Re: Trim tab manual settings?
Fixed Trim Tabs are a little problematic, primarily because if they are angled down too far to help with getting on plane faster they will likely generate too much lift at higher speeds. This can cause handling issues such as bow steering, particularly if there is no power trim on the motor to counteract the unwanted stern lift. And even if you use power trim to bring the bow back up a bit you now have two counter acting forces that will generate a fair amount of drag.
Yes, adding the fixed Tabs at 90 degrees will add running surface aft and thus increase the lift there. Additionally as the bow rises while getting on plane the Trim Tabs will in effect be angled down due to the boat's attitude. This is sort of like lowering them a few degrees and also increase the lift they produce.
For these reasons I would suggest starting with them flush and parallel with the boat's hull surface. You can use a three foot straightedge to accomplish this. Then after you run the boat you could experiment with deflecting them in small increments while watching for any undesirable handling characteristics at higher speeds.
Of course remotely adjustable Trim Tabs offer the best control over all speed, water conditions and weight distribution.
A less expensive and easier to install option than remotely adjustable Trim Tabs, and a big step above fixed Trim Tabs, would be Smart Tabs or Bennett SLT Self Leveling Trim Tabs.
This type of Trim Tab will retract as water pressure increases under them as the boat goes faster, mitigating the problem of too much lift at higher speeds.
