Mario_Marques -
Quote:
Originally Posted by Mario_Marques
Hot gases are less dense and have higher viscosity, density decreases faster than viscosity increases, and one other thing, you have pressure from the engine in the exhaust
You may do this experiment at home with an hair drier and a simple piece of paper 
Please, take a look at this examples:
Convective Heat - Air Velocity and Volume of Air Flow
About the exhaust rust, well have in my motocross bike(not a street bike, my bike is only for racing, not road legal) since 2008, and no rust at all, but i think it's possible, but i read a lot about damage in the exhaust but never seen a real one.
And in my car i already kill a turbo manifold with thermal coat(it brokes in tow pieces!  i I never thought it was so effective ). |
I also heard that too-hot exhaust gases can damage your catalytic converter (but maybe that's only under high-RPM performance scenarios?!?!?!?). For racing I think this doesn't matter, but for passing emission tests it does.
CarloSW2