I am planning to run a rear exhaust engine mounted upright such that the exhaust pipe will penetrate the firewall, run inside the fuselage for approximately 10 inches and then make a 45 degree bend and exit the bottom. The pipe will be 7/8 inch diameter. This is not a tuned pipe.

What is the best method of insulating the pipe? I have thought of automobile header tape but that seems heavy. What material is best, at the least cost, for this type of insulation and where do I get the material.