Performance, how's yours?

[LandVF36]

I installed a Lawrance GPS system a few seasons back. One of the features was that it is NMEA-2000 compatible system and they have fuel flow sensors that were only about $70 ea to add. The GPS is great (that cost over $700) but the fuel flow, well you get what you pay for. The had to be mounted EXAXTLY verticle to work and in the middle of last season, they quit. Lawrence technical support gave me the run-around throug 4 o 5 phone calls then I just gave up.

Before they went bad, I got these readings

RPM /MPG /MPH /Port GPH /Starb GPH /Total GPH
750 /1.63 /4.74 /1.3 /1.6 /2.9
1000 /1.69 /5.75 /1.4 /2 /3.4
1250 /1.44 /7.78 /2.6 /2.8 /5.4
1500 /1.36 /8.7 /3.4 /3 /6.4
1750 /1.18 /10 /4.9 /3.6 /8.5
2000 /1.13 /10.8 /5.1 /4.5 /9.6
2250 /0.95 /11.3 /6.9 /5 /11.9
2500 /0.74 /12.8 /9.2 /8 /17.2
2750 /0.88 /17.6 /10 /10 /20
3000 /0.74 /21.3 /16 /12.9 /28.9
3250 /0.75 /26.5 /18.5 /17 /35.5
3500 /0.75 /30 /18.6 /21.4 /40

The boat is a 73 F3 with a pair of GM 454s carburated, pushing 1.82:1 transmissions and a pair of 3 balde 20x22s (? at least that is what they are stamped). I have another set of 4 blade 20x20s that I have not tried but would like to know if I can get closer to WOT and just a little more speed at same consumption and lower RPMs.

That said, I can only afford to poke around a idle anymore...