Re: Evinrude e-tec or Yamaha 4 Stroke
Forktail wrote on Nov 25:<br />Even under perfect conditions (impossible) with zero prop slip (impossible), there is no physical way an outboard running 5500 RPM with a 2:1 gear ratio and a 15 pitch prop can do 39.7 mph.<br /><br />Forktail wrote on Dec 7:<br />So let me see you say it seahorse..."The data doesn't jive"<br />----------------------------------------<br /><br />Forktail,<br /><br />Ever since you posted your calculations, I agreed with you that the figures didn't jive, and said so in three different posts.<br /><br />seahorse: Nov 25<br />Your calculations are correct, but if that was a 17" prop, the speed would be right in the ballpark taking into account average slippage. Perhaps it was typo.<br /><br />seahorse: Nov.25<br />All in all, the proof is on the water, but this may shed some light as to why theory and reality are sometimes a ways apart (concerning props, that is).<br /><br />seahorse: Dec 6<br />I always agreed with Forktail that the one performance test did not compute using a 15" prop. I assumed that it was a misprint that traveled "up the line" somewhere.<br /><br />Forktail,<br />Since you are having a problem contacting Bombardier, what number did you call and who did you talk to? The main number is 847-689-6200 and customer service is 847-689-7090. The individual I contacted is in a position to check out the performance specs and will get back to me. I will share what he or she says with the board
Forktail wrote on Nov 25:<br />Even under perfect conditions (impossible) with zero prop slip (impossible), there is no physical way an outboard running 5500 RPM with a 2:1 gear ratio and a 15 pitch prop can do 39.7 mph.<br /><br />Forktail wrote on Dec 7:<br />So let me see you say it seahorse..."The data doesn't jive"<br />----------------------------------------<br /><br />Forktail,<br /><br />Ever since you posted your calculations, I agreed with you that the figures didn't jive, and said so in three different posts.<br /><br />seahorse: Nov 25<br />Your calculations are correct, but if that was a 17" prop, the speed would be right in the ballpark taking into account average slippage. Perhaps it was typo.<br /><br />seahorse: Nov.25<br />All in all, the proof is on the water, but this may shed some light as to why theory and reality are sometimes a ways apart (concerning props, that is).<br /><br />seahorse: Dec 6<br />I always agreed with Forktail that the one performance test did not compute using a 15" prop. I assumed that it was a misprint that traveled "up the line" somewhere.<br /><br />Forktail,<br />Since you are having a problem contacting Bombardier, what number did you call and who did you talk to? The main number is 847-689-6200 and customer service is 847-689-7090. The individual I contacted is in a position to check out the performance specs and will get back to me. I will share what he or she says with the board