P-Limited Motors - Im going to jump on the hot seat.

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

    #256
    IDK about the batteries. It doesn't matter how many mah I carry (at the moment) because any more amps and fr'shizzle. I carry 10k for offshore just to combat the rough water. I don't need the power. Ty carries 8k in the Thomas but we've added no other weight to the boat. We can run twice on a charge.

    I don't know if that will still be the case with the new potential motors. If the new gear is tougher guys might push harder/more amps. I don't have enough experience with the others to have a clue.

    I have to remind myself that it's a 2017 (potential) start up. That's forever from now. By then we may not be buying AQ motors. Nobody really knows. They may be perfectly content to continue down their current path.

    I have on my kitchen table:

    SSS 3660 1950kv decent motor
    SSS 3660 1780kv never been run

    The 1950 I ran in a paper light Whiplash. I was able to hang with the big P dogs but I'm not sure if that was because I was fast or if it was a combination of the boat being under 5 pounds and me bludgeoning my way in. I was going to hang back and see how it went but found myself in the mix at the start and just stayed in the lanes making guys go the long way. Felt like LSH speeds.
    Noisy person

    Comment

    • Quietlee
      Senior Member
      • Jan 2008
      • 162

      #257
      I feel that capacity is self limiting through a couple of reasons. Weight is the one that really stands out to everyone. The other issue is that you are only going to be able to push so much through a motor before pushing it too much. You only need so many MAH in the boat to complete a heat. Extra capacity is needed to give a little headroom for the battery life, but anything over that just gets turned into heat which damages your components.
      As far as the ESC issue concerning timing, the RTR versions that have been used will probably go away as the manufacturers "upgrade" their RTR versions anyway.

      Comment

      • longballlumber
        Fast Electric Addict!
        • Apr 2007
        • 3132

        #258
        I am still very interested in hearing the thoughts regarding the compatibility back to the RTR speedo’s. This would be an impact for the immediate future; probably not so much for the long term future. The discussion seems to be going in a direction in which we are/will be breaking ties with current and future RTR power systems. If that IS the case, we are getting very close to an “Almost (but not quite) P” class.

        COST – has been wrangled in a bit with the new list. Some would argue that $60 (w/jacket)-$115 (no jacket) is a pretty big swing.

        Balance in performance – Strictly speaking from the recently added motors; only time will tell. I still have a strong feeling a small percentage will be the superior motors. The $60 or the $115; who knows.

        Disclaimer: I REALLY don’t care either way. Personally, I am going to buy whatever I think will allow me to be as competitive as possible. I am interested in making sure we are able to promote the hobby by increasing participation across BOTH orgs.

        I am still looking to establish the INTENT of the class though.

        Comment

        • Darin Jordan
          Fast Electric Addict!
          • Apr 2007
          • 8335

          #259
          Originally posted by longballlumber
          I am still looking to establish the INTENT of the class though.
          It sounds like we need to start another thread to help define this...
          Darin E. Jordan - Renton, WA
          "Self-proclaimed skill-less leader in the hobby."

          Comment

          • LuckyDuc
            Team Ducati Racing
            • Dec 2008
            • 989

            #260
            Originally posted by longballlumber
            I am still very interested in hearing the thoughts regarding the compatibility back to the RTR speedo’s. This would be an impact for the immediate future; probably not so much for the long term future. The discussion seems to be going in a direction in which we are/will be breaking ties with current and future RTR power systems. If that IS the case, we are getting very close to an “Almost (but not quite) P” class.

            I am still looking to establish the INTENT of the class though.
            I'm sure that the RTR ESCs will work, but because you cannot adjust the AQ ESC's timing, it will not be running optimally with a motor that wants less timing e.g. D wind motors.

            Regarding INTENT... You'll probably get as many answers as there are motor suggestions in this thread. Limited means so many different things to so many people. To me, it means...
            -Limited speed (upper 40's to low 50 mph depending on hull type and conditions.)
            -Less carnage in racing heats
            -Less boat recovery after heats.
            -Less damage to the boats when accidents do happen
            -A plethora of existing information on proven setups for those just starting out (Let's call it direction on where to start).
            -More focus on things like building techniques, setup, prop work, and driving skills as opposed to buying instant horsepower to compensate for a lack there of.

            Comment

            • Doby
              KANADA RULES!
              • Apr 2007
              • 7280

              #261
              The true intent of any class is to get participation.
              Grand River Marine Modellers
              https://www.facebook.com/search/top/...ne%20modellers

              Comment

              • Darin Jordan
                Fast Electric Addict!
                • Apr 2007
                • 8335

                #262
                It seems like the one sticking point in regards to "intent" is the tie to RTRs. We generally seem to agree on most of the other bits.

                Did we put the original rules in place to specifically be able to run RTRs, or, by adopting their power systems, was that just an ancillary side-benefit? It really didn't take long for people to migrate to all sorts of aftermarket hulls.
                Darin E. Jordan - Renton, WA
                "Self-proclaimed skill-less leader in the hobby."

                Comment

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

                  #263
                  John hit the nail on the head.

