Efficiency? Getting the most bang for the buck.

[180shabah]

Re: Efficiency? Getting the most bang for the buck.

Given a 5.7 is easily capable of the 250 target HP would I not want to go as high of a ratio on the Alpha drive as possible? What the highest ratio and how painful is that to accomplish?

5.7L uses a 1.5:1 ratio. If your current drive is still in good condition, then you can sell it and replace it(or just the upper if you have a Gen I alpha) with a new drive from SEI.

 

[180shabah]

Re: Efficiency? Getting the most bang for the buck.

Less gal/hr but is it more mpg? I suspect not. And planing hulls tend to wander L&R constantly at idle, very tiring also.

I just pulled fuel/speed data for 5 diferent boats 1 BR, 1 Deckboat, 1 W/A, 1 I/B Ski Boat, 1 jetboat, 1 O/B, 2 I/O's fairly diverse group. There are many, many more, there are also many that do get better MPG on plane than off, they are the minority(except in jet drives where this is common).

I do have to agree that v-hulls at displacement speed do tend to wander, and it is obnoxious and tiring, but unless you spend more time with your intended heading over shoulder instead of over your bow, most boats will still be most efficient at displacement speeds.

4winns 180 BR w/ 3.0GL @800RPM achieves 3.5MPH burning 0.4GPH for 8.63MPG
Same boat at a cruising speed of 28.6MPH(3500 RPM) burns 5.7GPH for 5.06MPG

BAJA 192 w/ 5.0 A1(carbed) @650RPM achieves 3.7MPH burning 0.4GPH for 9.25MPG
Same boat at a cruising speed of 42MPH(4000 RPM) burns 9.9GPH for 4.26MPG

Tige` 22i w/ 5.7 IB(340hp EFI) @600RPM achieves 4.2MPH burning 0.7GPH for 5.93MPG
Same boat at a cruising sped of 22.9MPH(2500RPM) burns 5.2GPH for 4.44MPG

Sea-Doo Challenger 230 w/ twin 215hp ROTAX(jet drives) @2500RPM achieves 6.1MPH burning 1.8GPH for 3.39MPG
Same boat at a cruising speed of 21.8MPH(5000RPM) burns 7.4GPH for 2.94MPG

Boston Whaler 235 W/A w/ 250hp Verado @ 600RPM achieves 3.0MPH burning 0.5GPH for 6.0MPH
Same boat at a cruising speed of 21.4MPH(3500RPM) burns 8.1GPH for 2.66MPG


All number pulled from BoatTEST.com