boats3po
New Member
need to know about trim tabs and how they work, whats their function, how and whem to use them, the auto switch. thanks in advance for the info people. :smt100
trim tabs
- Thread starter boats3po
- Start date
JimG
Well-Known Member
- Nov 4, 2008
- 6,085
- Boat Info
- 2007 310 DA
Kohler 5ECD
- Engines
- Twin 350 Mags
Raw Water Cooled
V-Drives
Their primary uses are to help plane off quicker and to level the boat while at cruising speed for uneven loads. I also use them to make the boat turn quicker. Don't know anything about the auto switch you refer to.
Last edited:
mwph
Well-Known Member
- Jul 8, 2008
- 3,229
- Boat Info
- 1998 250 DA
- Engines
- 7.4L, B3
Pretty straight forward stuff but dozens of different situations lead to dozens of answers. The advanced search feature found around 75 threads on the subject. Plenty of good reading. Below is a sample...
http://clubsearay.com/forum/showthread.php?t=31509&highlight=tabs
http://clubsearay.com/forum/showthread.php?t=31509&highlight=tabs
- Oct 3, 2006
- 4,404
- Boat Info
- 280 Sundancer, Westerbeke MPV generator
- Engines
- twin 5.0's w/BIII drives
In addition to the above, when properly used trim tabs can help you hold plan at a slower speed. They can also help you drive the bow down further then it would be without trim tabs. In rough seas with a short or confused chop this slower speed bow down combination helps reduce the hard banging you get when the boat goes over the top of one wave and falls in the hole or trough between the peaks.
Tabs also allow you to level the boat from once side to another. This helps when the load inside the boat is uneven due to people sitting in various locations or wind and waves are causing the boat to be uneven in its ride.
Tabs also allow you to level the boat from once side to another. This helps when the load inside the boat is uneven due to people sitting in various locations or wind and waves are causing the boat to be uneven in its ride.
bigblockcutlass
Member
- May 9, 2010
- 832
- Boat Info
- 1998 Carver 370 Voyager
1990 270 sea ray sundancer twin 4.3L
1987 Power Play 230 Conquest
1987 Fo
- Engines
- 454
Get them!!! they will be worth it. This is my second boat with them on and there worth having. I did buy inductors for them, so I know were there at. Seem easier to make small adjustments wile cruising. Sometime's the boat don't react quickly and only a small adjustment is needed. With the inductor's you can make a small adjustment and see they moved and wait a few seconds before the boat actually moves. Also will keep you from dead heading the pump. When you see there down on the inductor's, you quit pushing the button to make sure there down or up.
Tabman
Member
boats3po,
Here is some basic information on how Trim Tabs work and how to use them. Take a look and let me know if you have any questions,
Tom McGow
Bennett Marine
Properly sized trim tabs improve the performance of your boat in a much wider range of weight, weather and water conditions. The purpose of trim tabs is to recreate your ideal running attitude, even on a rough day.
Think ailerons and elevators on an airplane. Trim tabs do much the same thing for a boat - providing lift to compensate for changing conditions.
How Trim Tabs Work Three variables combine to affect lift:
• Size of the trim tab surface
• Angle of deflection
• Water-flow over the tab (caused by speed of the boat)
When the helm control is pressed, the trim tabs move into position. When they are deflected downward, the water force on the trim tab surface creates upward pressure, raising the stern and lowering the bow.
Reverse Operation Don't Worry About Which Trim Tab is Moving
Trim Tabs operate the reverse of what you might think. The port trim tab lowers the starboard bow. Conversely, the starboard trim tab lowers the port bow. The control is wired so that all you have to do is press the control in the direction you want the bow to move. The proper use of Trim Tabs becomes second nature after a short time.
Here is a little information on how to use Trim Tabs;
Getting and Staying Trimmed
All boats assume different fore to aft attitudes at different throttle settings and vary in sensitivity to lateral weight distribution.
A boat’s optimum running attitude is determined by the operator. While some people may define optimum running attitude as the highest possible speed for a given amount of engine RPMs, others desire the best possible fuel economy, yet others may be trimming the boat to get just the right mix of speed and wake (such as for waterskiing.)
