90HP vs. 150HP

[coresuper]

I have a 24' Sylvan with a 90hp Evinrude ETEC. I am thinking about trading the motor in for a 150 hp ETEC. I get 22-23 mph with the 90hp. What speed do you think I would get with a 150hp?

 

[ahicks]

Etec 150 not that much heavier than the 90, but still, betting you don't gain a bunch. You might crack 30 mph though.

 

[Silvertip]

And burn a lot more fuel in the process.

 

[coresuper]

Gives me a few things to ponder. It's quite a bit of money.

 

[Scott Danforth]

. I get 22-23 mph with the 90hp. What speed do you think I would get with a 150hp?

Im going to guess 25-26mph after you update to the 150. you will burn 50% more fuel

 

[ahicks]

Bucks spent for bang received, going to be hard to justify if your only reason to buy is to go faster.....

 

[dingbat]

Sylvan 22 ft. Pontoon from ETEC performance library

Etec 115 HP = 5620, 30.4 mph, 3.0 mph - 18.4 mph@3.6 mpg

Etec 150 HP = 5200, 42.1 mph, 2.8 mph - 14.5 mph@ 4.4 mpg

 

[ahicks]

dingbat, do you have a link to those tests? I'm curious regarding the hull set up. To get 42mph from a conventional 2 tube 'toon is pretty impressive.

 

[silveraire]

http://org-www.evinrude.com/Content/Pdf/neutral/performanceReports/PE1070.pdf

http://org-www.evinrude.com/Content/Pdf/neutral/performanceReports/PE1063.pdf

Not your exact toon, but will give you a good idea. I find these reports hard to believe, so take it with a grain of salt.

 

[ahicks]

Thanks silveraire.
The boats are very lightly loaded, have 25" tubes and "performance" strakes if I've deciphered the model info correctly. So though I initially found it to be a stretch, it's believable.

The 90hp numbers I was OK with as I had ours out (90hp Honda) prior to installing any furniture on it (likely MUCH lighter than the 90hp Etec test rig), and missing the "performance" strakes, it ran 25-26 on the GPS using the same prop size they're using in the Etec tast. It was the 36mph with the 150 I was struggling with, 10mph faster yet.....