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Planing a 2450 Sunbridge-gctid398566

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    Planing a 2450 Sunbridge-gctid398566

    Not too long ago I started a thread about how long it took my 86' Ciera Sunbridge 2450 to get up to plane on my local lake.

    http://www.baylinerownersclub.org/fo...first-time-out

    Well, I did some research and according to the Bennett trim tabs site the tabs I had on my boat were undersized. It said that I needed 18"x9" tabs and I had 12"x7" tabs. Using that information I made some tabs at work out of aluminum that I could attached to the tabs that were currently there. I did this because I didn't have an aluminum or stainless steel piano hinge. The tabs looked great and were very solid when attached. After some other needed repairs (replacing the entire tilt mechanism) I was able to take the boat out again this week out in Bellingham Bay. I put the trim tabs down all the way and gave her the gas. All she wanted to do was plow the water. My brother ended up climbing on the bow to get her to plane. Not the results I was hoping for. Since this was the sea trial for all the systems we kept running for awhile. After a half hour we stopped the boat. I don't know why but when we started going again my brother decided to have the trim tabs all the way up. Well, the results were much different. We jumped right up to plane without any problems. We tried this a few other times and it worked every time. I was amazed yet skeptical. When we got back to shore and had the boat on the trailer we tested to see how the trim tabs were working, our thinking being that perhaps the switches were wired backwards. Everything tested fine, up is up and down is down.

    Now, I'm not complaining at all, but I'm just a bit confused. It only seems natural that when the trim tabs were down all the way that the boat would plane faster, but it didn't. Likewise, it would seem that it would be difficult to plane with the trims tabs all the way up but that wasn't the case. Has anyone else experienced this before? Everything else ran great. The motor was strong and ran well. I can't wait to get her out fishing for a weekend.

    #2
    The tabs are an extension of the running surface of the hull. Perhaps the added length was all it needed. In most cases one needs to use the tabs to push the bow down to get up on step quicker than no tabs, maybe not in yours.

    The end results are what you were after.

    Enjoy the fishing.
    Phil, Vicky, Ashleigh & Sydney
    1998 3055 Ciera
    (yes, a 1998)
    Previous boat: 1993 3055
    Dream boat: 70' Azimut or Astondoa 72
    Sea Doo XP
    Sea Doo GTI SE
    Life is short. Boats are cool.
    The family that plays together stays together.
    Vice Commodore: Bellevue Yacht Club

    Comment


      #3
      MadViking,

      Can you tell me what the span (side to side) and chord (fore to aft) measurements of your new Trim Tabs are?

      itsabowtime2 is on target with what is probably occurring! I am just curious what size you have now.

      Tom

      Bennett Marine
      sigpic"Like" Bennett Marine on Facebook

      Comment


        #4
        Perhaps the extended length also created drag when fully extended?

        Next time, try planing the boat off with just a bump of tab-down (not fully extended) and then once she's up, pull the tabs up again.

        I still suspect motor trouble. 2 people on a 5.0L 2450 should plane off without tabs, and in less than 30 seconds. Maybe I am wrong, but if I could get my 2450 with a 5.7 in it (and 10 people) planed off with no tabs, you should too.
        Matt Train
        BOC Site Team
        Chicagoland, IL

        Comment


          #5
          I find it odd that you would even need trim tabs to get on plane. I have an '88 2455 and the only time I feel the need to use the tabs is to counter balance the load when I have a bunch of people on the "L" seat.

          Comment


            #6
            Wingnutt wrote:
            I find it odd that you would even need trim tabs to get on plane. I have an '88 2455 and the only time I feel the need to use the tabs is to counter balance the load when I have a bunch of people on the "L" seat.
            ^^

            What he said. You should be able to plane a 1980s 2450 off with NO tabs, regardless of engine.
            Matt Train
            BOC Site Team
            Chicagoland, IL

            Comment


              #7
              Tom, the span is 18" and the chord is 9". The originals were 12" by 7".

              I see what everyone is saying, you should be able to get up to plane without the tabs and apparently it does just fine but I would still suspect that with the tabs down it should help bring the bow down quicker. Again, I'm not complaining, I was just curious.

              Comment


                #8
                Surely it is the outdrive trim that is significant in all this not the trim tabs. Trim tabs are primarilly there to control trim not pitch as I understand.

                I have a 2452 and it basically gets on the plane with its 5.0L engine quite easilly. However, to save a "slog" I trim the outdrive down (in) to speed up the process. I used to trim the tabs right down years ago but I don't bother any more. I have noticed that an uneven trim makes planing more difficult. I guess this is because the flat patch on the hull (someone will know the proper name) isn't flat on the water.

                I put the trim tabs down when manoeuvring at low speed to act as a brake. I wonder if this slowing your forward momentum enough to affect getting on the plane.

                I did read a 'getting on the plane user-guide' once. It went something like this:
                • Trim outdrive all the way down;
                • Trim tabs all the way down;
                • In gear and rev to 3000 RPM (personally I'd go for 3400);
                • When the revs start to climb (a sign of coming onto the plane) tilt the outdrive to releive the engine of some strain (gets you more revs without




                touching the throttle);

                If this is what you do already please accept my apologies for the needless repetition.

                At the risk of being long-winded. If I ever have trouble getting on the plane the first thing I look for is a very thin layer of green-slime on the hull. An unbelievably small amount of this sh1t causes enormous drag, far more than a proper weed plant growing on the trim tabs and outdrive. I get these all the time and just ignore them I can never ignore green-slime.

