Hi - I am wondering if an anticipated speed can be computed based on some boat characteristics. The boat is 19.5ft (monza). I am running a VP C-7 duoprop which I believe is a 27-28P prop. I have a 550 hp/torque engine that peaks out around 5500 RPM. I do not know the gearing in the outdrive (the tag is worn off) but I can tell you it is a 290 drive.

The boat is being painted and the duoprop is getting installed. I should have the boat back in a couple weeks, but I am curious where this may end up. I do know that with a VP 280 drive with 23P a left rotation prop the boat would only go about 53mph, any chance the change in outdrive and prop might take me to the low 70's?

Thanks!

- scott -

Generally Duo prop helps eliminate slip but cause massive drag. I know the Blackhawks were very nice though, but Merc abandon those years ago.
My unscientific and factless observation of most VP Duoprops is that max out in the low 60's, even with stout power.
I would think a boat change or outdrive change would be required to get to the numbers you're looking for. JMHO.