Page 4 of 5 FirstFirst ... 2345 LastLast
Results 121 to 160 of 162
  1. #121
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by fastmachine View Post
    How many amps are required for this motor on 3S and 4S? With gearing set for 80+ mph.

    Boost 3S (Parallel) 1800mah 45c, 162 amps
    Boost 2S (Series) 2450mah 50c, 122.5 amps
    ******* 2S (Series) 2250mah 65c, 146.2 amps
    That depends more of the length of the road you have than the amps. Most amps are used for accelleration, not to get to a top speed of 80mph. 100A on 3S is more than enough if you have room enough.
    Nobody is born with experience

  2. #122
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Did some more speed runs this weekend. This motor is blistering fast on 2S and 3S, but 4S isn't going to work. The truck is faster on 3S (70 mph) than 4S. The 2S in series just isn't enough amps for this motor. You would need to cutout the battery trays and make a custom battery mount to be able to run 4S batteries in parallel.

    Here it is in kill mode. I added a wheel weight to the front bumper which helps out big time to keep the front end down. The drivetrain has been rock solid after many runs.


  3. #123
    RC Champion
    Join Date
    Nov 2010
    Location
    Lilydale, Victoria, Australia
    Posts
    2,843
    Did you try lowering the gearing and then running 4s ?

    4s geared for the same speed as 3s will only require 75% of the amps

    Cheers
    Slash Platinum
    Xerun 150 / Tenshock SC401 3500kv

  4. #124
    RC Racer
    Join Date
    Apr 2011
    Location
    USA
    Posts
    159
    Quote Originally Posted by crusey View Post
    Did you try lowering the gearing and then running 4s ?

    4s geared for the same speed as 3s will only require 75% of the amps

    Cheers
    I agree... i think a maybe 25or 24 would be sufficient. i tried this and my temps were 98 F it was aprx -10 F
    Summit. MM 2200kv
    E-Revo VXL CVD's

  5. #125
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Quote Originally Posted by crusey View Post
    Did you try lowering the gearing and then running 4s ?

    4s geared for the same speed as 3s will only require 75% of the amps

    Cheers
    Yes, I ran 30/50 gearing with 4S.

  6. #126
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by fastmachine View Post
    Yes, I ran 30/50 gearing with 4S.
    It seems you did the opposite. 30/50 is very heavy and would take you way over 100 mph if your motor gets to its max RPM. I would try a much lighter gearing like 23/50. That gives the batteries more chance to keep up with what the systems asks.
    Nobody is born with experience

  7. #127
    RC Champion
    Join Date
    Nov 2010
    Location
    Lilydale, Victoria, Australia
    Posts
    2,843
    Think he means he reduced from 31/45 down to 30/50

    You are using the 1/10 Jacos which are 3.8" diameter is that right ?

    31/45 on 3s theoretical speed of 98 mph or so

    30/50 on 4s theoretical speed of 113 mph or so, not really that close

    Still way overgeared if you ask me

    23/50 would be theoretical 87 mph on 4s

    Cheers
    Slash Platinum
    Xerun 150 / Tenshock SC401 3500kv

  8. #128
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by crusey View Post
    Think he means he reduced from 31/45 down to 30/50

    You are using the 1/10 Jacos which are 3.8" diameter is that right ?

    31/45 on 3s theoretical speed of 98 mph or so

    30/50 on 4s theoretical speed of 113 mph or so, not really that close

    Still way overgeared if you ask me

    23/50 would be theoretical 87 mph on 4s

    Cheers
    Agreed. I didnt see the 31/45. I assume you used 3.7 as voltage. Still insane speeds. Lol.
    Nobody is born with experience

  9. #129
    RC Champion
    Join Date
    Nov 2010
    Location
    Lilydale, Victoria, Australia
    Posts
    2,843
    Yeah 3.7 and think he is running Jaco 1/10 foams @ 3.8" diam

    Pretty sure he quoted 55 mph on 2s

    Cheers
    Slash Platinum
    Xerun 150 / Tenshock SC401 3500kv

  10. #130
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by crusey View Post
    Yeah 3.7 and think he is running Jaco 1/10 foams @ 3.8" diam

    Pretty sure he quoted 55 mph on 2s

    Cheers
    Not sure if those are the low profile versions. I thought those always had the carbon look. If not, they are even 4.16" instead of 3.87".
    Nobody is born with experience

  11. #131
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Quote Originally Posted by Petertje60 View Post
    It seems you did the opposite. 30/50 is very heavy and would take you way over 100 mph if your motor gets to its max RPM. I would try a much lighter gearing like 23/50. That gives the batteries more chance to keep up with what the systems asks.
    3S + 35/50 = 70 mph
    4S + 30/50 = 68 mph

    Quote Originally Posted by crusey View Post
    Think he means he reduced from 31/45 down to 30/50

    You are using the 1/10 Jacos which are 3.8" diameter is that right ?

