Reply With QuoteTry this calculator. Again, it's an estimate, but this one takes into account hull length and weight.
http://www.boatpropellers.com/
Mine hits about 5000-5100 rpm. My lab job cost me about $300. I took him a stock 26P and he took out some cup and pitched the prop up one pitch to make it almost a 27P. My boat ran 79 when it was me and a buddy with no gear and about 10-15 gallons of fuel I am guessing.
The prop calcs are pretty good estimates for how fast you should be going, but they dont take into consideration the hull type, weight, x dimension etc. So, like I said, it is an estimate.
Try this calculator. Again, it's an estimate, but this one takes into account hull length and weight.
http://www.boatpropellers.com/
Do you have a Smartcraft gauge on your HO? My Livorsi tach reads 300RPM higher than the Smartcraft at WOT. I'm not sure which one is correct, but the rev limiter is tied to the the computer/Smartcraft. When I was figuring out prop slip, best prop, etc. I used the Smartcraft, my GPS speedo and a handheld GPS to dial it all in. If you don't have a Smartcraft, a lot of shops have a hand held gauge that plugs into the cannon plug on the top of the engine. IMHO it is the best way to get an accurate reading on RPM vs. speed.
No. I am running Faria Guages. I was thinking about a GPS speedo..but the guage. $140 + the receiver $200. For that price I was considering getting just a handheld with maps for the same price.
You must mean 4%
Nevermind me. It is the angle of attack that is 40. I was reading and started computing stuff and it seemed to work. I was all happy to figure it out and now I realize I'm a dumba$$.
No. I am running Faria Guages. I was thinking about a GPS speedo...Handheld GPSs work great. Mine and the one in the dash are always in agreement. Any MAG or MAG/HO (or Blue motor) can be purchased with the big expensive Smartcraft display or a small, much more economical digital gauge. It tells you water temp, water psi, oil psi, oil temp, RPM, gallons/hr, trouble codes, etc., etc. You may think about adding it at some point. It's obviously not as easy to see as a dial gauge, but is a valuable tuning tool.
A Smartcraft 1000 looks like this:
http://www.***boat.com/image_center/...2442SC1000.gif
Try this calculator. Again, it's an estimate, but this one takes into account hull length and weight.
http://www.boatpropellers.com/
The weight and length does not effect that calculator. I tried different weights and length and it still gave me the same speed? Must be a gimmick to make you think it is different than the rest.
The weight and length does not effect that calculator. I tried different weights and length and it still gave me the same speed? Must be a gimmick to make you think it is different than the rest.
You are exactly right. Prop calculator neglect the weight and type of hull. Those two things just so happen to be some of the most important factors. Prop calcs suck in general.
You are exactly right. Prop calculator neglect the weight and type of hull. Those two things just so happen to be some of the most important factors. Prop calcs suck in general.
But if you are going faster than your theoretical speed, you know you have a problem.
But if you are going faster than your theoretical speed, you know you have a problem.
On GPS, I have done 79.8 mph with a 27P Bravo labbed.
I have many problems, my prop is just one of them.
On GPS, I have done 79.8 mph with a 27P Bravo labbed.
I have many problems, my prop is just one of them.
Were you throwing the GPS towards the front of the boat when you got these #'s.
Posting Permissions