Optimum running attitude is when the boat is running to the operator’s satisfaction for the given operating conditions. There are as many optimum running attitudes as there are boats and boat owners
A good way to determine a boats optimum running angle (see side bar Optimum Running Attitude) is to run the boat lightly loaded at full speed in calm water. During this test observe the boat’s bow in relation to the horizon. Most boats run at or near their optimum attitude under these conditions. This should give you a feel for the appearance of the wake and bow spray when running at an efficient attitude. Note that not all boats will achieve their optimum running attitude under these conditions. Some boats will benefit from extra lift even when running at their maximum throttle settings. If you feel the boat will benefit from added bow down trim when running at speed start with the trim tabs fully up and deflect the trim tabs in short bursts. Be alert to changes in the boats handling, as you bring the bow down. Observe any changes in RPMs and/or speed. Adjust power trim if applicable.
Indications of Running Untrimmed
When a boat is running untrimmed the bow spray will exit the sides of the boat far aft. The stern wave (wake) is high and curling like a breaker on the beach. The rooster tail is high and close to the stern. The engine is laboring and the ride tends to be less smooth.
Indications of Running Trimmed
The bow spray moves forward and is flung not as far from the boat. The wake diminishes in height, as the rooster tail flattens out and moves away from the boat. The engine is operating under less load as evidenced by the tachometer and speed as well as sounding “less strained”.
One Step at a Time
The key to obtaining optimal results from trim tabs is to operate them in short “bursts” and let the boat react before making another adjustment. The amount of time between corrections is influenced by the size of the trim tabs and the boat’s speed. This will help avoid overtrimming or ending up with one tab too far down when correcting lateral trim. You will quickly become acquainted with a boat’s particular traits.
Take Off
Properly sized trim tabs can significantly reduce the time needed to get up on plane. They also allow a boat to keep its bow down and stay on plane at lower speeds.
As the throttle is advanced the stern of the boat begins to squat, lifting the bow. As the boat accelerates, push the bow down position of the helm control in short bursts. The boat reacts by the stern lifting, the bow coming down, speed increasing, and reduced engine laboring. If you over do it and deflect the tabs too far the boat will end up overtrimmed. When over trimmed, the steering becomes “over sensitive” and wants to pull off course to port or starboard. If this occurs, operate the control “bow up" until the desired attitude is established.
Getting the Most from Power Trim
Adjust the trim tabs to achieve the desired running attitude. Then use the power trim to position the propeller thrust parallel to the water flow. If necessary, re-adjust the trim tabs to fine tune the attitude. By observing the boat’s speed and engine RPMs the best combination of trim tabs and power trim will be apparent. Trim tab angle indicators and a power trim angle indicator are particularly useful in duplicating effective settings.
Trimming to Sea Conditions
When running into a head sea you want to trim the bow down so the sharp forward sections of the boat do their work cleaving the waves. This provides the most comfortable ride and minimizes stress on the boat (and passengers). In a following sea the tabs should be fully retracted for maximum steering response.
Correction of a List
The normal control setup for trim tabs operates in relation to the desired changes in trim and not the actual movement of the tabs. Therefore, do not think about what the tabs are doing, but rather on the control and what you want the boat to do. As above, make the corrections in bursts and allow the boat to settle to the new settings. You may find it easier to correct the boat’s fore and aft attitude before you correct the side to side trim.
Correction of Porpoising
Operate the tabs in very short bursts of about half a second. Continue until porpoising subsides. The objective is to have only a very slight amount of tab deflection, just the amount needed to cure the up and down motion of the bow.
Here is a link to our Trim Tab simulator you can download and run on your computer;
http://www.bennetttrimtabs.com/simulator.htm
Here is some basic information on how Trim Tabs work and how to use them. Take a look and let me know if you have any questions,
Tom McGow
Bennett Marine
Properly sized trim tabs improve the performance of your boat in a much wider range of weight, weather and water conditions. The purpose of trim tabs is to recreate your ideal running attitude, even on a rough day.
Think ailerons and elevators on an airplane. Trim tabs do much the same thing for a boat - providing lift to compensate for changing conditions.
How Trim Tabs Work Three variables combine to affect lift:
• Size of the trim tab surface
• Angle of deflection
• Water-flow over the tab (caused by speed of the boat)
When the helm control is pressed, the trim tabs move into position. When they are deflected downward, the water force on the trim tab surface creates upward pressure, raising the stern and lowering the bow.
Reverse Operation Don't Worry About Which Trim Tab is Moving
Trim Tabs operate the reverse of what you might think. The port trim tab lowers the starboard bow. Conversely, the starboard trim tab lowers the port bow. The control is wired so that all you have to do is press the control in the direction you want the bow to move. The proper use of Trim Tabs becomes second nature after a short time.