    31/45 on 3s theoretical speed of 98 mph or so

    30/50 on 4s theoretical speed of 113 mph or so, not really that close

    Still way overgeared if you ask me

    23/50 would be theoretical 87 mph on 4s

    Cheers
    The 30T pinion is the smallest one I have at the moment. I'll have to try 25/55. The foams are 4.23" in height. I also have some higher rated ******* batteries on the way.

  12. #132
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    I think 25/55 will possibly get you to higher top speeds because the lighter gearing asks less power to accelerate. Theoretically you already come to 71 mph on 3S and 95 mph on 4S with 25/55.
    Nobody is born with experience

  13. #133
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    I tried running on 4S with 25/55 and it went slower. 4S just isn't going to work with this motor.

  14. #134
    RC Qualifier
    Join Date
    Jul 2011
    Location
    New Zealand
    Posts
    707
    3s on a 7700?

  15. #135
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    6S on a Neu 1115 2100kV?

  16. #136
    RC Champion
    Join Date
    Nov 2010
    Location
    Lilydale, Victoria, Australia
    Posts
    2,843
    Yeah that might work, 65 amps or so max

    Cheers
    Slash Platinum
    Xerun 150 / Tenshock SC401 3500kv

  17. #137
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Other than the speed results, it was a good day. I made many 70 mph passes today, over and over. Didn't break a single part.

  18. #138
    RC poster
    Join Date
    Apr 2011
    Posts
    9
    That's crazy speed... I'm thinking about doing the mmp 4600kv setup in my merv cuz I'm sick of the high temps, do you guys think two of the new spc 2225mah 25c 2s lipos run in parallel will supply enough amps for the motor? I figured this setup should be able to supply about 110 amps

  19. #139
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by MaxxMan3.3 View Post
    That's crazy speed... I'm thinking about doing the mmp 4600kv setup in my merv cuz I'm sick of the high temps, do you guys think two of the new spc 2225mah 25c 2s lipos run in parallel will supply enough amps for the motor? I figured this setup should be able to supply about 110 amps
    I have the MMP/4600 combo and it works fine. I use 2 3S 1500mAh 30C packs and those work fine. Your batteries can deliver 934.5W which should be fine. Mine deliver less amps, but due to the higher voltage they deliver more power (1134W).
    Nobody is born with experience

  20. #140
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Quote Originally Posted by MaxxMan3.3 View Post
    That's crazy speed... I'm thinking about doing the mmp 4600kv setup in my merv cuz I'm sick of the high temps, do you guys think two of the new spc 2225mah 25c 2s lipos run in parallel will supply enough amps for the motor? I figured this setup should be able to supply about 110 amps
    There's a very noticeable difference between my Boost 2S 2450mah 50c and my SPC 2S 2300mah 20c. I would get a pair of the ******* ********** 2S 2250mah 65c.

  21. #141
    RC poster
    Join Date
    Apr 2011
    Posts
    9
    alright thanks, so how are the runtimes you guys are usually getting? and on a side note, I told the guy at my LHS I planned to put the mmp in my merv..and he gave me a weird look and said I was crazy...obviously he doesn't understand

  22. #142
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by MaxxMan3.3 View Post
    alright thanks, so how are the runtimes you guys are usually getting? and on a side note, I told the guy at my LHS I planned to put the mmp in my merv..and he gave me a weird look and said I was crazy...obviously he doesn't understand
    I get over half an hour from 2 Kypom 1500mAh 3S 30C batteries.
    Nobody is born with experience

  23. #143
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Quote Originally Posted by MaxxMan3.3 View Post
    alright thanks, so how are the runtimes you guys are usually getting? and on a side note, I told the guy at my LHS I planned to put the mmp in my merv..and he gave me a weird look and said I was crazy...obviously he doesn't understand
    I've never really timed it, but 4900mah lasts for quite a long time. That's funny you should mention that. I was talking with a guy at the LHS about putting the MMP on my truck and he said it wouldn't fit.

