Water pickup drag testing

Collapse
X
 
  • Time
  • Show
Clear All
new posts
  • RandyatBBY
    Fast Electric Addict!
    • Sep 2007
    • 3915

    #61
    I have been running a telemetry receiver in one of my spec boats and a temp sensor on the motor. Starting motor temp is what ever the ambient temp is. I have seen from 61 degrees Fahrenheit to 104 F on the motor before running. The 104 was last weekend in 98 degree weather and I had just taken the boat out of the black Tahoe with windows shut. I have found that the cooling of a set up that "lives" is in the 98F to 108F, at least this is will run for years will not burning up. The big surprise to me was that the when you stop the motor will increase 20F all most immediately. I still have more testing to do and get two more receivers and temp sensors for my other spec boats. A pump system will allow running higher temps but works against the KISS method.
    Randy
    For ABS, Fiberglass, Carbon hulls and Stainless hardware
    BBY Racing

    Comment

    • kfxguy
      Fast Electric Addict!
      • Oct 2013
      • 8746

      #62
      I'm all for kiss but sometimes if you wanna succeed you gotta do a little more work. I'm not settled on what I want to do just yet but I think I'm going to try a pump with a bottom straight pickup.
      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

      Comment

      • RandyatBBY
        Fast Electric Addict!
        • Sep 2007
        • 3915

        #63
        Originally posted by kfxguy
        I'm all for kiss but sometimes if you wanna succeed you gotta do a little more work. I'm not settled on what I want to do just yet but I think I'm going to try a pump with a bottom straight pickup.
        It is just my nature to look at both sides of the coin. The pump idea is interesting and I have curiosity of the original intent of the thread.
        Randy
        For ABS, Fiberglass, Carbon hulls and Stainless hardware
        BBY Racing

        Comment

        • kfxguy
          Fast Electric Addict!
          • Oct 2013
          • 8746

          #64
          Originally posted by RandyatBBY
          It is just my nature to look at both sides of the coin. The pump idea is interesting and I have curiosity of the original intent of the thread.


          What do you mean about curiosity of the original intent of the thread? Like your curious about the results?

          I apologize that I didn't get to start the testing last weekend. I should be able to this weekend. I took the boat apart and planned on some repairs and painting it over the weekend because it was raining. I barely got the first coat of base done by Sunday evening. I had to wait till it dried because I needed to sand and touch up a few spots. Bugs got all in it. My fault for leaving the shop door open and painting it at night under a light. I put the second base coat on during the day yesterday to minimize that. I'll shoot the clear in the next day or so and then put it back together the next day. Should easily be done by Saturday. Here's the first coat for those who haven't seen it. The clear will really make it pop.



          32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

          Comment

          • RandyatBBY
            Fast Electric Addict!
            • Sep 2007
            • 3915

            #65
            WOW what paint and color is that?

            And yes I am curious about the results.
            Randy
            For ABS, Fiberglass, Carbon hulls and Stainless hardware
            BBY Racing

            Comment

            • kfxguy
              Fast Electric Addict!
              • Oct 2013
              • 8746

              #66
              Originally posted by RandyatBBY
              WOW what paint and color is that?

              And yes I am curious about the results.
              Randy that's createx pearl lime green. It has an awesome pearl effect to it. It's water based so you can wash it off if you mess up. You have to wait a day or two (I usually give it two days) before you clear it so the clear won't lift. Check this one out. In the sun. Sold this boat tho. Miss it to.


              Last edited by kfxguy; 06-07-2016, 11:23 PM.
              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

                #67
                Update. I got the boat for the first test painted and reassembled. I also got one of the pumps in today. Testing Saturday.








                This pump is very small but for its size it does very well. It is self priming too. It will shoot a stream about 5-6ft. I also timed it on three different voltages. I used 11oz of water and pumped into another cup.
                2s took 1 minute and 23 seconds
                3s took 1 minute and 6 seconds
                4s took 58 seconds. It did not run warm on 2s or 3s but did run warm on 4s. The extra 8 seconds it dropped off isn't worth it. This is a sensidyne pump btw.



