Black Pearl II Hydro - 2020

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  • ray schrauwen
    Fast Electric Addict!
    • Apr 2007
    • 9471

    #571
    Lol... I can tap the CF but not as nice as aluminum. I'll just use my nuts :)
    Nortavlag Bulc

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    • lohring
      Senior Member
      • Jun 2011
      • 182

      #572
      Consider that the latest motors in P limited hydro are RATED at 3,000 watts. That's around 4 hp. The most outrageous power claims for 7.5 cc nitro engines are less than that. The NAMBA SAW record for a sport 40 is 81 mph set in 2001. The two lap record for sport 40 is 51 seconds. The P limited SAW record is 80 mph set two years ago. The two lap record is 46 seconds. The turn fin loads should be similar.

      My sport 40 is 36" long. The P length limit is 34" Maybe it's time to rethink this to avoid running fast, hard to control little boats.

      Lohring Miller

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      • ray schrauwen
        Fast Electric Addict!
        • Apr 2007
        • 9471

        #573
        That's partly why I'm running my 34" Pearl in Limited class so that it stays completely planted.
        Nortavlag Bulc

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        • ray schrauwen
          Fast Electric Addict!
          • Apr 2007
          • 9471

          #574
          What prop can I start with on this 34" hull, Huff Leopard 3674 rewind chopped 2300kv, Castle XL2 converted esc, 6500Mah or more...?

          1814?
          Nortavlag Bulc

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          • lohring
            Senior Member
            • Jun 2011
            • 182

            #575
            I ran an ABC 1717-19-38 on my outrigger with a motor with similar KV to yours. I'll be running a TenShock with a 2680 KV in the Black Pearl so that prop may be a little big. I can fit two 5000 mah 4S batteries in parallel in it with a Castle MAMBA Monster X ESC. I'll talk to Brian Buaas to see what he thinks.

            Lohring Miller

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            • Reesor@work
              Member
              • Jul 2008
              • 53

              #576
              Originally posted by ray schrauwen
              That's partly why I'm running my 34" Pearl in Limited class so that it stays completely planted.
              Trust me - you can and will blow that hull off in P Limited. That's huge Kv in that hull for P Limited. I'd start 'small' with props and work your way up - each iteration and prop type will require some trimming. Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast. I can't believe the props the Michigan guys run in P Limited racing. Lohring is correct - these little motors generate crazy power.
              Reesor Boat Works

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              • TRUCKPULL
                Fast Electric Addict!
                • Apr 2007
                • 2971

                #577
                Originally posted by lohring
                Consider that the latest motors in P limited hydro are RATED at 3,000 watts. That's around 4 hp. The most outrageous power claims for 7.5 cc nitro engines are less than that. The NAMBA SAW record for a sport 40 is 81 mph set in 2001. The two lap record for sport 40 is 51 seconds. The P limited SAW record is 80 mph set two years ago. The two lap record is 46 seconds. The turn fin loads should be similar.

                My sport 40 is 36" long. The P length limit is 34" Maybe it's time to rethink this to avoid running fast, hard to control little boats.

                Lohring Miller
                3000 W = over 4 HP

                Larry
                Past NAMBA- P Mono -1 Mile Race Record holder
                Past NAMBA- P Sport -1 Mile Race Record holder
                Bump & Grind Racing Props -We Like Em Smooth & Wet

                Comment

                • lohring
                  Senior Member
                  • Jun 2011
                  • 182

                  #578
                  Originally posted by TRUCKPULL
                  3000 W = over 4 HP

                  Larry
                  OK it's 4.023066267 hp(I) or 4.078864852 hp(M)

                  Sounds like 4 hp is pretty close.

                  Lohring Miller

                  Comment

                  • ray schrauwen
                    Fast Electric Addict!
                    • Apr 2007
                    • 9471

                    #579
                    Originally posted by Reesor@work
                    Trust me - you can and will blow that hull off in P Limited. That's huge Kv in that hull for P Limited. I'd start 'small' with props and work your way up - each iteration and prop type will require some trimming. Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast. I can't believe the props the Michigan guys run in P Limited racing. Lohring is correct - these little motors generate crazy power.
                    Thanks Steve. I hope you're doing well.
                    Nortavlag Bulc

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                    • ray schrauwen
                      Fast Electric Addict!
                      • Apr 2007
                      • 9471

                      #580
                      Originally posted by lohring
                      I ran an ABC 1717-19-38 on my outrigger with a motor with similar KV to yours. I'll be running a TenShock with a 2680 KV in the Black Pearl so that prop may be a little big. I can fit two 5000 mah 4S batteries in parallel in it with a Castle MAMBA Monster X ESC. I'll talk to Brian Buaas to see what he thinks.

                      Lohring Miller
                      Thanks Lohring!
                      Nortavlag Bulc

                      Comment

                      • T.S.Davis
                        Fast Electric Addict!
                        • Oct 2009
                        • 6221

                        #581
                        Originally posted by Reesor@work
                        Terry would be the guy to ask regarding a starting point with that Kv. His Pearls are glued to the water and run obscenely fast.
                        My Pearl most certainly is not glued to the water. haha.

                        I'm super hesitant to recommend props without seeing a boat run myself. If I recommend what I really think will work and it bakes a motor........well that sucks.

                        Best to start small Ray. I think Don runs 17 series props on that motor. I would start around 1814-17-45 maybe. Do the heat check deal every 2 or 3 laps. Remember too that you may/might/maybe need to make strut adjustments for diameter and even rake. An 1814-17-45 vs an 1814-19-38 might need an adjustment. Tiny tiny adjustments are the difference between flight and fast on these. Like .5mm at a time. This is true of all the Pearls in my experience.
                        Noisy person

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                        • ray schrauwen
                          Fast Electric Addict!
                          • Apr 2007
                          • 9471

                          #582
                          Thanks. I have a 1615 I can try first and some proboat 1716 SS props.
                          Nortavlag Bulc

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                          • T.S.Davis
                            Fast Electric Addict!
                            • Oct 2009
                            • 6221

                            #583
                            The 16 likely wont plane.
                            Noisy person

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                            • ray schrauwen
                              Fast Electric Addict!
                              • Apr 2007
                              • 9471

                              #584
                              LOL... thx again.
                              Nortavlag Bulc

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                              • lohring
                                Senior Member
                                • Jun 2011
                                • 182

                                #585
                                Brian thinks an ABC 1715 is good for my Black Pearl with the TenShock motor. We'll see.

                                Lohring Miller

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