Ryan, Richard wrote
>So the real question is: At which rpm (3,200 or 4,000) does the engine
>produce 30 hp most efficiently.
>
>And the answer is: Beats the hell outta me. I don't have any engine
>design info that I can use to get the answer. Some have commented that
>changing axle ratios and/or tire sizes will change the equation. That is
>correct because changes the 2 rpm points and the efficiency will be
>different at those rpm.
Find out empirically. Plot out a flat level run on the interstate of,
say 35 miles out, and 35 miles back. Use a gas station as your base camp.
Fill the tank. Make your first run at 70 mph in 4th gear, 35 mi. out, 35
mi back. Fill the tank at the same pump and record how much fuel it
takes. Make run #2 :35 mi out, 35 mi back, at 70 mph in 5th gear. Fill
up at the same pump and record how much fuel it takes. The run that
takes less fuel is obviously the more efficient. The 4th gear run will
spin the motor 56,000 more times on our 70 mile, 1 hour trip. Hard to
imagine that your foot would be lighter on the gas in 4th than 5th to
maintain 70 mph. I'm guessing you'd do better in 5th, but only
experimentation will tell us for sure.
-marc
==========================================================================
Marc Tyler
Designer,
Animal Firm
830-324-6578
www.animalfirm.com
|