during his flight with Dave Leonard, he personally observed 45 gallons per hour fuel return with one of Tracy's pumps on and 80 gallons per hour with both pumps on!!  Dave has a flow meter on his return line.   

That may be what the meter is reading, but (I believe) not representative.  I don’t have the data handy, but I once pulled up some specs on the pump (or equivalent) that I got from Tracy, and I think about 30 gph was max, and maybe less at 40psi.  One reason for exceptional high readings from a Floscan type meter downstream from a pressure regulator is there are almost always bubbles in the fuel as some low vapor pressure fractionates flash due to the sudden pressure drop, especially if there has been some heating as the fuel traversed the fuel rails.

Al

Wow, is that true Dave?  That seems high, but I have no way of measuring it.  I run both pumps all the time (aside from testing them individually during preflight), so I guess my fuel stays pretty well stirred :-)

Rusty (yes I know you don't need to run both all the time)