Trim Tabs

DoryJean- parrott · Posted: Wed Jul 09, 2008 8:40 am Post subject: Trim Tabs

Hello everyone. My name is David Parrott.........My father was Dr. Frank Parrott who passed away a few weeks ago. Cry

He Loved this boat of his, the C-Dory. He always wanted to get trim tabs on the boat.....It is a 22" Cruiser.........Does anyone have, or suggestions for what type to put on there.......I need some feed back...............My dad loved this boat and it even kept him going through the bad times........I am going to keep his dreams going and remember his love for boating
David Parrott

rogerbum · Posted: Wed Jul 09, 2008 8:47 am Post subject:

David,

Sorry to hear about your dad but am pleased to see you will continue the tradition as the family C-brat. Trim tabs have been extensively discussed on the site before and you can find many of the discussions by using the search feature.

Here's a couple of links to previous discussions to get you started.

http://www.c-brats.com/viewtopic.php?t=8428&highlight=trim+tabs
http://www.c-brats.com/viewtopic.php?t=7134&highlight=trim+tabs

DoryJean- parrott · Posted: Wed Jul 09, 2008 8:57 am Post subject:

I thought that it has...THat is the reason i wanted to get in touch with a few other C-Dory Brats................SO do you have them on your boat and if so did it help.....

flapbreaker · Posted: Wed Jul 09, 2008 9:13 am Post subject:

Jazzmanic · Posted: Wed Jul 09, 2008 12:55 pm Post subject:

Our Bennett trim tabs are the M120's. I think they're the same as Spencer's pictured above. As Tyboo says, it's almost as if they're designed for C-Dory's. Here's a pic of ours mounted on the boat. The bracket is called a Mini-Jacker. I know the factory had some available during the factory party in January. You might want to call them.

David, I'm sorry to hear of your father's passing. I'm sure he would be pleased to know you're carrying on the C-Dory tradition.

jlastofka · Posted: Thu Jul 10, 2008 3:52 pm Post subject: Trim tab running angle

I have the standard Bennet trim tabs the factory installs on my CD22. I have a Honda 90 and 9.9 and I find I run with the tabs down about 35 or 40% judging by the indicator, with some side to side variation depending on boat loading. Seems the boat makes the most MPH per RPM in that area, and things just feel right.....

As noted by others, I'll sometimes force the bow down more running into chop (helps ride quality a LOT) and more bow up if I'm overrunning waves downwind (down swell....)

I'll bet that moving as much weight as possible forward in the boat and running less tab deflection would reduce drag and help efficiency. Not sure I'll get around to doing that, though.

Where do other people run their tabs most of the time? Retracted, part way down, lots of down?

Jeff

flapbreaker · Posted: Thu Jul 10, 2008 4:06 pm Post subject:

I always run with mine probably 1/4 to 1/2 way down. Not only is the ride smoother but the fuel economy is better.

Zelpha · Guest

From past experience, on some boats all down on Bennett tabs can cause broaching (18 ft Dory). Was I ever scared! In my opinion they are the greatest addition to trim however. Zelpha

Zelpha · Guest

Also once built a LUGAR 22 ft fiberglass cruiser from a kit (much like the 22 C-Dory only with a very deep-V hull). Was it ever prone to broach. Once returning from Santa Rosa Island to Santa Barbara in that boat in the afternoon (gets very rough there with high short wavelength waves) my two passengers (one a Boeing SST engineer) were found in the cabin holding a prayer vigil. Broaching is a one-time experience. Zelpha

Hunkydory · Posted: Thu Jul 10, 2008 10:51 pm Post subject:

Set the moter trims so props are aligned with boat bottom then use Bennett trim to adjust by gps best speed for any given rpm. This usually is about a 12 to 15 out of a max 20 on the trim gauges. Can differ much from usual depending on speed, total weight and weight distribution. When heavily loaded on a long cruise especially with the extra fuel in cockpit run trims maxed out most all the time, except at displacement speed when if left fully down they will slow the boat by about .5 mph which doesn't sound like much, but at 5 mph it could mean a 10 % loss in fuel economy or range, so I now try to remember to fully retract when just easing along.

Jay