How do these motors compare power wise?

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  • kfxguy
    Fast Electric Addict!
    • Oct 2013
    • 8746

    #1

    How do these motors compare power wise?

    I'm on the fence on which motor I want to get. Long story short, lehner 2250 1972kv on 6s ran 96mph on 6s in my 32" cat. I'm building another one but this time I'm not using a lehner. More of a budget build I guess you could say. Everything thing else being the same (Esc, prop etc) I was hoping to get close to what the lehner was doing. I was considering a tp power 4060 2040kv, going a little higher kv because the lehner rates theirs a little different, with a load on it. How much load? I'm not sure but I've read that the unloaded kv is 10% higher which would be roughly 2169kv. The tp would be "close enough" if I'm thinking right. Also my thought process is maybe the 4 pole may be able to keep up with the 2 pole because the rpm realm is mid to low 40k's. I would think the lehner would grossly outshine it at a higher rpm, but that's just my theory based on the limited experience I've had with them. I'd rather get a neu but they don't offer a kv that will suit my intended use. If I get a custom wind, by the time I pay for that I might as well order another lehner. So what are you guys thoughts? Would the tp keep up with it close enough or am I wasting my time? I've only run one tp motor and it did pretty well. Think it's worth a shot?
    32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
  • NativePaul
    Greased Weasel
    • Feb 2008
    • 2760

    #2
    Lehners rate their KV at the point of maximum efficiency, which with your 2250/6 on 6s is 94.5% at 187A.

    While I have never used one or heard about anyone testing their efficiency, I would doubt the TP is close to Lehner in that regard, If the TP was 85% efficient which would be OK for a mid range budget motor, to get the same RPM at the prop as the Lehner you would need 2320kv, it would consume 12% more amps and produce 3 times more heat.

    If all you are interested in is speed and you weren't pushing the Lehner to its limits then a TP could be just as fast, but losing that much more energy to heat it will reach its failure point a lot quicker, you could use a motor with more mass than the Lehner's 560g to slow the heat rise rate down and the bigger can would have more surface area to dissipate a bit more heat.
    Paul Upton-Taylor, Greased Weasel Racing.

    Comment

    • kfxguy
      Fast Electric Addict!
      • Oct 2013
      • 8746

      #3
      Originally posted by NativePaul
      Lehners rate their KV at the point of maximum efficiency, which with your 2250/6 on 6s is 94.5% at 187A.

      While I have never used one or heard about anyone testing their efficiency, I would doubt the TP is close to Lehner in that regard, If the TP was 85% efficient which would be OK for a mid range budget motor, to get the same RPM at the prop as the Lehner you would need 2320kv, it would consume 12% more amps and produce 3 times more heat.

      If all you are interested in is speed and you weren't pushing the Lehner to its limits then a TP could be just as fast, but losing that much more energy to heat it will reach its failure point a lot quicker, you could use a motor with more mass than the Lehner's 560g to slow the heat rise rate down and the bigger can would have more surface area to dissipate a bit more heat.
      Good info. Supposedly the tp are rated at 90% efficiency. How true that is, I don't know. Now. The neu's are rated at 90% too iirc. I have ran this motor and a neu 1521 in the same hull with the same prop and they were almost exactly the same speed. The neu kv was 1860 and the tp was 1870kv. Then I have another thought in the back of my head....my mono, 91mph with a lehner 2260 and 84.7mph (batts were run down too) with a neu 1527. Lehner kv 1677 and neu 1500kv. Both on the same batts. The props were different but the lehner could not turn the prop like the 1527 could. So. Just some thoughts. One is definitely a fair comparison, the other one is hard to say, but still worth considering and mentioning. I sound like I'm trying to talk myself into trying a tp don't I? Lol. I guess I could always sell it if it don't work out.
      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

      Comment

      • NativePaul
        Greased Weasel
        • Feb 2008
        • 2760

        #4
        IF it was 90% the figures would be 2190kv, 5% more amps, 85% more heat.
        Paul Upton-Taylor, Greased Weasel Racing.

        Comment

        • TRUCKPULL
          Fast Electric Addict!
          • Apr 2007
          • 2969

          #5
          Travis

          What about the NEU 1527 1D 2300KV 8mm shaft
          It would give you a little more RPM
          You could use a little smaller Dia. prop for more stability, or same prop for more speed.

          This motor on 6S has been used for SAW runs many times.

          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

          • kfxguy
            Fast Electric Addict!
            • Oct 2013
            • 8746

            #6
            Originally posted by TRUCKPULL
            Travis

            What about the NEU 1527 1D 2300KV 8mm shaft
            It would give you a little more RPM
            You could use a little smaller Dia. prop for more stability, or same prop for more speed.

