Cutwater - Trim Tabs too small

All things technical for Cutwater Boats. Post your questions and/or solutions for the Cutwater community here.

Re: Cutwater - Trim Tabs too small

Postby Tardis on Sat Nov 10, 2018 3:45 pm

Since my post on speed has generated some discussion, let me give some additional details.
I have a 2013 C28 with diesel D4 260 engine. It is loaded - AC and generator, etc. as it was briefly a dealer demo. I usually have 4 adults aboard, plus gear, so I am carrying a bit extra weight.
Engine spec is 3500 WOT. I can hit about 3350 with my prop when all is clean.
BoatTest ran an article on a similar C28 about 5 years ago and found top speed was 27 knots with a light load.
My experience is that I once was able to hit 24 knots, but not for long. In the warm waters here in SC fouling happens quickly. A diver cleans the hull at least every month in summer, but he cannot get everything. As you know, even a small amount of marine growth on the prop or a running surface will cut speed a good bit. My usually cruise is about 12 knots at 2700 rpm. According to the BoatTest performance table I should be doing about 17 knots at that rpm. so I have a lot of drag.
When I pulled the boat out last month I was horrified by all the marine growth (oysters, barnacles, grass) that was on the running surfaces, in both thruster tubes, and even partly into the exhaust (where the rubber covering flap is gone). Currently I am scheduled for bottom paint, and have given up my marina slip. Henceforth I will be keeping the boat in a dry stack, so I expect my performance to improve. Will not know for a while, though, as currently my engine is acting up - dropping back to 1500 rpm (safe mode?) whenever the rpm exceeds that. No error codes though, but that is another issue not worth pursuing until the hull is clean.
Tardis
 
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Non-Ranger Model: Cutwater 28
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Re: Cutwater - Trim Tabs too small

Postby BB marine on Thu Dec 20, 2018 8:22 am

I have listed a set of Bennett trim tabs complete, backing plate, hinge plate , custom drop fin, and planes (Cutwater for sale) If interested PM me.
Brian Brown
Cutwater 26
PORT-A-GEE
portageelooper.blogspot.com
bkb_marine@msn.com
BB marine
 
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Re: Cutwater - Trim Tabs too small

Postby BB marine on Wed Mar 20, 2019 8:34 pm

Over the winter I removed the factory installed Bennett trim tabs so that I could install larger planes. The trim tab original installation was not to Bennett installation specs ( mounted to high). Before installing the new 18x12 planes I filled the original fastener holes with west system epoxy and drilled new hole to move the planes to the proper mounting location 1/4" off the bottom leading edge, 5/8 " trailing edge. I spoke with a Bennett rep about benefits I experienced with the drop fins and asked about changing to the 18X12 so I could rack store the boat while in Florida. I was worried the forks from the truck would damage the drop fins. He felt that the benefit would be equal 12x12 plane with drop fin would = 18x12 without fins. I know of another Cutwater owner that did the same install and has realized the benefit. The 18 x 12 just fit. I'm posting a few pictures of the larger tabs installed.

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Brian Brown
Cutwater 26
PORT-A-GEE
portageelooper.blogspot.com
bkb_marine@msn.com
BB marine
 
Posts: 999
Joined: Mon Feb 01, 2016 10:30 pm
City: Lemont
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Re: Cutwater - Trim Tabs too small

Postby Cutwater28GG on Thu Mar 21, 2019 12:43 pm

be interested to hear how this tests in the water this year
Gavin - 2012 Cutwater 28
Image
Cutwater28GG
 
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Re: Cutwater - Trim Tabs too small

Postby BB marine on Thu Jun 13, 2019 5:34 pm

After three sea trials on Lake Michigan the larger 12 X 18 Bennett planes are a large improvement over the original installed 12 X 12 planes. I think they are equivalent to the custom drop fins that I made last year but I now do not have to worry about damaging the drop fins when I rack store the boat. Two week's ago we took a short 29 mile trip in what was forecasted as 1' to 3' with a 4 sec per. seemed closer to 2 to 4's. I'm cruising a bit stern heavy this year, Rib with 9.9 outboard, Aux fuel tank full, main fuel tank full, and additional weight from new Northstar AGM's 18lbs each heavier then original installed Centennial maintenance free. 72lbs more weight just in batteries. I was able to cruise and maintain 12.5 kts 3300 rpm with the bow down and cutting into the waves smoothly. I kicked the throttle up WOT 3980 18kts bow still down with a slight reduction in trim it still handled good with some hull pounding but very comfortable. I backed down to 3450 rpm the boat handled the short chop 1 to 3's nicely at 14kts. On the way back we had a following sea. I gained a bit 3450 rpm averaged 15kts and WOT was 4050 19.5 kts and an impressive smooth ride.( very little spray from the dingy ) I didn't want to back down on the throttle but the little D3 was screaming, so I backed down to 3450 maintaining 15kts. The additional weight added to the aft, 72lbs for batteries , 140 lbs fuel in aux tank full, 30lbs heavier outboard, 20lbs motor davit all added aft weight. I lost 100 rpm and 1.5 kts. I would loose considerably more if I was running standard 12 x 12 trim tab planes. I highly recommend larger planes or drop fins on the C26 if you plan on cruising with equipment on board or additional passengers.
Brian Brown
Cutwater 26
PORT-A-GEE
portageelooper.blogspot.com
bkb_marine@msn.com
BB marine
 
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Joined: Mon Feb 01, 2016 10:30 pm
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Re: Cutwater - Trim Tabs too small

Postby bill46 on Thu Jun 13, 2019 7:44 pm

I added Bennett fins to my tabs, improved R31CB performance.
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