                  Back in the day........when Dave put it together we were trying to encompass what had proven successful in various locations. So what did "successful" mean?

                  A class with boats racing is success. A class without boats is failure. It's really that simple.

                  Why was it successful? Subject to debate (again) but we thought at the time it was:

                  Ease of entry (rtr's)
                  Fast enough to get the fizz (for the vets)
                  Cost effective (bang for the buck)

                  All that said, is it possible to continue with that given that one of those factors may well be short lived. Feels like (no guarantee of course) that the rtr "ease of entry" piece of that puzzle is fading away.

                  It may be that the next phase needs a different focus entirely. Is fast enough and cost effective enough to sustain it? I don't know.
                  Noisy person

                  Comment

                  • Darin Jordan
                    Fast Electric Addict!
                    • Apr 2007
                    • 8335

                    #264
                    Originally posted by T.S.Davis
                    Feels like (no guarantee of course) that the rtr "ease of entry" piece of that puzzle is fading away.
                    Just some food for thought on the RTR... Let's say we weren't even talking about this...

                    As the CD of the event, one would have the ability to "approve" a new RTR into the class, based on 28.D.1.d.iii)(b).
                    (b) Any generational change of an approved motor, or a motor that
                    is used in a Ready To Run (RTR) offering from a manufacturer
                    that produces over 100 units of said offering,
                    as long as there is
                    no more than a 5% increase in any of the following
                    manufacturers specifications as compared to any single
                    approved motor: Kv, maximum constant amperage rating,
                    mass, and MSRP.

                    Clearly, however, there was NEVER the intent to allow the available power to increase more the "5%" "compared to any single pproved motor: Kv, maximum constant amperage rating, mass, and MSRP."

                    This rule excludes the BJ29 V3 (36 x 61mm 2000KV... 61mm is slightly more the 5%) and the new IM31 V3 (40mm x 68mm... almost 400g... way over 5%), so two of the popular RTRs that started this craze wouldn't fit anyhow.

                    Further, does this "5%" rule not show a desire to limit the motor size to be close to what we have now? It's clear that the intent wasn't ever to allow a 40mm x 68mm motor.

                    This shows an intent to limit the motor size and overall performance, more than an intent to be adaptable to ANY RTR package that might come about.
                    Darin E. Jordan - Renton, WA
                    "Self-proclaimed skill-less leader in the hobby."

                    Comment

                    • NativePaul
                      Greased Weasel
                      • Feb 2008
                      • 2761

                      #265
                      Originally posted by longballlumber
                      Another thought, I haven’t heard any ideas on limiting battery mAh? While capacity is difficult to tech; what about size and weight? It’s my understanding this restriction is being used successfully over the pond; right?
                      Half right Mike, I race with Naviga and we don't use our motors as fuses, all our classes are open motor classes. We do use LiPo weight to limit power, our Mono2 and Hydro2 classes have similar power to a very safe P ltd boat from what I can tell.

                      Those classes have a maximum battery weight of 560g (including wire, shrink wrap, velcro, connectors,etc) to play with our races are 6 minutes +10 second mill, +in lap, but if we ignore the mill and in lap it makes the maths very easy as 6 minutes is 1/10th of an hour so the absolute maximum amp draw we can pull is 10 times our battery capacity, which has lead to an evolution of batteries offering better energy density at the cost of power density, ie packs with high capacity but low "C" rate, most of my packs are 20C and I disbelieve the few I have that are labeled as 30C, None have PCBs, all have leads an inch long or less, some with connectors soldered straight onto tabs, only about half have heat shrink (some just use kapton tape for insulation where it is needed) and those that do it is pretty flimsy stuff compared to normal, none have velcro we have to make the boats hold the batteries.

                      All these things limit the amount of LiPos that are suitable for us. We allow 4-6s but with the same battery weight the power is the same and it is pretty irrelevant, so I will just talk about 4s here ETTI have 20C 6600mAh, Turnigy A specs have 6600mAh with 65C label but cells are exactly same size, weight and performance as ETTI 20C, Tenshock 30C 6800mAh and Redzone 30C 6800mAh, which is more than likely only 2 different cells giving a maximum of 68Amps average current.

                      Of course to get the full 66-68A available you would have to FLATTEN your battery not leave 20% in it for longevity, I don't think many leave 20% in our cells, but if you flattened them completely you would be lucky to get a race meeting out of them and I don't think many have pockets that deep maybe, a few for big races. Personally I leave 5-9% which gets normally gets me 2 seasons out of a set of cells and in that time there are probably going to be better cells that I want anyway.

                      From what I hear, you guys are running from about 70-90A in P ltd, and it sounds the same in that if you stay near 70A you can get years from the motor but if you push it to 90A you can expect a much shorter life.

                      You only need one way to limit power, as you already use the motor you don't need batteries too, it isn't a better a solution, it just means it is a different thing failing (puffed LiPos are less smelly than burned motors, and don't take ESCs with them so may be cheaper, but are more scary). I wouldn't say it is any more successful than what you are doing.

