My friend and I were talking about the theoretical max speed of his boat the other day using the standard formula that uses rpm, gear ratio, pitch, and prop slip to get the final mph speed. However, I was wondering if two engines and two props change the formula. Here is the boat info:
1) Max Speed
2) Stainless 4 Blade Mercury Bravo I
3) 28" Pitch x 15 1/4" Diameter
4) 5000 rpm
5) Twin 600 HP 502s (~1200 HP total) with Bravo One Drives (1.5:1 ratio)
6) 1989 Chaparral Villain IV, 30', ~6500lbs
Using 10% slip I calculate the max speed to be just under 80 mph. Any chance the boat will go faster? He has yet to GPS the max speed and we both know the speedometer is probably lying.
1) Max Speed
2) Stainless 4 Blade Mercury Bravo I
3) 28" Pitch x 15 1/4" Diameter
4) 5000 rpm
5) Twin 600 HP 502s (~1200 HP total) with Bravo One Drives (1.5:1 ratio)
6) 1989 Chaparral Villain IV, 30', ~6500lbs
Using 10% slip I calculate the max speed to be just under 80 mph. Any chance the boat will go faster? He has yet to GPS the max speed and we both know the speedometer is probably lying.
