ZugyNA - I'm talking a temp reading on the wrap itself. I've only ever taken temp readings on the part of the exhaust that I wrapped as it's the lowest point on the front of my car and would potentially come into contact with the coroplast belly pan when I install it.
I'm a bit surprised at the temp delta as I thought this product was supposed to reduce temps. I'll leave it on for this tank - unless I get a subtantial FE gain I'll remove it and think of another option for protecting the belly pan.
JanGeo - on my civic, the cat is mounted directly on the exhaust manifold, and the portion of exhaust tubing that I wrapped is aft of the cat; so I'm not exactly sure if this wrap job has any effect on the cat/02
Hummm sounds like it is allowing the pipe to get really hot and retains the heat better - it may actually reduce heat in the area but not when you stop - sort of a delayed heating cooling effect. If anything you should have a nice clean rust free pipe and a quick heating cat - maybe too hot if it doesn't get cooled enough. Carbon Fiber that I have I heated with a butane torch 2000 degrees and when it cooled off it was unaffected by the glowing red heating cooling.
I assume you are useing an infared thermetor? would it be "seeing" thru the fabric wrap, and telling you the temp of the metel under it? I know that to get an acurite reading on some things you need something like a spot of flat black paint, or wrap it with electrical tape, personaly I would check it with my hand, you should be able to tell the difference of 100F with your hand, if/when I doan exaust wrap I would be temped to wrap the fabric insulation with something to reflect radiant heat, like aluminum foil with the shinny side facing the heat source.