  24. #144
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    People who put a MMP in a Merv are in fact a bit crazy and if you are honest, it doesn't really fit. At least not easily.
    But hey, what's the problem?
    Nobody is born with experience

  25. #145
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    What do you guys think of ******* ********** 1800mah 3S 65/130C in parallel, with 4x/4x gearing? This combo would provide up to 234 amps, or at least more amps than the Boost 3S 45/55C. Some of you guys think this is too much gearing, but every time I gear down it goes slower.
    Last edited by fastmachine; 12-10-2011 at 11:03 PM.

  26. #146
    RC Champion
    Join Date
    Nov 2010
    Location
    Lilydale, Victoria, Australia
    Posts
    2,843
    When are you going to buy yourself a wattmeter and take the guessing out of it ?

    Why not find out exactly what your batteries are doing ?

    Cheers
    Slash Platinum
    Xerun 150 / Tenshock SC401 3500kv

  27. #147
    RC poster
    Join Date
    Jan 2012
    Posts
    11
    is the motor the cm36 or 1406 castle

  28. #148
    RC Qualifier
    Join Date
    Oct 2011
    Location
    RC World
    Posts
    345
    I have a Rally VXL with the Traxxas 11.1 volt batteries in it. They are 2 bucks cheaper than the "big" 7.4 volteres. I like it cause it has a lot of power and run time. Just randomly saying something...

  29. #149
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    I recently made a few changes for the next round of this build. My previously used batteries were 3S 1800mah 45/55c, in parallel. They were struggling to feed this motor and would not allow the truck to go any faster than 70 mph. I already hit 62 mph on 2S, so the batteries were a big problem. I needed some serious firepower, so I decided to use some 3S 2200mah 65/130c batteries. This will provide me with 286 amps vs 162 amps from the old setup. These batteries are MUCH larger so they required me to cut out the bottom of the chassis and use the T-Bone chassis brace as the bottom support. Now to keep the batteries in place, I ended up using my wifes hair ties that wrap around the battery door clips, from one side to the other. They ended up being an easy and perfect solution for it.

    The stock rear driveshafts have failed on me a few times after several high speed passes, so I installed the HR steel CVD's. They look like quality pieces and can be installed without removing the rear diff. The pin is captured by the blue sleeve. The blue sleeve cannot move outward because it has a lip on the other side that keeps it from sliding.

    I also trimmed the rear wing so it basically has 4 fins and nothing else, for straight line stability. I'm starting out with 43/45 gearing.














  30. #150
    RC Enthusiast
    Join Date
    Mar 2014
    Posts
    22
    Thanks for the PM. Awesome that your back at it (I thought you sold your merv lol). Looks like I'll be following in your footsteps with the battery mod :-P! It's just interesting that 90C of juice cannot get up to the theoretical top speed.

    If you can't find enough room to run it, you can always come down to my area (Lehigh Valley, PA) and run it in this barely used back commuter parking lot lol.

    Last edited by jhengis; 03-14-2014 at 02:39 PM. Reason: additional photo

  31. #151
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    I did some 2S testing today to make sure everything is running right and hit a new best of 66.6 mph! That's with 43/45 gearing. 3S is going to be insane as long as my new batteries will do what I think they can do.

    I can still go further with the gearing. The 43T pinion is the largest that will fit the Tenbol mount without modification, but with a little trimming I'm sure I could fit a 45T or 47T pinion, from Robinson Racing. I also have a 43T HR spur gear, but it's metal though, and would probably tear up the aluminum pinion after a while. So hitting 70 mph should easily be possible on 2S with some gearing changes.

    I picked up some more wheel weights to use on the front bumper to keep the front end down. I'm now using 4 of them. This helps out tremendously with eliminating wheelies and being able to apply full power at a lower speed. I also moved my GPS to a better and safer location.





    Quote Originally Posted by jhengis View Post
    Thanks for the PM. Awesome that your back at it (I thought you sold your merv lol). Looks like I'll be following in your footsteps with the battery mod :-P! It's just interesting that 90C of juice cannot get up to the theoretical top speed.

