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Adding RX pack for servo & AMB, 2s LiPo for Motor ONLY?

Adding RX pack for servo & AMB, 2s LiPo for Motor ONLY?

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Old 10-31-2012, 10:56 AM
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Default Adding RX pack for servo & AMB, 2s LiPo for Motor ONLY?

I would like to know if there are any Advantages, or disadvantages to adding an RX pack in my car (dirt oval) to power only the steering servo and AMB transponder, while my main 2s LiPo would just power the motor. Would this save me a little voltage in my LiPo? I'm hoping that someone has tried this.

I need to find some more speed in my current setup. Our rules state:
21.5 Motor (Roar Approved)
Blinky Mode ESC
2s 7.4V LiPo's ONLY (hardcase)

My Equipment:
Thunder Power 21.5, Revtech 21.5, Novak SS 21.5, Novak Ballistic 21.5
Castle Creations MMP, Brushless Hobbies LT4, SpeedPassion Citrix
Gens Ace 5000Mah 50C, Gens Ace 5000Mah 65C, Turnigy 5.0Mah 40C
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Old 10-31-2012, 01:08 PM
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Wont help you much, would mostly just add weight. you wont increase voltage, youd decrease amp draw, but only minimally.
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Old 10-31-2012, 05:39 PM
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Originally Posted by Hoese37 View Post
Wont help you much, would mostly just add weight. you wont increase voltage, youd decrease amp draw, but only minimally.
Yes, with that what you will gain in the loss of amp draw you will give up in the extra weight.

You might try removing a few or adding a few degrees of timing in the motor. That will affect ( slightly ) the torque/rpm ratio hopefully taking advantage of the reduction of wheel spin or extra top end. I use this when a pinion change is too much.
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Old 10-31-2012, 06:01 PM
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Originally Posted by OneBadDude View Post
I would like to know if there are any Advantages, or disadvantages to adding an RX pack in my car (dirt oval) to power only the steering servo and AMB transponder, while my main 2s LiPo would just power the motor. Would this save me a little voltage in my LiPo? I'm hoping that someone has tried this.

I need to find some more speed in my current setup. Our rules state:
21.5 Motor (Roar Approved)
Blinky Mode ESC
2s 7.4V LiPo's ONLY (hardcase)

My Equipment:
Thunder Power 21.5, Revtech 21.5, Novak SS 21.5, Novak Ballistic 21.5
Castle Creations MMP, Brushless Hobbies LT4, SpeedPassion Citrix
Gens Ace 5000Mah 50C, Gens Ace 5000Mah 65C, Turnigy 5.0Mah 40C
Those batteries that you are using aren't helping at all. Get or borrow a higher end battery and see if that makes a difference. If not then it's in your set up of the car.
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Old 10-31-2012, 06:13 PM
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Originally Posted by HawaiiBob View Post
Those batteries that you are using aren't helping at all. Get or borrow a higher end battery and see if that makes a difference. If not then it's in your set up of the car.
Good catch, Thumbs up on that!
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Old 10-31-2012, 06:22 PM
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I currently run a separate pack, but not to gain speed. It works quite well. Can you run a shorty pack?
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Old 11-01-2012, 07:39 AM
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I can run a shorty pack. So the weight there would even out. Can you tell me the reason you run an RX pack if it is not for speed?

Now when you say my batteries aren't helping the situation, just WHAT battery are you suggesting? Gens Ace is a pretty highly rated and recommended battery!
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Old 11-01-2012, 11:49 AM
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Originally Posted by OneBadDude View Post
I can run a shorty pack. So the weight there would even out. Can you tell me the reason you run an RX pack if it is not for speed?

Now when you say my batteries aren't helping the situation, just WHAT battery are you suggesting? Gens Ace is a pretty highly rated and recommended battery!
Actually running a shorty and an extra 300-460mah pack will weigh less than a 5000. I run a separate pack for a few reasons:
  1. My ESC has no BEC. So it's either run an external BEC or a second pack.
  2. My receiver resets with voltage fluctuations >.5v. So running a HV servo doesn't work well with the draw that the motor puts on the system in my case.
  3. I need weight in the front and don't like to add dead weight. The shorty with a 460mah pack on the servo puts a lot of weight up front.

I'm using the Turnigy A-Spec shorty packs and am having decent luck. They seem to be "unbelievable" for the first few laps and level out to "Wow, these are great" throughout the balance of the run.
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Old 11-01-2012, 02:33 PM
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Sounds like this might be what I'm looking for! The weight of the RX pack can be mounted about anywhere towards the left side of my car and I'm sure I can scale it back to what I have on each corner!

I'm glad to hear somebody else out there is running the Turnigy LiPos! Although I run my Gens Ace more than my Turnigy's for the features. I see that SMC is making a new Shorty 2s 7.4V 4600 70C which will be added in my pit box in the very near future!
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