Estimation of speed ?

[Louis.]

Anyone willing to take an estimation of how fast a Donzi 28 ZX with 500hp (twin screw mercruiser 5.7l v8's)

Is 70 -75 knts about right ?

[biglepton]

No chance, a Donzi 28 ZX equipped with two 350 (300hp) motors topped out at 71.6mph so with 80hp less, you should expect around 60mph-ish on a good day, flat calm with a clean bottom.

http://www.powerboatmagazine.com/2000tests/apr3.ph...

[Louis.]

Cheers for that. A Great site too !