Is this fast for 4s?

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  • kfxguy
    Fast Electric Addict!
    • Oct 2013
    • 8746
    #1

    Is this fast for 4s?

    A few of you may have seen the little 32" cat I'm playing with right now. I mane some incredible 3s passes today (81.1mph) and decided to bump it up to 4s. Been messin around with some different abc props. Just trying to see what it likes. I've got a few more things to try. One thing is when I finally threw my fastest prop on the batts were down a little AND I only had a pair of tiny 3100mah batts in it. They don't have the power the 5800's I usually run have. Nevertheless I still think this is pretty quick for my 3rd time running it. What do you guys think? (32" Rivercat, single motor, weighs 8.3lbs ready to go, 9.2lbs with the 5800 batts


    Voltage before putting in the water




    And the result. Nice smooth clean pass and I can get on it pretty quickly without it coming up.



    32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was
    Tags: None
    • kfxguy
      Fast Electric Addict!
      • Oct 2013
      • 8746
      #2
      O and I wanna add, I'm doing all these props myself. Ha! Lol
      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

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        • longballlumber
          Fast Electric Addict!
          • Apr 2007
          • 3132
          #3
          How long are your passes? At the timed events it's not "top speed" in the the traps; it's the time to cover 330ft two ways (average)....

          In response to your question.... It's relitive!

            Comment

            • kfxguy
              Fast Electric Addict!
              • Oct 2013
              • 8746
              #4
              Originally posted by longballlumber
              How long are your passes? At the timed events it's not "top speed" in the the traps; it's the time to cover 330ft two ways (average)....

              In response to your question.... It's relitive!

              Well in testing my passes are probably 500-600ft but I'm only doing that to make sure I get a accurate gps reading. It updates once a second. It accelerates very quickly without the nose coming up. With all the reading and videos I've watched, I feel like I can get it to top speed before I hit the timing beam or shortly after it. Even in full kill mode, the boat is extremely controllable. I got tired of jacking around with it that I went back in my notes and balanced the boat like my original one. I know it worked and I know it was stable. That boat saw 97.5 but with the knowledge I have now and stuff I have at my disposal, I could have surpassed that at this point. Obviously because I'm doing the same thing on 4s I was before on 7s with not much more kv than I originally had! I've just been making efforts to make things more efficient and it's paid off. If weather is good enough tomorrow I'm gonna hit the lake with a full charge and higher capacity (more amps under load too) batteries. Should be interesting.
              32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                Comment

                • Buddyroe
                  Junior Member
                  • Dec 2014
                  • 28
                  #5
                  I'm impressed. Good job keeping it in the water!

                    Comment

                    • kfxguy
                      Fast Electric Addict!
                      • Oct 2013
                      • 8746
                      #6
                      Originally posted by Buddyroe
                      I'm impressed. Good job keeping it in the water!
                      Thanks! I've got things settled a good bit better than last weekend. For some reason the boat likes a little negative in the strut, otherwise it starts to get flighty over 80mph. It actually came up on me last weekend and I was quick enough to let off. Now I can nail the throttle and she stays settled.


                      Also I pulled my logs. On 3s it pulled a max (burst) of 276 amps. Temp was a max of 138f. Oddly on 4s things got cooler and amps got lower without propping back down. Temps were 113f max and amps were 260ish max (burst) and leveled off below 200 to about 180ish. Guess I can go up on prop still.....
                      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
                          #7
                          Originally posted by longballlumber
                          How long are your passes? At the timed events it's not "top speed" in the the traps; it's the time to cover 330ft two ways (average)....

                          In response to your question.... It's relitive!

                          What do you mean it's relative?
                          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                            Comment

                            • pistol18
                              Senior Member
                              • Sep 2012
                              • 248
                              #8
                              Great results Travis, always enjoy watching and reading about your builds, testing and results! Thanks for sharing, it helps people like me learn and try things on our boats.

                                Comment

                                • kfxguy
                                  Fast Electric Addict!
                                  • Oct 2013
                                  • 8746
                                  #9
                                  Originally posted by pistol18
                                  Great results Travis, always enjoy watching and reading about your builds, testing and results! Thanks for sharing, it helps people like me learn and try things on our boats.

                                  O man, that boat in your avatar is my all time favorite! I remember drooling over that thing when I first got into boating. I contacted the guy who painted it and it was way out of my budget lol. Love it! Anyway, thanks for the compliment, sometimes I get discouraged when I post stuff like this and no one posts back or says anything about it. It's comments like these that keep me still doing it...as cheesy as it may sound....no one likes talking to themselves! Lol
                                  32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

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                                    • srislash
                                      Not there yet
                                      • Mar 2011
                                      • 7673
                                      #10
                                      Good going Travis. I would expect to find the amps lower on higher cells unless you were over propped. X amount of watts to turn that prop, watts divided by volts =amps. Or this has been my findings.

