Can i make these trim tabs bigger?

Discussion in 'Bennett Trim Tabs Vendor Forum' started by Siboatguy, Jan 21, 2018.

  1. Siboatguy

    Siboatguy Member GOLD Sponsor

    146
    Mar 28, 2016
    Holmdel,NJ
    2005 Sea Ray 320 Sundancer
    Twins V-Drives
    2017 5.7 Mercruisers
    Is there anyway i can make my tabs bigger from (bow to stern)? And will that help?? I have a sea ray 320 props are redone. This year im gonna add 4 blades... I notice i always run bow high and gotta run at 3900 to stay on plane with out the ass sitting down... Was thinking of just welding a piece of stainless steel sheet metal on the bottom of it and turning the sides down?? If i change the trim tab and make it longer i was worried the piston won't be long enough... tabs1.jpg tabs2.jpg
     
  2. Gofirstclass

    Gofirstclass Well-Known Member GOLD Sponsor

    Apr 20, 2010
    Tri Cities, WA
    1995 550 Sedan Bridge,
    2010 Boston Whaler 130 Super Sport,
    1981 Boston Whaler 130 Sport,
    CAT 3406C's, 580hp.
    I had my trim tabs enlarged both front-to-back and side-to-side. I also had a hull extension made to increase the running surface of the hull but that was not done for increased lift.

    So, the simple answer to your question is "yes you can" enlarge the tabs.

    [​IMG]
     
  3. FootballFan

    FootballFan Well-Known Member GOLD Sponsor

    Jun 20, 2012
    Florida
    Marquis 59
    MTU Series 60
    There is a guru of Tabs that is on several forums.

    Tabman

    I would see if you could get his input. Have seen him on here and some other forums. He helped me with some tab reconfiguration work last fall. He knows his stuff.

    Mark
     
  4. Siboatguy

    Siboatguy Member GOLD Sponsor

    146
    Mar 28, 2016
    Holmdel,NJ
    2005 Sea Ray 320 Sundancer
    Twins V-Drives
    2017 5.7 Mercruisers
    I'm hoping i hear from him tabman.... I would love to hear his input on it... Thanks again everyone for all the help....

    If i do add to it... curious if i should turn down the sides and if so how much and how much to add on... How much can the pistons handle...
     
  5. juggernaut1

    juggernaut1 Member PLATINUM Sponsor

    668
    Apr 19, 2015
    Perth, Western Australia
    2006 38 Sundancer
    8.1S / ZF 63V Drives
  6. Tabman

    Tabman Member

    658
    Jan 11, 2007
    The Tab Cave
    boatless
    boatless
    While I seen successful instances of adding chord (fore to aft) to tabs by adding an extension to them, I can't "officially" recommend it. While the actuators are very strong, they can be damaged by the additional leverage. Particularly when backing down, as water "piles up" on top of the tab. This is exacerbated when there is a platform on the transom that forces even more water down when in reverse. 12" chord Tabs are the maximum we recommend.

    The addition of 3" drop fins is a good idea.

    Also I don't recommend welding as it invites corrosion.

    One idea would be to add Tabs over the prop tunnels and simply tee them into the existing actuators on either side.

    I hope this helps,

    Tom McGow
    Bennett Marine
     
  7. Siboatguy

    Siboatguy Member GOLD Sponsor

    146
    Mar 28, 2016
    Holmdel,NJ
    2005 Sea Ray 320 Sundancer
    Twins V-Drives
    2017 5.7 Mercruisers
    Thanks so much for looking into this tom (Tabman) The tabs over the prop tunnels don't know if i wanna get into that much work this year... Lets say i leave them that size maybe only go 3inchs longer but mostly add the drop fins.. Do you see a big difference from just drop fins? Ill just bolt on to the org trim tab.. unless i should buy a hole new tab?
     
  8. Tabman

    Tabman Member

    658
    Jan 11, 2007
    The Tab Cave
    boatless
    boatless
    They help quite a bit. The Bennett part number for them is DF12 https://www.defender.com/product.jsp?path=-1|2331321|2331349|2331353&id=2393734

    Tom
    Bennett Marine
     
  9. frosh coach

    frosh coach Member

    136
    Apr 20, 2011
    Long Island Sound, New Haven CT
    1994 300 Sundancer
    1989 230 Cuddy (SOLD)
    Twin Mercruiser 350 FWC, Alpha 1 Gen II
    I had 1/8" stainless plates made that I drilled and bolted to my existing tabs. The plates were about 4” wider, and 2” larger fore to aft. I also added the 3” drop downs as tab man suggested. This helped. I have a 30’ with twin i/o’s and a generator. There’s a lot of weight in the back end. I still run around 3500 though. The big difference is getting on plane when I’m loaded up.
     
  10. BillK2632

    BillK2632 Well-Known Member SILVER Sponsor

    Jun 25, 2009
    Lake Norman, NC
    1999 185 Bowrider,
    Mercruiser 4.3, Alpha I
    Something else kinda odd on your tabs, looks like the anode is mounted on the bottom of the tab, not the top?
     
  11. hottoddie

    hottoddie Well-Known Member

    Jan 11, 2012
    Boston/Cape Cod
    1986 Sea Ray 390 Express
    Garmin 4212 Chartplotter
    Garmin 24 HD Radar
    Garmin GSD 22 Sounder
    Garm
    454 Crusaders
    I see that all the time. Standard procedure is to install on the top of the tab only. Putting one on the bottom interrupts the flow of water and reduces the effectiveness of the tab.
     
  12. Strecker25

    Strecker25 Well-Known Member SILVER Sponsor

    Nov 20, 2014
    Rochester, NY
    1998 290 Sundancer
    Twin 5.7EFI/Alphas, Kohler 4kw
    Smaller boat and with IO so sort of apples to oranges but I added the drop fins to our 290 in combination with 4 blade props and dropped min planning rpms by about 500
     
  13. Doc O Rock

    Doc O Rock Member GOLD Sponsor

    180
    Mar 23, 2016
    Lake St Clair, Belle Maer Harbor
    1999 380 Sundancer
    twin 7.4 Merc

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