Arneson drives conversion prop calculator
 

I'm wondering if anyone knows an approximate formula to convert same power from Bravo to Arneson in relation to prop size? I've got 4 months to shop for some props so I'm hoping to at least be able to get a few sizes on hand initially. Right now Herring 28 5 blades and a 1.5 ratio spin to about 5750 on my Bravos. I can spin between 5600-6000 with good results so I've got some room. Rik has indicated an increase of 10 mph is likely so taking that into account I was thinking 32 - 34" 5 blades would be in the ball park. I seen a video on youtube of a 32AT with about the same power but he there isn't any notes on what size props he's using. Anyone happen to know?

If i recall Rik told me rake is one of the most important factor, dont bother with anything less the 18 degrees when shopping. Ive not really heard of anyone using Bravo B1 props, cant imagine thats going to be a great choice running on the surface.

Glass Dave's spot on. For my boat I run 18x35x18r 5 blade mercury #6 cleavers- 108 mph. My other set of cleavers are 18x37x18r- 110 mph. I have twin 850hp. If you run anything under 18 inch diameter it is hard to get on plane.

Reach out to Jeff, he's in Grand Rapids.

The benefit of the ASD7 Bravo kit system is the extension boxes. It gets the prop into higher cleaner water, as it lifts from the hull, and it creates more leverage for the prop bow lift.

I think jeff is running 34 Mercs. I know he was talking about 540 NA motors so my guess is maybe a little north of 700 torq but not much. I'm building a pair of engines that will be right about 900-950 torq so I was hoping to get some others to compare...

Original props were 17.5 and I had issues getting on plane. Moving to 18r was a huge difference.