                      The fairest, safest, and cheapest in the long run way to limit power is with electronic power limters like the flyboys use, but we voted it down, who wants to spend $100 adding something which slows you down? Very few of us when we were first adding LiPos to the rules, but after years of buying new cells probably most of us.
                      Paul Upton-Taylor, Greased Weasel Racing.

                      Comment

                      • TheShaughnessy
                        Fast Electric Addict!
                        • Mar 2011
                        • 1431

                        #266
                        I am regretfully making a post here. I have to side with the direction Darin is headed and agree with his reason for doing so, can length/dimensions and weight are easily verifiably. I do not feel like the cost is a huge issue, putting a cap is fine though. Interestingly batteries were brought up.
                        Here is a scenario, two identical boats, one with 5000 mah 60 c batteries (4s) the other with 5000 mah 35 c (also 4s). The boat with batteries more capable of delivering power is going to be faster, anywhere from 1-3 mph possibly more. This goes back to cost, the 60 c cells will typically be associated with a higher cost, so if the cost of batteries isn't hugely significant than why should the cost variation of the motors be an issue. Correct me if I'm wrong here but these are boats (bust out another thousand). We are on a scale level so lets scale that to bust out another hundred. Racing is a luxury not a necessity, if you can't afford it you can't afford it, no shame there.
                        Another scenario, lets say a motor makes it onto the "list" and it proves itself to be capable of making a p LTD cat do 57 mph (arbitrary number I made up), that is 10 mph faster than my fastest p ltd cat runs and 5-7 mph faster than razer's (Ray) cat (that thing is fast!!). In a vacuum the faster motor would win every time, but we don't race in a vacuum. I can't tell you how many times I've beat out faster boats because they were upside down, so why does it matter if another motor makes some other guys boat faster, he would likely be faster than you running the exact same motor as is the case already. I believe the goal is to have similar speeds, not exactly the same. Under the current rules we already have some racers in the low 40's and some in the low 50's, at least over here in D19 so again, what's the big deal if the "motor" makes the boat faster. I feel there are so many other variables involved with mph gains that the motor isn't going to be the deciding factor, given it falls within the specs Darin has outlined.

                        Lastly this is a drivers class if your boat is faster than mine but I stay in lane 1 and you are out in lane 5 guess who is going to win, the guy racing the shorter course. Lets say you don't nail the start, cut a buoy, etc. You are going to struggle to win the heat regardless of motor selection.

                        Im not sure I've actually said anything here so I'm about done. I personally have no issues with the current rule set, haven't burnt a motor in 2 seasons and have 4 spares I bought in anticipation of burning some. I finished 2nd in our club (SCSTA) racing last year (not district) and I'm sitting in 2nd for the 2015 race season I don't say this to impress you but to impress upon you that you don't have to be the fastest to be competitive. You do however need to time the start properly, stay in lane one or close to it, and last but certainly not least FINISH heats.

                        All that being said I'd vote in a new selection of motors, continue to race the ones off the old list and likely experience similar results.

                        Comment

                        • NativePaul
                          Greased Weasel
                          • Feb 2008
                          • 2761

                          #267
                          If there is power parity the fast guys must be running looser in order to be fast. Running on the edge should always be a gamble, so sometimes they win, sometimes they don't finish. If there is not power parity those with more power can run both fast and safely wet.
                          Paul Upton-Taylor, Greased Weasel Racing.

                          Comment

                          • JimClark
                            Fast Electric Addict!
                            • Apr 2007
                            • 5907

                            #268
                            And really know how the art of prop tweaking

                            Originally posted by NativePaul
                            If there is power parity the fast guys must be running looser in order to be fast. Running on the edge should always be a gamble, so sometimes they win, sometimes they don't finish. If there is not power parity those with more power can run both fast and safely wet.
                            "Our society strives to avoid any possibility of offending anyone except God.
                            Billy Graham

                            Comment

                            • Darin Jordan
                              Fast Electric Addict!
                              • Apr 2007
                              • 8335

                              #269
                              Guys... quick question:

                              In the rules, there is an allowance for the CD to allow additional motors.

                              IF we were to go with the defined list of motors, as I posted above, would we still retain this section? Seems to add ambiguity and, with the larger selection of motors, unnecessary??

                              For reference:
                              iii) In addition, the CD has the discretion to allow the following:
                              (a) An aftermarket motor that is a re-labeled and exact copy of any
                              approved motor.

                              (b) Any generational change of an approved motor, or a motor that
                              is used in a Ready To Run (RTR) offering from a manufacturer
                              that produces over 100 units of said offering, as long as there is
                              no more than a 5% increase in any of the following
                              manufacturers specifications as compared to any single
                              approved motor: Kv, maximum constant amperage rating,
                              mass, and MSRP.

                              (c) The race flyer shall list additional allowed motors for the event
                              Darin E. Jordan - Renton, WA
                              "Self-proclaimed skill-less leader in the hobby."

                              Comment

                              • D. Newland
                                Fast Electric Addict!
                                • Dec 2007
                                • 1030

                                #270
                                I'd ditch it. As Terry has mentioned, we were just trying to save time from the lengthy rule proposal process with that wording, in the event a "no-brainer" motor came out that matched those specs.

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