Here is a little information on how to use Trim Tabs;
Getting and Staying Trimmed
All boats assume different fore to aft attitudes at different throttle settings and vary in sensitivity to lateral weight distribution.
A boat’s optimum running attitude is determined by the operator. While some people may define optimum running attitude as the highest possible speed for a given amount of engine RPMs, others desire the best possible fuel economy, yet others may be trimming the boat to get just the right mix of speed and wake (such as for waterskiing.)
Optimum running attitude is when the boat is running to the operator’s satisfaction for the given operating conditions. There are as many optimum running attitudes as there are boats and boat owners
A good way to determine a boats optimum running angle (see side bar Optimum Running Attitude) is to run the boat lightly loaded at full speed in calm water. During this test observe the boat’s bow in relation to the horizon. Most boats run at or near their optimum attitude under these conditions. This should give you a feel for the appearance of the wake and bow spray when running at an efficient attitude. Note that not all boats will achieve their optimum running attitude under these conditions. Some boats will benefit from extra lift even when running at their maximum throttle settings. If you feel the boat will benefit from added bow down trim when running at speed start with the trim tabs fully up and deflect the trim tabs in short bursts. Be alert to changes in the boats handling, as you bring the bow down. Observe any changes in RPMs and/or speed. Adjust power trim if applicable.
Indications of Running Untrimmed
When a boat is running untrimmed the bow spray will exit the sides of the boat far aft. The stern wave (wake) is high and curling like a breaker on the beach. The rooster tail is high and close to the stern. The engine is laboring and the ride tends to be less smooth.
Indications of Running Trimmed
The bow spray moves forward and is flung not as far from the boat. The wake diminishes in height, as the rooster tail flattens out and moves away from the boat. The engine is operating under less load as evidenced by the tachometer and speed as well as sounding “less strained”.
One Step at a Time
The key to obtaining optimal results from trim tabs is to operate them in short “bursts” and let the boat react before making another adjustment. The amount of time between corrections is influenced by the size of the trim tabs and the boat’s speed. This will help avoid overtrimming or ending up with one tab too far down when correcting lateral trim. You will quickly become acquainted with a boat’s particular traits.
Take Off
Properly sized trim tabs can significantly reduce the time needed to get up on plane. They also allow a boat to keep its bow down and stay on plane at lower speeds.
As the throttle is advanced the stern of the boat begins to squat, lifting the bow. As the boat accelerates, push the bow down position of the helm control in short bursts. The boat reacts by the stern lifting, the bow coming down, speed increasing, and reduced engine laboring. If you over do it and deflect the tabs too far the boat will end up overtrimmed. When over trimmed, the steering becomes “over sensitive” and wants to pull off course to port or starboard. If this occurs, operate the control “bow up" until the desired attitude is established.
Getting the Most from Power Trim
Adjust the trim tabs to achieve the desired running attitude. Then use the power trim to position the propeller thrust parallel to the water flow. If necessary, re-adjust the trim tabs to fine tune the attitude. By observing the boat’s speed and engine RPMs the best combination of trim tabs and power trim will be apparent. Trim tab angle indicators and a power trim angle indicator are particularly useful in duplicating effective settings.
Trimming to Sea Conditions
When running into a head sea you want to trim the bow down so the sharp forward sections of the boat do their work cleaving the waves. This provides the most comfortable ride and minimizes stress on the boat (and passengers). In a following sea the tabs should be fully retracted for maximum steering response.
Correction of a List
The normal control setup for trim tabs operates in relation to the desired changes in trim and not the actual movement of the tabs. Therefore, do not think about what the tabs are doing, but rather on the control and what you want the boat to do. As above, make the corrections in bursts and allow the boat to settle to the new settings. You may find it easier to correct the boat’s fore and aft attitude before you correct the side to side trim.
Correction of Porpoising
Operate the tabs in very short bursts of about half a second. Continue until porpoising subsides. The objective is to have only a very slight amount of tab deflection, just the amount needed to cure the up and down motion of the bow.
Here is a link to our Trim Tab simulator you can download and run on your computer;
http://www.bennetttrimtabs.com/simulator.htm
boats3po
New Member
yes, thank you , alot to learn, thank GOD i got a wealth of knowledge with you guys, Enjoy your Holidays if you think of anything else for a new boater fee free to drop me a line