JEFF TIPTON
Senior Member
Based on the engines I have run on the dynamometer I would expect the pounds of fuel per horsepower hour to go up as manifold pressure goes down at the same RPM.
Vance I am perhaps perplexed. I would expect if the vacuum pressure is increasing you would have a higher fuel burn.
With manifold pressure, I am used to seeing a low number like 15 at idle power settings and at fuel throttle numbers like 27 or 28; roughly atmospheric pressure. This assumes no turbocharger or supercharger, etc.