Rage

What is the best set up position for trim tabs to insure that there will be no drag at WOT?

HighPriority

It will always depend on water condition, but all the way up is fastest.

Rage

HighPriority,

I should have phrased my question better. I ment to ask when you first install a trim tab system, where should the full up position of the trim tabs be to insure no drag at WOT with the trim position switch at 'full up'?

Wally

Are you asking how to mount them on the transom? or adjust the indicator to read correctly? If mounting then its usually about 1/2 to 3/4" above the bottom of the boat.
If you asking about the indicator......well i usually take a straight edge and place it on the bottom of the boat and extending out the rear under the tab....then adjust the tab till its parallel with the straight edge. At that point i either mark my indicator where its at or adjust it so its in the middle on the line between 4&5

hope that helps....

Rage

Wally,

How to mount them on the transom was what I was after but the indicator info was helpful as well.

What determines 1/2" or 3/4" up from the bottom of the boat? Tab length from the transom to tip? My tab length will be 16" or 19" depending on brand.

Is the full up tab position to be parallel to the boat bottom or some angle above parallel to insure no drag at WOT? Once I drill the holes for the power cylinder transom mounting I do not want to have to move them.

Thanks!

Steve Zuckerman

Rage,
I would position your tabs so they are + 2/4 degrees at full up position. Here's why. Most of our boats run at 2/4 degrees + at WOT, relative to the water surface. In that scenario, your tabs are parallel to the water at full up. Most tabs still have plenty of ram range to give you all the negative trim you need, even when mounted + 2/4 degrees, full up.
BTW, regarding performance, less tab usually equals better performance. Tabs are very useful when you have a lateral imbalance, rough water, or heavy loads during plane off.
Regards,
Steve

Dave M

Here's a few pics of how mine are mounted. In the first pic you can see that they are about 3/4-1" above the hull. In the second pic you can see that they are angled up when in the full up position. I don't think they are touching the water when all the way up.

Wally

the bottom of the boat to the bottom of the plate that mounts on the transom of the boat.......or should i say the lowest part of the assembly thats closest to the transom.....nothing much to do with the tab that extends out from the plate.

Rage

Good information everyone, thanks!

Steve,

The "2/4 degrees +", does that mean 2 degrees to 4 degrees plus range? Just want to get it right.

Steve Zuckerman

Rage,
If you look at Dave's tabs, that's what I am refering too. Fully retracted, or up, they should be several degrees above parallel to your hull. That way when your running with positive trim in smooth water your tabs will only be catching spray off the corners of the transom. If they were installed so that they were parallel to the hull when fully retracted, they would actually be slightly deployed when running with positive trim, which would increase drag and slow you down.
Tabs are a great tool to fine tune your ride, but you'll generally want to use as little tab as possible for the conditions you're running in.
Regards,
Steve