Offshoreonly.com - Too much prop slip? What is too much?

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I would actually test a 2" spacer and go from there.

I have a 1 1/2" spacer on the way. Which lower should I try first? Should the IMCO with the nosecone made on it be faster as a general rule?

Quote:

Originally Posted by snapmorgan (Post 4449098)

Trying to figure out why boat is so slow. Current setup on my 28' Advantage V hull is 700hp(dyno proven) 1.5 ratio XR upper and -1 IMCO lower turning 26" and 28" B! 4 blades. I am seeing around 20-22% prop slip throughout the mid and upper rpm ranges. I have tried a std length lower with no change. I have tried a -2 lower which picked me up a couple mph, but blew the prop out pretty bad getting on plane. I have also tried a 27" Hydromotive 4 blade which I could blow out at will. I can turn the 26 at 5400 rpm and the 28 at 5100 rpm with around the same top speed of 71mph.
Here is where I think the problem is. The bow of this boat is heavy, I just can't get it out of the water. I cannot even trim it up high enough to make it porpoise. Once the boat starts coming out of the water, I can keep trimming up until the prop blows out without really changing the attitude of the boat any. It has always been this way with every different setup I have had on it. Would a 5 blade prop help? If so, what brand and pitch? Is 20% prop slip excessive? Transom has a small notch, but would an extension box or ITS help? I realize that this is not the fastest hull out there, but I think I should be closer to 80 than 70. I keep throwing more power at it with very little improvement in mph.

Thanks in advance for the help

Call me and we can talk or email me

I have the perfect solution to your problem

My name is jj

[email protected]. My email

Phone is 716 366 0922

Call me and I have a solution to your problem

I am glad to help

I have a answer to all your problems

Jj

Quote:

Originally Posted by conneroutlaw (Post 4451682)

Why not just explain the "solution" right here so that we can all learn something?

Quote:

Originally Posted by Bill 3 (Post 4452290)

Why not just explain the "solution" right here so that we can all learn something?

Here is my solution, call my expert and get his unbiased solution, call Doug at spinellie brothers, and tell him the situation and he can tell you the cure.

Jj

Quote:

Originally Posted by SB (Post 4452291)

Creepy

That is creepy, creepy is when you don't have a solution to the problem, and you want to use your boat
That is creepy

Just a quick update. I installed an 1 1/2" spacer and went out testing with my 28P Bravo 1. It picked up a couple mph with the same rpm. Running 75 @ 5200 for about 2 miles when it decided to snap a tooth right off one of the upper gears. I guess it was successful. Sort of.

Quote:

Originally Posted by snapmorgan (Post 4456799)

Sometimes slip is good........