Owner of a Formula 311, and am very underwhelmed with the performance. I have no delusions of 100mph, it is only 454/330's and Bravos, but expected better than 38mph gps from it!

Bottom is fairly straight (1/8" of total hook in the last 6'), props are 23" cleaver looking things, trim helped until it started to porpoise. Hull is not waterlogged. Motors spun up to 5200rpm fairly easily, but topped out there (limited?) Boat ran super wet, and never freed up. Running less than 40gal of fuel.

What am I missing? Where should I be on props?
I was expecting mid 60, and hoping for 70. Doable? What kind of HP do I need?

Many thanks.

You should expect low 60's for top speed. Try some 23 Mirage plus props. Those props have to be completely wrong for the boat.

They like Hydromotive Quad 4 props. I had 600 - 650 HP blower motors in mine and it would nudge 90 in the right conditions. Are you running Bravo or TRS? Have you checked your drive trim and toe angle? Are K planes comming up? If TRS do you have trans slip?

Running Bravos, Trim has been gone over and tested from all the way up to porpoise (and it was faster trimmed up as expected). Drive alignment looks good to the eyeball, but hasn't been taped yet. Planes work correctly and were all the way up for speed runs.

Borrowed a set of 23 Tempests from a friend and will give them a run tomorrow. Mirages are on order.

F311- Were you running 600hp thru Bravos? I've been told they are only good to 500. This car motor thing is all new to me, used to running little tunnel boats and whackers!

330's max around 4400 rpm, I am betting with Bravo they are 365 mags, should spin around 4600 with a standard 23 Mirage and run 62-63 WOT
at 5200 rpm you are WAY past the power point of a 330 or a 365, if you only see 38 you are doing something wrong... big time.