                                        Comment

                                        • kfxguy
                                          Fast Electric Addict!
                                          • Oct 2013
                                          • 8746
                                          #11
                                          Originally posted by srislash
                                          Good going Travis. I would expect to find the amps lower on higher cells unless you were over propped. X amount of watts to turn that prop, watts divided by volts =amps. Or this has been my findings.
                                          Thanks! At this point I think I'm still well under what the motor and esc can take. I do have a couple more little things to try. Think I can go a tad shorter with the rudder. I'm gonna take it down in 1/8" increments. I heard 1/4" is worth 1 mph typically. While I can't remove an inch from it, everything counts. I think the higher mah cells will definitely help. Won't know till I try it, but like the wires and cap bank, it's all a learning experience!
                                          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                                            Comment

                                            • longballlumber
                                              Fast Electric Addict!
                                              • Apr 2007
                                              • 3132
                                              #12
                                              Originally posted by kfxguy
                                              What do you mean it's relative?
                                              I am not trying to discount your achievement. I was only trying to point out the numbers in the record books for IMPBA and NAMBA is a time/distance calculation. When using a GPS it's a single data point (peak) during a particular run that is ONLY a one way pass... IMO they are completely different methods of answering your original question... "Is this fast for 4S?"

                                              Later

                                                Comment

                                                • kfxguy
                                                  Fast Electric Addict!
                                                  • Oct 2013
                                                  • 8746
                                                  #13
                                                  Originally posted by longballlumber
                                                  I am not trying to discount your achievement. I was only trying to point out the numbers in the record books for IMPBA and NAMBA is a time/distance calculation. When using a GPS it's a single data point (peak) during a particular run that is ONLY a one way pass... IMO they are completely different methods of answering your original question... "Is this fast for 4S?"

                                                  Later
                                                  I'm aware. I'm not trying to discount any records either. I am excited that it did go this fast tho. Running it through the traps is another level that ill hopefully experience soon enough. I would be quite foolish not to have my stuff together not knowing how fast it is before I attempt it though, don't you think? The gps is a tuning tool. It lets me know the potential speed I can achieve at an event if conditions are favorable, I can keep ur in the water, accelerate fast enough and keep my line between the two points as straight as possible. This I know. But do know, I get annoyed when people say the gps isn't accurate (not saying you've said that) because it is. And I know that chances of me running the exact same speed through the traps is slim to none, but the boat is capable of a 95mph speeds, all out. But like I said, the gps is being used as a tuning tool. How could I possibly know my speeds, progress and the difference in my prop changes without it? You can't "see" a 3mph difference, I shortened wires and made a new cap bank, went I ran it, it looked the same to me but having the gps let me know my efforts paid off by 3mph. I'm just trying to prepare the boat and myself if I ever do get the pleasure of attending an event. Know what I mean?
                                                  32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                                                    Comment

                                                    • Buddyroe
                                                      Junior Member
                                                      • Dec 2014
                                                      • 28
                                                      #14
                                                      We have had the same issues with this in our boat racing world. Boats we drive with high performance outboards. They have records through speed traps that have been beat on a GPS that read in 1/10's. Doesn't count but it's cool to do for bragging. We enjoy doing just that for fun. Again good job! Negative trim and don't let it run out of power to keep the nose down.

                                                        Comment

                                                        • kfxguy
                                                          Fast Electric Addict!
                                                          • Oct 2013
                                                          • 8746
                                                          #15
                                                          Originally posted by Buddyroe
                                                          We have had the same issues with this in our boat racing world. Boats we drive with high performance outboards. They have records through speed traps that have been beat on a GPS that read in 1/10's. Doesn't count but it's cool to do for bragging. We enjoy doing just that for fun. Again good job! Negative trim and don't let it run out of power to keep the nose down.

                                                          Thx! I think I got her trimmed where I want. Barely any negative, but there is some. Level strut, it won't stay on the water. I've always been against negative angle on the prop, but I'm having to overcome that. It's what this boat likes and it's not slowing it down any. I'll concentrate on maximizing efficiency and cutting drag now. I should get to the lake later on today and post some higher speeds from the changes I'm making (small but meaningful) and I hope I can coax one of my kids to be a fool like me and go in the cold and video for me lol
                                                          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

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