                4s
                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

                  #68
                  Went did test number one. Definitely did not turn out how I expected. I can't say this is a end all for this question however. Let me say why. First is I was not in contolled laboratory conditions. I made one pass and checked speed. Then I put hatch tape starting behind the step of the middle sponson to the end of the rear sponson. I would say that pretty much eliminated the pickup drag. Also because I was having a slight amount of porpoising I moved the batts up one inch. Because it lost speed when I blocked off the pickups I ran once more with the batteries moved back to the original position. Speed was the same on this run also so I had to rule that out. All three passes were less than 1mph apart. So on to the videos. Here's video one with pickups.





                  And here's run number 2





                  Here's how I blocked them off.



                  32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                  Comment

                  • Keagan-Z06
                    Senior Member
                    • Mar 2016
                    • 970

                    #69
                    Is your receiver upside down? Nice runs!
                    Proboat Voracity-E 36" , Proboat Zelos 36 Twin , Proboat Miss Geico 29" , Traxxas Spartan, Fightercat Daytona, Zonda

                    Comment

                    • kfxguy
                      Fast Electric Addict!
                      • Oct 2013
                      • 8746

                      #70
                      Originally posted by Keagan-Z06
                      Is your receiver upside down? Nice runs!
                      No, why?
                      32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                      Comment

                      • grsboats
                        Senior Member
                        • Jul 2012
                        • 975

                        #71
                        Travis these water pick ups definitevely won't produce measured drag in your experiment but a knife blade rudder will....the speed on my SAW Jae with 4082 2000kv motor on 6S jumped from 85mph to 88mph just swaping the rudder blade.
                        Attached Files
                        GO FAST AND TURN RIGHT !
                        www.grsboats.com.br

                        Comment

                        • dmitry100
                          Fast Electric Addict!
                          • Mar 2015
                          • 1264

                          #72
                          Grsboats: Where do you get your knife blades from? They should be wedge knives though right...

                          Grsboats is right on that one, replacing rudder blades with a thin knife one can give up to 5mph increase in speed for big SAW cats.

                          Comment

                          • grsboats
                            Senior Member
                            • Jul 2012
                            • 975

                            #73
                            Dmitry you re right and this is a custom knife blade laser cut I did 3 years ago...since that only air water pick ups on my saw boats..and yes in hot set ups you will be surprised with the speed's improvement.
                            GO FAST AND TURN RIGHT !
                            www.grsboats.com.br

                            Comment

                            • srislash
                              Not there yet
                              • Mar 2011
                              • 7673

                              #74
                              Originally posted by kfxguy
                              Went did test number one. Definitely did not turn out how I expected. I can't say this is a end all for this question however. Let me say why. First is I was not in contolled laboratory conditions. I made one pass and checked speed. Then I put hatch tape starting behind the step of the middle sponson to the end of the rear sponson. I would say that pretty much eliminated the pickup drag. Also because I was having a slight amounts of
                              of porpoising I moved the batts up one inch. Because it lost speed when I blocked off the pickups I ran once more with the batteries moved back to the original position. Speed was the same on this run also so I had to rule that out. All three passes were less than 1mph apart. So on to the videos. Here's video one with pickups.





                              And here's run number 2





                              Here's how I blocked them off.



                              So anything new from a Sunday run Travis ?

                              Comment

                              • kfxguy
                                Fast Electric Addict!
                                • Oct 2013
                                • 8746

                                #75
                                Originally posted by srislash
                                So anything new from a Sunday run Travis ?
                                I didn't get to the lake today, it was raining. I did run the shocker yesterday too. First time running it on 8s since I crashed it. Ran very well even tho I had a longer rudder on it.
                                32" carbon rivercat single 4s 102mph, 27” mini Rivercat 92mph, kbb34 91mph, jessej micro cat(too fast) was

                                Comment

                                Working...