The key here is... you draw in "Cooling air" to protect the parts. If Henke set up is pipe properly... And I'm sure he did.... the venturi effect will draw cool air around the engine, and in turn... the foam never "Sees" the hot engine, or exhaust temps.
I have a little crappy T-45 that was meant for an EDF system... but I stuffed in a MW44, and I use a simple single wall pipe. Every event I go it... guys ask.... "Doesn't that get hot?" my answer is always "No, it doesn't." I still get a few guys who don't really believe me, so I start it up, and after 2 or 3 min of idling... the top of the fuse is still cool.
Last edited by Dr Honda; 10-10-2013 at 10:56 AM.