstand. This holds true as with most any insulation.
The EGTs stay the same but the properties of the header material changes by amplifying the temperature due to the insulation.