Set Up Question

[Dingie 2]

I have seen a few articles in Bass and Walleye that shows people checking the bottom and transom angles relative to the gearcase angle after a high speed run to help determine whether or not a particular combination is well mated. If you measured the angle that the gear case was in during a WOT run and measured the bottom angle how much more trim should the gear case have if a boat was set up correct. Joe R

[vector mike]

Depends on how much bowlift you want. Different hulls require different amounts.

[Dingie 2]

Victor Mike, I thought that it was faster to use HP to make the boat go forward and not waste HP using excessive trim to lift your boat. I was wondering what a good ballpark figure would be. Example for every 4 degrees trim needed to lift add 1/2 set back. What degree of trim would it be better to add more set back instead of using trim ? Joe R

[vector mike]

What I was trying to say is the propshaft should be level and if you trim it away from the boat all it does is lift the bow. I run a cleaver and it lifts the back of the boat but still lifts the bow a little to get it running flat. I guess there is a point to where you can trim and it doesn't lift the bow anymore but I never go that far with mine. Maybe I'm reading to much into this. If so just disregard what I said. I've had a long day already.

[Dingie 2]

Thanks for trying to help .It isn't you I am not asking this question very clear. Joe R

[vector mike]

Isn't setback usually determined on the amount of weight you are trying to carry in the bow? That would mean that every boat would be different with no one formula for all boats.

[vector mike]

Either I can't get the right point accross or I'm just digging myself farther into a hole. Probably the later of the 2. :eek: Ok, I'll stop now. Hope you find out what you are wanting to know.

[DockBoy]

Dingle, setback is used for two functions:

First , it allows the WEIGHT of the motor to help lift the bow bu adding to the lever length from the longitudinal balance point of the boat.

Second , the additional setback also allows the prop to turn in "clearer" water... allowing a higher initial engine height , thereby making the motor/prop combination work miore efficiently.

The most efficient setup , no matter what kind of boat, is when ,at spped, your output shaft is dead level with the water surface and your hull pad is as near deal level as you can get, but is airborne. THINK about that,, in this way, NO power is wasted trying to lift the boat any more than necessary.

Have fun ,
DockBoy :D

[Rickracer]

If you need more than that to acheive max speed, you need either some weight re-distribution or more setback. How much is highly dependant on the hull, motor type, size, and weight, and your intended use. You may have to "sneak up" on the sweet spot by adding a little bit of setback at a time, or take an edjucated guess and see how it works out. :cool:

[Dingie 2]

Thanks Rickracer that's what I was looking for more than a couple degrees of trim starts wasting power.Output shaft dead level with the water at speed that makes sence dock boy. Thanks Guys Joe R

[hsbob]

that right but hull design is the real factor. both the 20' hydrostreams and allison are about the same weight, but look at the wot angles needed for max speed. the allison is able to reach the 90 mark while the hydrosteams get slightly over 80 with the 200xs. i need lost of bow lift with my voyager to get max speed. the allison is almost flat. look at pyro's picture and compare it to a allison at wot.