> I keep meaning to replace my gas heater exhaust pipe, just using the appro-
> priate L of exhaust pipe from the FLAPS.  I don't expect a big difference 

I had never seen the heater exhaust pipe until I scored one at a local yard
a few weeks ago.  The surprising thing about it is the "cap" that sits about an
inch from the pipe outlet.  It's purpose (it appears to me) is to create a
venturi effect when you're going down the road, increasing the flow of hot air
through the heater when in motion.  I certainly had no indication that this was
so from the stub of rusted iron left on the end of the exhaust, but I'm looking
forward to trying it out on a really cold night to see if it helps at all.

This is from an Eberspacher BA6, btw.

Jack
jackr@starfleet.scs.ag.gov