            This motor on 6S has been used for SAW runs many times.

            Larry
            Problem is the length. Maybe I need to mock up a hull and see how it turns out. 2300kv on 6s is a little higher than I like tho. 6s and 2200 is kind of my ceiling but that's not that much difference. 48,840rpm vs 51,060
            32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

            Comment

            • TRUCKPULL
              Fast Electric Addict!
              • Apr 2007
              • 2969

              #7
              Originally posted by kfxguy
              Problem is the length. Maybe I need to mock up a hull and see how it turns out. 2300kv on 6s is a little higher than I like tho. 6s and 2200 is kind of my ceiling but that's not that much difference. 48,840rpm vs 51,060
              50,000 prop RPM is about right for SAW's is it not???

              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

              • kfxguy
                Fast Electric Addict!
                • Oct 2013
                • 8746

                #8
                So let's do this.... How does a 1527 vs a 4070 tp compare? Both same length and diameter....2200kv tp and 2300kv neu.... The neu is double the price too. I have a 4060 that I just took apart and it's nicely made....very close to a neu...
                32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                Comment

                • srislash
                  Not there yet
                  • Mar 2011
                  • 7673

                  #9
                  Do it Trav, as you know I have been running TP's for quite awhile now. How many runs on that pair of 12s 4050's all loaded up for 100mph and 43,000rpm? Quite a number and still going strong.
                  You have me double thinking my HPR build with the LMT's. It seems to me the LMT's are away more sensitive to radical prop change. I could go from my 47mm props to 50mm and the TP's would pull them. Faster? Who knows but how about that jump with LMT?

                  Comment

                  • srislash
                    Not there yet
                    • Mar 2011
                    • 7673

                    #10
                    And since the numbers are up, the motors are 1020kv, batts are Dinogy 12s 3300mah and the real shaft rpm is 42,500'ish. At some point I had batts under load at 3.65 volts per cell.

                    Comment

                    • kfxguy
                      Fast Electric Addict!
                      • Oct 2013
                      • 8746

                      #11
                      Originally posted by srislash
                      Do it Trav, as you know I have been running TP's for quite awhile now. How many runs on that pair of 12s 4050's all loaded up for 100mph and 43,000rpm? Quite a number and still going strong.
                      You have me double thinking my HPR build with the LMT's. It seems to me the LMT's are away more sensitive to radical prop change. I could go from my 47mm props to 50mm and the TP's would pull them. Faster? Who knows but how about that jump with LMT?
                      Lmt's are VERY sensitive to prop change an voltage. In my limited experience with them I've found:

                      If you go up on voltage (at a certain point) the boat doesn't go much faster unless you go down in prop. I had that happen in both boats. With the neu in both boats when you add voltage it picks up a lot per cell. It would pick up 17mph in my Rivercat going from 6s to 7s
                      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                      Comment

                      • TRUCKPULL
                        Fast Electric Addict!
                        • Apr 2007
                        • 2969

                        #12
                        If you go with the TP or maybe even the NEU to be pushing the 50,000 RPM mark
                        you may want to look at the Boca Ceramic Hybrid bearings from OSE

                        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

                        • kfxguy
                          Fast Electric Addict!
                          • Oct 2013
                          • 8746

                          #13
                          Originally posted by srislash
                          And since the numbers are up, the motors are 1020kv, batts are Dinogy 12s 3300mah and the real shaft rpm is 42,500'ish. At some point I had batts under load at 3.65 volts per cell.
                          What do you think....

                          4060 2040kv or
                          4070 2050kv or
                          4070 2200kv? I do like that the 4070 has an 8mm shaft but at 100mm long it's gonna be hard to fit that in a 32" cat...it's doable tho. Just not sure if the slight power difference is worth it.
                          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                          Comment

                          • kfxguy
                            Fast Electric Addict!
                            • Oct 2013
                            • 8746

                            #14
                            Originally posted by TRUCKPULL
                            If you go with the TP or maybe even the NEU to be pushing the 50,000 RPM mark
                            you may want to look at the Boca Ceramic Hybrid bearings from OSE

                            Larry

                            Thx. I usually do change my bearings to ceramic. Didn't on the lehner because I don't have tool to take them apart.
                            32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                            Comment

                            • TRUCKPULL
                              Fast Electric Addict!
                              • Apr 2007
                              • 2969

                              #15
                              TP 4070 2200KV is a 2Y
                              TP 4070 2050KV is a 4D

                              Y winds are normally less AMP's
                              D winds are AMP hogs with lots of torque.

                              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

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