Can i make these trim tabs bigger?

I have a 2002 340 only pic I have it tabs is this.
I also have to ask the down bolt ons how will that work when you slide it on a trailer...

You won't be sliding a boat that far up a trailer that the tabs would (or should) contact anything.
 
Every boat I have ever loaded correctly, the bunks go past the transom. Other wise it can cause hook in the hull. Granted this kind of boat lives in the water. But I will want to be able to pull it on the trailer for cleanings and travel.
 
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I did drop fins first and see what that did... It Def helps and i do notice a big difference. Thanks Tab man...

View attachment 57989 View attachment 57990
Siboatguy - you should probably look to change those swim platform bolts sooner than later - Looks like an advanced case of crevice corrosion going on. Use 316 SS replacements with ample sealant.
 
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Bennett recommended drop fins on my tabs. They told me it should make my tabs act like the next size larger. Turned out to be the single best mod I have done to my boat. The bow rides lower and I have picked up about 1.5-2 kts. I could still use more tab but for $34. Thank you very much!
 
Bennett recommended drop fins on my tabs. They told me it should make my tabs act like the next size larger. Turned out to be the single best mod I have done to my boat. The bow rides lower and I have picked up about 1.5-2 kts. I could still use more tab but for $34. Thank you very much!
What size are your tabs and which drop fins did you install? Sounds like a nice off season mod.
 
Bennett recommended drop fins on my tabs. They told me it should make my tabs act like the next size larger. Turned out to be the single best mod I have done to my boat. The bow rides lower and I have picked up about 1.5-2 kts. I could still use more tab but for $34. Thank you very much! I don't recall dimensions of my tabs. They are stock equipment. The kit I added was Bennett drop fin DF12. I would give them a call. They can verify.
 
Bennett recommended drop fins on my tabs. They told me it should make my tabs act like the next size larger. Turned out to be the single best mod I have done to my boat. The bow rides lower and I have picked up about 1.5-2 kts. I could still use more tab but for $34. Thank you very much! I don't recall dimensions of my tabs. They are stock equipment. The kit I added was Bennett drop fin DF12. I would give them a call. They can verify.

My boat is out of the water how and I’m seriously considering adding the drop fins.
If you take yours out of the water, could you possibly post pictures and measurements of your tabs with the drop fins on them?
 
Sorry, haven't spent much time here lately. I will try to get to the boat this weekend and post a picture.
 
Small update. My tabs are ready to put in waiting on haul out to install.

After bends and all. They are 24” wide and 14” long. Have 2.5 inch drop fins with a angle that meets full length at 4”. Also a 1 “ rear up bend for lateral strength.

All made out of single sheet of 304 stainless. Plan to weld to the bottom of factory tabs.

Going on a 2002 340 with 8.1s
Factory tabs are 12x14 without fins.

Hopefully this should give me the ability to ride flatter, and maybe quicker with less drag...
 

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Boat comes out tomorrow, going to try and slide the factory tabs off with out removing the screws into the hull. I think bennet uses a small tab bent farher then the hinge bend to keep tabs in place left to right, and hoping I can bend one tab, and slide tab out to work on it, and then slide back in and bend tab back...

welding with the correct stainless wire, and then will be bottom painted back over them. So front side should be solid matted surface, with grind smooth and then stiching welds on sides and back will be on to top side.
 
Boat comes out tomorrow, going to try and slide the factory tabs off with out removing the screws into the hull. I think bennet uses a small tab bent farher then the hinge bend to keep tabs in place left to right, and hoping I can bend one tab, and slide tab out to work on it, and then slide back in and bend tab back...

welding with the correct stainless wire, and then will be bottom painted back over them. So front side should be solid matted surface, with grind smooth and then stiching welds on sides and back will be on to top side.


Have you looked into the "drop Fins"? they are a lot less work.
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Well they are on. Bottom pressure washed and sanded waiting on bottom paint.

Work, and attached. My only concern is the drop fins. If I had bolted on drop fins I would have the same worry. As the back of the boat looks flat. But once everything is mated up. Each tabs fins are barley facing inward... square with the tab so drop fins bolted would have been same as well. And maybe it’s how the water will spit by the hull and hit the tab.. but they are not facing the same exact dowsed direction. Euall and square with tab mounting yes.. anyway.

Hopefully few mph, and some flatter riding.
 

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No comments omn the drop fins direction? pointing strait forward or square with the side of the tab?
 
The stern of the boat is not flat, and has a curve.. this the tabs don’t deploy 100% backward they have a little outward movement.. and when you add drop fins they are not strait with the flow of water.... and this will cause drag, and alotmof extra pressure against the mounting plate/hinge. I removed the tabs, and cut my drop fins back off..

Will reinstall just the larger tabs tomorrow. Not worth the risk and time to renounce boat or damage transom. 55% larger tabs will help.
 
Pulled them last night, cut drop fins back off. Smoother edges, reinstalled tabs. Still have a lot more surface and chore. But drop fins would cause drag and issues with this hulls stern.
 

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The stern of the boat is not flat, and has a curve.. this the tabs don’t deploy 100% backward they have a little outward movement.. and when you add drop fins they are not strait with the flow of water.... and this will cause drag, and alotmof extra pressure against the mounting plate/hinge. I removed the tabs, and cut my drop fins back off..

Will reinstall just the larger tabs tomorrow. Not worth the risk and time to renounce boat or damage transom. 55% larger tabs will help.

that runs 100% contrary to the engineer from Bennett's advice. The drop fins are specifically recommended over additional chord or width unless you change the mounting, hinge, and actuators. Best of luck to you on your modification. I'm sticking with the professional's advice on this one.
 

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