Proper Trim Tab Size???????

tank1949

Lieutenant Commander
Joined
Apr 4, 2013
Messages
1,767
I found out the other day that my trim system is woefully too small. I have hyd. 12x9 tabs on a 29 ft Proline. Bennett recommends 18x12 with down fins on the side due to the limited stern area available to add larger tabs. Bennett doesn't make trim planes with larger than 12" chords. However, for those of us who have heavy dual I/Os with limited trim span areas, perhaps a 14" chord might be even better. I can get larger ones (18x14) made at local fab shop, but Bennetts have always been the chosen trim makers. Any suggestions???????.
 

alldodge

Moderator
Staff member
Joined
Mar 8, 2009
Messages
40,754
Re: Proper Trim Tab Size???????

I have about 12 or 14 inch wide by about 10 long on my Formula 27PC (28.2 long x 9.5 wide) and drafts 42 inches. Bennet says I should have 30 x something. I would measure the tabs but the boat is in the water and will be a few more days before I get back to it. They do very well and have no issues and my boat weights 9500 dry so I guess I'm coming in around 10500. Looking up your boat it comes in at 5000 dry.

Pro-Line 29 Super Sport | Salt Water Sportsman

What kind of power do you have?
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
Re: Proper Trim Tab Size???????

Do you have a photo of the boat's transom you can post?
 

Jdeagro

iboats.com Partner
Joined
Jul 30, 2003
Messages
1,682
Re: Proper Trim Tab Size???????

Hi Tom!

Are you Back? Hope So!
 

Tabman

iboats.com Partner
Joined
Feb 21, 2002
Messages
566
Re: Proper Trim Tab Size???????

Yup, I'm back! Got out of the hospital on Friday and feeling pretty good! Slowly coming back to speed on the forums.

The surface area of the Trim Tabs are a really important factor in the amount of lift they generate. Surface area, speed of the water flow, and angle of deflection are the three main factors.


A photo would help us see what will best fit your transom.
 
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