How do I know my setup is dialed in?

[gregstukey]

In other words, how do I know that, if I'm going for max possible top-end speed, that I'm receiving the most out of my set-up (prop choice, etc.) to my WOT range (4000-4400) for my 92' 5.0 Cobra V8 Ford in a 20' Sunbird?

The boat's top end speed caps at around 42 mph (depending on how glassy the lake is) at around 4100 rpms (aluminum prop 14.5 x 19...i think--forgive me for not knowing for sure).

 

[QC]

Re: How do I know my setup is dialed in?

Well to absolutely "know" you have to insure that everything is at it's best. The engine must be performing up to it's full potential which means all of the pieces, fuel, ignition, compression etc. all need to be right. Then you need to be sure your hull is as good as it can be, no growth, straight, no unneeded weight on board, no waterlogged stuff, etc., and of course your drive needs to be right too. If all of that is right, then you can dial in the prop stuff . . . Right off the bat, if your goal is top speed, you need to go with a Stainless Steel prop . . . for top speed probably a 3 blade. When you are ready with the other stuff, repost this in the prop forum and there are some great heads over there to get this right.

Oh, with your existing rig are you trimming properly? Will she porpoise (rhythmic bouncing of the bow) as is with the trim all of the way out? If you can't make her porpoise as is, then you need to shift some weight aft, if you cannot trim up because she violently porpoises as is, then you need to move some weight forward . . . they are usually fastest just at the point that they begin to porpoise.