How much hp do you lose through a barvo one? If your motor was 500hp at crank what would it put out at prop?

The Merc HP500 is 500hp at the crank and 470hp at the prop

See here:
http://www.offshoreonly.com/forums/1990314-post82.html

and the link to the entire thread: http://www.offshoreonly.com/forums/g...-1x-drive.html

Ok my next question is 450hp at prop . boat is a 923 Taylor witch is 23 feet long barvo one 1.5 3000 lb dry what prop should I run? It has a 27 mirage on it. I bought the boat with blowed up motor. So I have never ran it. Is the 27 to much or is that a good place to start?

Well the motor is around 500 hp at crank. So 10% would put it around 450

At what rpm's are you making power? Unless your gear ratio is 1.65 or you're planning on spinning the motor less than 5000 rpm's with a 1.5 ratio, you'll need to run atleast 74-75 mph, for a 27" to work. Even more if you're @ 5300-5500 rpm's+. But if you got a 27", bolt it on, it's the easiest way to know.
Another thing. Most motors from merc ect. today are rated SAE crank hp, so don't worry too much about prop hp.

At 5300 to 5500 bob m said it should make 480 to 500 hp
It's a 1.5 gear

A.O. Do you think this set up will run 70 to75? The guy I bought the boat from said it would run 75. But I thought that was bs

480-500 in a boat that size and weight running between 73-76 mph is not impossible at all. But if you must spin at 5300-5500 hp you'll need a 25". Even with a 14% slip you'll run 75 at 5500 hp. I would try the Mirage+ and the Revolution4. No matter what you do, try the prop you have. That will give you a baseline number, but the 27 is prolly too tall though.

Thanks A.O.