Just wondering about ...
... how an aerosol might reduce the heat and
... cat works best on higher temps, if you apply the aerosol it might reduce the cat temp which means lower cat efficiency?
In theory it should help both with the blueing and provide better performance. Sort of like exhaust wrap done inside-out.
Possible downsides: reducing the inside diameter of the pipes reduces flow (probably negligible with a spray), and clogging the CAT and/or muffler if any peels off (this would be my #1 concern).
Prepping the pipes will be the key to success. I saw they have instructions on how to apply the product to used pipes; I'd follow them even with a brand new set to make sure you get the best possible adhesion.
I called Eastwood today and spoke with thier technical department. They assured me it wouldn't peel and that it would have no adverse effect on the chrome.
I ordered two cans and am going to try it out on a scrap pipe I have laying aroung before I hit the headers. I'll let everyone know how it does.