                Terry
                Terry (Retired Diving Instructor and Part Time IT Consultant)
                1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
                MMSI 235061726

                Comment


                  #9
                  Trim tabs are primarilly there to control trim not pitch as I understand.
                  Depends on the boat. My 3055 runs best if the tabs are used generously to keep the bow down at normal cruise speed. It is both more comfortable/stable and more efficient according to my fuel flow meters.

                  My previous boat was a 2001 2455 and it would plane fine without tabs with a couple people on board, but once you got to four or five the tabs really helped. And in any case, its time to plane was always reduced by using the tabs. That one ran best with 15% tab at cruise speed.

                  Comment


                    #10
                    Early Volvo Pentas (most of the people on this site fall into this category) do NOT have power trim. The drive is either down, or up.
                    Matt Train
                    BOC Site Team
                    Chicagoland, IL

                    Comment


                      #11
                      What position is the "pin" in on the outdrive? There are 3 positions, and it normally should be in the middle hole.

                      Comment


                        #12
                        SwampNut wrote:
                        Depends on the boat. My 3055 runs best if the tabs are used generously to keep the bow down at normal cruise speed. It is both more comfortable/stable and more efficient according to my fuel flow meters.

                        My previous boat was a 2001 2455 and it would plane fine without tabs with a couple people on board, but once you got to four or five the tabs really helped. And in any case, its time to plane was always reduced by using the tabs. That one ran best with 15% tab at cruise speed.
                        Cool. We are learning some stuff here.
                        Terry (Retired Diving Instructor and Part Time IT Consultant)
                        1998 Bayliner 2452. 5.7l V8 - Edelbrock 1409 4bbl - Alpha1Gen2 - Solent UK.
                        MMSI 235061726

                        Comment


                          #13
                          I don't have the power trim, just a tilt to raise the outdrive for trailering. The pin for the outdrive lock is in the middle hole.

                          Comment


                            #14
                            What is your wide-open RPM, and speed?
                            Matt Train
                            BOC Site Team
                            Chicagoland, IL

                            Comment


                              #15
                              This might just be my humble confusion, but I'd like to go back and clarify a few things.

                              You said:

                              MadViking wrote:
                              I put the trim tabs down all the way and gave her the gas. All she wanted to do was plow the water. My brother ended up climbing on the bow to get her to plane.

                              Not the results I was hoping for. Since this was the sea trial for all the systems we kept running for awhile. After a half hour we stopped the boat. I don't know why but when we started going again my brother decided to have the trim tabs all the way up. Well, the results were much different. We jumped right up to plane without any problems. We tried this a few other times and it worked every time.
                              I'm not quite following what you're saying by plowing through the water. If you mean bow too high, that would be the opposite effect of what the trim tabs would do if they were indeed all the way down. Tabs down would push the bow down. Yet, if you meant the opposite of that, and that the bow was being pushed down too far, then I'm not sure how your brother climbing up on the bow would have made it any better. Thus, I'm a bit confused as to what was happening.

                              You also said:

                              MadViking wrote:
                              When we got back to shore and had the boat on the trailer we tested to see how the trim tabs were working, our thinking being that perhaps the switches were wired backwards. Everything tested fine, up is up and down is down.
                              I also want to clarify your switches, as it can be confusing, particularly depending on how the switches are mounted (vertical, horizontal, etc....). If memory serves correctly, my previous 1985 2450 Ciera's tab switch assembly was mounted nearly vertical and to the right of the steering wheel, meaning there was a "top" and "bottom" to the switches (as opposed to horizontal mounting and front/back orientation). Pushing the top, UP, on the switches makes the tabs go DOWN, which makes the bow go DOWN. Pushing the bottom of the switch, or Down, makes the tabs go UP and the bow goes up. Thus, if the switches are mounted vertical or at an incline, and you push the top of the switch, it does not necessarily mean up.

                              Moreover, the tabs are affecting the back of the boat too, not just the bow. Pushing the tabs down also simultaneously lifts the back of the boat higher out of the water. Conversely, raising/retracting the tabs causes the back of the boat to drop further into the water.

                              I apologize if you already understood the operation of the switches, but I wanted to point it out because it is a common issue of confusion. It's also possible the switches have since been re-wired/mis-wired or the actual UP/DOWN labels have worn off etc....

                              My 1985 2450 had an AQ225 in it (D I think), and it had no problems getting up on plane. I wouldn't say it had great hole shot, but I wasn't concerned about that anyway (I don't pull skiers etc...). My 305 V8 was stock and I had the stock prop (sorry, forgot the size). I think I mentioned it in your other post, but I am also of the belief that Bayliner typically used undersized trim tabs on these boats (I guess only the "best" tabs were reserved for Sea Ray). The stock tabs were slow at correcting things. My 2450 would have gotten up on plane faster and sooner had it had larger more responsive tabs on it. That being said, I never changed them. I did have a newer 2655 which had upgraded tabs (almost twice the surface area as the originals) and I could get up on plane at 17mph with the tabs all the way down and slow down to as low as 13-14mph if I put the tabs down far enough. The tabs were VERY responsive on that boat, to the point where you didn't want to push the buttons any longer than in one second bursts.

                              All that being said, I should throw in the usual disclaimer in that every boat is theoretically different, and much of it depends on weight distribution, # of people on board, amount of fuel/water/waste, gear etc, prop size/condition, if water is trapped anywhere in the hull, engine health etc.... Also, some people prefer to start out with the tabs all the way down to get the boat on plane sooner, and some people prefer to start out with the tabs all the way up and bring the bow down once up on plane. Much of this depends on the boat and how it handles in general. Ultimately, you have to do what works best for your own situation.

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