Quote:
Originally Posted by Woodsy
Dave...
That Bravo 3 Dual prop drive is the key.... it pushes alot of water very efficiently at lower speeds.... nothing pops a boat on plane better or quicker than the Merc Bravo 3 or Volvo Duoprop setup...
But like everything... there is a tradeoff to be made!
The dual props become less efficient at higher speeds... thats alot of blade area to spin and it requires sustantially more HP to spin the faster it goes... and water does not compress. All things being equal thats why the huge difference in gasoline consumption.
A high performance boat such as my 26' Donzi is setup (weighted, balanced, propped) to go fast... 67-69 MPH. But like everything else there is a tradeoff. The boat doesnt like 25 MPH... even with the tabs down! The propeller is cavitating, the stern squatting and the nose is high.. and the wake rivals a Carver! I am sure its compounded on the larger heavier high performance boats.
Its funny but everything settles down smoothly at 30-32 MPH. You wouldnt think 5-6 MPH would make a big difference but it does.
For the record.. I seriously doubt the MP is going to pull you over for going 30 MPH... but you never know.
Woodsy
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I knew it helped, but did not realize it helped that much.
You know a B3 lower gearcase bolts right up to a B1 upper gearcase, right? Might be worth picking one up on eBay while the 45/25 law is in effect and you can't really use the top end of the B1. A 1.5:1 ratio B1 upper gearcase would be a 2:1 ratio with a B3 lower bolted on, if memory serves. The swap takes mere minutes.