Adding a Whipple, what prop to try???
 

I have a 30' Superboat Y2K. Currently has 600 hp, bravo xr drive, left hand rotation. Spins a 28 4 blade bravo 1 @ 5300 rpm @ 81 mph. I tried a 30 bravo 1 and got 5100 rpm @ 77.5 mph. I've also tried a hydro px-5 26p and got 5500 rpm @ 74 mph.The hull is stepped, X-dim is 1.5" higher than the factory, that's all I know. Dry weight is approx 4500 lbs.

Dustin @ Whipple estimates 800 hp. Any thoughts as to what props to try??

Thanks

Re: Adding a Whipple, what prop to try???
 

You should need to add about 4" of pitch. You may want to try a 5 blade and lower that slip percentage. It's pretty high right now.

Re: Adding a Whipple, what prop to try???
 

What is your wet weight?

What RPM is the peak HP produced?

Julie

Re: Adding a Whipple, what prop to try???
 

Dry is 4500 + 100 gal fuel tank, light gear, passengers max @ 500-600 lbs.

Peak hp is @ 5700 rpm

Thanks

Re: Adding a Whipple, what prop to try???
 

Well, I would anticipate, from youyr initial post that you will run about 91-93 MPH with the new power. So that being said you will need to run a 30P propeller to achieve this speed. I wuold baseline the propellers you have and post results or feel free to call me with them. Safe Testing.

Julie

Re: Adding a Whipple, what prop to try???
 

Adding 200 hp is worth a addition of a couple inches of pitch or 400 rpm. You were were able to turn the 28 at 5300 which means it will be a perfect prop to test with.

Re: Adding a Whipple, what prop to try???
 

Thanks for the help! I was thinking I would be close with the 30p.