    If you can't find enough room to run it, you can always come down to my area (Lehigh Valley, PA) and run it in this barely used back commuter parking lot lol.
    No problem. Having the proper place to run it is very important. Why won't the airport let me borrow their runway for 30 mins? Haha

  32. #152
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    I would really gear down when trying 3S. A close to 1:1 gearing will only put unnecessary stress on batteries and motor and you won't get anywhere close to the theoretical top speed.

    With a lower gearing, your will reach top speed way faster and need a shorter runway.
    On 3S with 31/45 you will still get a theoretical top speed of 109mph.
    Nobody is born with experience

  33. #153
    RC Enthusiast
    Join Date
    Mar 2014
    Posts
    22
    So you're recommending 31/45 ratio?

  34. #154
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    I was going to make a 3S pass yesterday but it decided to rain, so that was a no go.

    Quote Originally Posted by Petertje60 View Post
    I would really gear down when trying 3S. A close to 1:1 gearing will only put unnecessary stress on batteries and motor and you won't get anywhere close to the theoretical top speed.

    With a lower gearing, your will reach top speed way faster and need a shorter runway.
    On 3S with 31/45 you will still get a theoretical top speed of 109mph.
    In my experience and with my setup, gearing down just makes you go slower. I've gone faster and faster every time I've geared up using 2S, 3S, and 4S. I have never once gone faster by gearing down. Using the speed calculator, it says I should be able to hit 66 mph with a 25T pinion, on 2S. I guarantee you that will not happen. That speed calculator is pretty useless. The only way to know how fast you can go is to go out on the road and test.

    Quote Originally Posted by jhengis View Post
    So you're recommending 31/45 ratio?
    If you want to go slower, sure. If you want to go fast, you need 4x/4x gearing and the best batteries on the market.

  35. #155
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by fastmachine View Post
    In my experience and with my setup, gearing down just makes you go slower. I've gone faster and faster every time I've geared up using 2S, 3S, and 4S. I have never once gone faster by gearing down. Using the speed calculator, it says I should be able to hit 66 mph with a 25T pinion, on 2S. I guarantee you that will not happen. That speed calculator is pretty useless. The only way to know how fast you can go is to go out on the road and test.
    The speed calculator gives theoretical top speeds. Things like drag and resistance make it pretty impossible to reach those speeds. But as long as your stay below 60mph, you will get pretty close.
    If the speed calculator gives a theoretical top speed of for example 150mph with a Merv, I guarantee you that a gearing with a theoretical top speed of 100mph will give you a higher top speed in real life.
    Compare it with trying to accelerate from a stand still in a 1:1 car in 5th gear. Simply wont work. Of course 5th gear will have a higher top speed than 1st gear, but since a Merv has only one gear and you have to start from a stand still, you need to pick somewhere between 1st and 5th gear to maximize the top speed.

    Just try both 31/45 and 43/45 on 3S and see which top speeds you get. I would be surprised if the 43/45 gives the best result.
    Nobody is born with experience

  36. #156
    RC Enthusiast
    Join Date
    Mar 2014
    Posts
    29

  37. #157
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Just hit 77.1 mph on 3S! I used 43/45 gearing. This was my first pass with the new battery setup.


  38. #158
    RC Enthusiast
    Join Date
    Mar 2014
    Location
    BC,Canada
    Posts
    46
    I have a question, where is your antenna? I don't see a antenna in any of your pictures.
    1/16 E-Revo VXL

  39. #159
    RC Turnbuckle Jr. Petertje60's Avatar
    Join Date
    Jan 2011
    Location
    Rotterdam, Netherlands
    Posts
    8,617
    Quote Originally Posted by fastmachine View Post
    Just hit 77.1 mph on 3S! I used 43/45 gearing. This was my first pass with the new battery setup.

    Nice! 77.1mph.... That must look weird to see the little fella go that fast. Did you try the less tall gearing too?
    Nobody is born with experience

  40. #160
    RC Qualifier
    Join Date
    Dec 2010
    Location
    USA
    Posts
    457
    Quote Originally Posted by BlueFire View Post
    I have a question, where is your antenna? I don't see a antenna in any of your pictures.
    You can see it in a few of the pictures above. It's short and blue with a black cap.

    Quote Originally Posted by Petertje60 View Post
    Nice! 77.1mph.... That must look weird to see the little fella go that fast. Did you try the less tall gearing too?
    It's sounds pretty awesome, you can tell it's turning some big rpm. I only tried 43/45.

Page 4 of 5 FirstFirst ... 2345 LastLast

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •