How good are paddel wheel speedos

[f_inscreenname]

Have a Teleflex paddel wheel speedometer. Brand new install a couple of weeks ago. Sending unit in the right place,wired properly. No curent on the bay. Checked both ways. They say its calcalibrated at the factory (not realy sure where I could find a measured mile to verify,I will keep looking). My question is when I try to figure out the prop slip percentage it says I cant be going that fast? It sure seems I am going that fast (give or take a couple of miles). I have had many boats with many of speedos and I seem to judge them well.

 

[Kenny Bush]

Re: How good are paddel wheel speedos

I have checked the paddle wheels on my boats against my GPS and they were on the money. My paddle wheels are all run through the fishing graphs/sounders. I follow the directions for mounting and everything seems to be working perfectly. If you are in currents, your readings will be off. I think they are more accurate than the peeto tubes..........

 

[Hooty]

Re: How good are paddel wheel speedos

Yo f_in',<br />The paddlewheel pick-ups are suppose to be deadnuts on (except for current). I don't know what formula you're using to compute speed with so try this one.<br />Prop pitch x rpm divided by l/u ratio divided by 1056.<br />This gives theoretical speed without prop slip.<br />Keep us posted.<br /><br />c/6<br /><br />Hooty

 

[DJ]

Re: How good are paddel wheel speedos

F'n,<br /><br />MUCHO better than pitot's. Current will foul you up. Check against a GPS.

 

[f_inscreenname]

Re: How good are paddel wheel speedos

Still only come out with 51 mph. My speedo says 65 mph. Maby I am doing something wrong. Its a 1972 Volvo 270 outdrive (should be 1.68 ratio,could be a custom ratio.I have found that nothing on this boat is stock) 19 pitch prop with some cup. Motor is a 360 Chrysler around 310 hp turning 4800 rpm (a little high,I plan on bumping up to a 21 pitch). <br />Like I said befor,I have had experence with many boats befor, Sure seems like I am doing around 65 not 51 mph. 51 mph was my last boat with a diffrent type of speedometer.