At 08:26 AM 3/25/2012, Chris S. wrote:
>Look up stoichiometric fuel ratio, run it past your RPM
>observations, and you might get a part of your answer.

~14.7 pounds of air to one pound of gasoline, right?  That's what the
ECU maintains when it's running closed-loop (oxygen sensor active),
so the three stages of the catalytic conversion will proceed in
balance, each stage using the products of the previous one.

But I don't understand your point here.  In an ideal case of no
differing pumping losses in the engine (and same scavenging, same
driven load, everything else equal), the mass of air taken in and the
mass of fuel burnt should be the same whether at 3,000 rpm or
5,000.  What am I missing?

Yours,
David