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Old 03-05-2014, 04:04 PM   #16
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Hobbywing was better than Tekin or Novak. Tekin and HW had the same peak rpm from motor but the HW showed much better torque. That is why the oval racers prefer them. Castle seems to show very good on the track also but not tested. Testing was done on a TurboDyno setup for sensored/brushless. New HW's (V3 and 3.1) seem to be better yet but from a performance standpoint in oval but we did not dyno them.
But what makes the difference in torque, drive frequency?
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Old 03-05-2014, 04:13 PM   #17
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No way to rely on your tests when there are many ways to setup a Novak Blinky Esc !!!! On the dyno vs the track is also another issue. Novak drive frequency is adjustable, unlike most other brands... More tests are necessary before reaching any real conclusion...
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Hobbywing was better than Tekin or Novak. Tekin and HW had the same peak rpm from motor but the HW showed much better torque. That is why the oval racers prefer them. Castle seems to show very good on the track also but not tested. Testing was done on a TurboDyno setup for sensored/brushless. New HW's (V3 and 3.1) seem to be better yet but from a performance standpoint in oval but we did not dyno them.
Oval racing is the true test of torque in your motor, battery and esc combo. If any one is a little weak it will show up. Racers hunt for hundredths of a second per lap. At the Spektrum/CRC race .05/lap was the difference between the "A" and the "C".
In on-road the variability in lap time mainly comes from driving inconsistency. A good oval racer can keep his laps within a couple of tenths when not in traffic.
I actually look for my top 20 average to be .1 slower than my fast lap and my last 5 to be about .3 off of the fast lap from motor heat and lower voltage.
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Old 03-05-2014, 04:42 PM   #18
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I was also wondering about how your measering torque from one esc to the next. Even on spec esc's you can adjust certain paramiters. On my hobbywing justock I can set the "punch", and on my tekin rs spec I can adjust min throttle. I am assuming these to be very similar adjustments in both esc's, just named differently. These adjustment definately alter the amount of torque the motor produces as the car shows a noticible difference in acceleration as you alter the settings. I woukd be willing to bet that with a given motor, most esc's could be adjusted to give similar readings on a dyno. At least give readings that are close enough to have no difference once placed in race conditions.

As for the OP, I like the ESC's that offer tunablity via a computer. I like to see the numbers of my adjustments, not just look for blinking lights.
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Old 03-05-2014, 05:37 PM   #19
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But what makes the difference in torque, drive frequency?
Drive frequency refers to the PWM that is done at less than full throttle. It has no effect at full throttle, since no PWM occurs then.

The difference in torque is due to the difference in "on" resistance of the MOSFETS used, all else (battery and wire resistance) being equal.
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Old 03-05-2014, 06:22 PM   #20
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Drive frequency refers to the PWM that is done at less than full throttle. It has no effect at full throttle, since no PWM occurs then.

The difference in torque is due to the difference in "on" resistance of the MOSFETS used, all else (battery and wire resistance) being equal.
The on resistance and phase voltage drop of all good ESC is so low I doubt it makes any different that would be seen on a dyno and certainly not seen on track.

But just incase you think it is.

HW V3/V3.1 0.0003 ohm
Tekin RS 0.0003 ohm
Tekin RS Pro 0.00015 ohm.
LRP Flow worksteam calculated from specs 0.00055 ohm
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Old 03-05-2014, 08:34 PM   #21
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The on resistance and phase voltage drop of all good ESC is so low I doubt it makes any different that would be seen on a dyno and certainly not seen on track.

But just incase you think it is.

HW V3/V3.1 0.0003 ohm
Tekin RS 0.0003 ohm
Tekin RS Pro 0.00015 ohm.
LRP Flow worksteam calculated from specs 0.00055 ohm
I doubt that I could feel a difference in power between any of the high end ESCs. It's the low-priced ones running lower-turn motors that I might notice.

Thanks for the specs, but I'm already pretty well-informed on ESCs.

To be fair, I don't expect a $60 ESC to have the same specs as a $200 ESC.

The original question was 'will an ESC rated at 120A have any advantage over one rated at 45A' (I assume from the same manufacturer). The answer is yes, however slight it might be. The advantage becomes greater with lower-turn motors. The OP mentioned a 13.5 turn, which I consider to be relatively low.
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Old 03-05-2014, 09:35 PM   #22
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Apologies I probably shouldn't have quoted your post my response was aimed at the Tekin vs HW torque with IR being the difference between the two.

IR of a 45A ESC is still noticably lower than battery and wire resistance so I doubt it would make any difference in power output compared with a 120A ESC with a less powerful motor.

Smaller heatsink ie lower EG, no fan, thinner and lighter wires would probably add up to a faster car with the cheaper ESC. (Local racers believe they do)
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Old 03-06-2014, 04:35 AM   #23
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As you guys know power measured in watts is the product of rpm and torque. All I can say is since they can't change the rpm at the top, they can change how they get there. All of the settings were set to produce maximum power up to the free rev state.
I also test motors on a Fantom dyno. For those not familiar with it, a motor is given a 5 volt plug start and accelerates a flywheel. The torque is calculated by how fast the rpm increases from a dead stop. Differences can be seen there also. And just to note, timing advance on the motor has a sweet spot on that torque number. For a D3.5 (13.5, 17.5 and 21.5) it is 17 to 22 on the end bell. Or 47 to 52 degrees total.
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Old 03-06-2014, 04:47 AM   #24
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As a side note: I have Castle Mamba Max Pro, HW Juststock, 120a v2 and 1S. I keep the Juststock as a backup. It just doesn't produce the punch, brakes or drive smoothness that the other three do. I am a old dog thats done this for over 20 years and I notice the difference. I am not a top flight driver but I am usually in the upper third at any large event. If you are just starting out you will not feel that difference.
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Old 03-06-2014, 02:29 PM   #25
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I agree there is a difference between ESCs I have seen if first hand (blinky ESCs all being equal is a myth) but IMO it isn't due to IR.
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Old 03-07-2014, 09:23 AM   #26
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Running in classes with limited power like 1s 13.5t blinky in GT12 (think cheap 1/12th circuit) their is a difference in acceleration from dead slow and stop corners up to full speed between the cheap esc and the high end esc. Top speed is identical as old dude has said, personally I would say they are fairly well matched from mid range upwards. The difference is much less noticeable on 2S.

Running out and buying a $200 will only benefit you on the track if you can run the whole race without a single crash.
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Old 03-07-2014, 10:08 AM   #27
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One thing to note, however, between a v3 and a Justock is that they DO have different firmwares. The v2.1 firmware on a Justock is OK, but the v3 firmware is really the one that got Hobbywing all the big signings (Hara, Lemieux, Levanen, Moore, etc...)

A better comparison would be between a 60a/120a v2.1, with identical firmwares. These ESCs are almost similar and would be pretty interesting to see how it turns out.
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