bouncedcheque

I'm running a 34 B1 prop on my 27, with 1100hp. I can't get on plane with a 36p, and a few have told me to get a labbed maximus, either 34 or 35 pitch. I've located some, but have no idea if I should grabbing a 15, 151/4 or 155/8 diameter. Must make some difference, me be thinking? Anyone running one?

Tinkerer

What is your prop shaft height and what drive are you running?

bouncedcheque

Don't know exactly, but pretty sure at least 2 inches below the pad. Drive is a modified XR with a standard Bravo lower.

J.P.

What gear ratio?

bouncedcheque

1.5

J.P.

If cavitation is the problem some have said you need to go to 1:35 gears.

Tinkerer

On a Daytona you measure off of the lowest point of the steps.
My prop shaft is 1/2 inch below the bottom and I am running a -2 shorty. I am building a -3 inch shorty.
When You say that you can't get on plane is the prop breaking loose or is the boat just dragging and the RPM's won't come up?
If the prop is blowing out then the Maximus should help. I tend to believe it is the other in that you can't get the engine rpm up. If that is the case then I think your drive is too deep AND it needs a little ventilation to break the prop loose a little.

bouncedcheque

It's is cavitation that is the problem - the boat pops up onto plane right away, it's just that when I ease the throttle forward the prop breaks loose and the rpm rev up. The 34 B1 prop has no problem, just the 36. I know 1.35 gears would allow me to prop down, but would that change anything else? Thanks guys

J.P.

I was told that the increase in propeller RPM with the 1:35 is the advantage on take off. With big cubes (torque) and 1100 hp I would think a 1:35 and a 32B1 would put you where you want to be, depending on drive height.