Here's the speed/pitch table for you...

[stevens]

Hi guys,<br /><br />in this other thread ( Link to thread ), there was a picture of an interesting table.<br /><br />It looked so intriguing that I made my own version of it. If you're interested, you can open this link:<br /><br /> Speed-gear-pitch-rpm-table <br /><br />Enter a slip rate, and the tables show your speed at various combinations of gear ratios, rpm, and pitch. It is also possible to enter your own gear ratio. At the bottom of the worksheet, click on the tabs to switch from knots to mph to km/h. <br /><br />For example, if you have a 2.0 gear ratio, a 20" prop, 10% slip and a strong enough engine to pull it at 5500 rpm, your speed would be 46,9 mph.<br /><br />Hope you'll find use for it.

 

[shep70057]

Re: Here's the speed/pitch table for you...

Thanks..... this will be very useful.

 

[Mark42]

Re: Here's the speed/pitch table for you...

That is great, but I can't get the custom ratio to work. My manual lists the ration as 12:29(.41) but when I enter 12:29 it converts it to .52 and I get 500mph. What am I doing wrong?

 

[Silvertip]

Re: Here's the speed/pitch table for you...

Your ratio is not .41. The numbers 12:29 mean the prop turns 12 times when the engine turns 29. That means the ratio is 2.41:1 Most outboards run anywhere from 1.83 to about 2.67 (Evinrude E-tec 40-60 HP). Most larger engines run 2.0 to 2.25 although the high performance engines are back in the 1.85 range.

 

[stevens]

Re: Here's the speed/pitch table for you...

Upinsmoke is probably right.<br /><br />If you enter 2,4167 (with a comma) in the blue custom ratio cell, the table should work, I hope.<br /><br />(29/12=2.4167)<br /><br />Oh, by the way, it is absolutely possible to save a copy of that spreadsheet onto your own hard drive and amend it in any way you want.

 

[Realgun]

Re: Here's the speed/pitch table for you...

I did not download the table thing but the links table is dead on for my boat RPM and Pitch!<br /><br />4500 RPM<br />15 pitch<br />32 mph!!!

 

[Mark42]

Re: Here's the speed/pitch table for you...

It says I should be 29.4 mph. I do 29. I guess my boats not set up right.