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Old 10-03-2014, 01:40 PM   #1
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Default 17.5 tc actual run time?

Im just getting back into the hobby and have a few questions regarding actual rc run time with a brushless motor.

If you are running a 4WD TC, with a 2S 7.4 7500 90c battery, 17.5t with a 4.0 fdr what estimate on runtime would you expect? Bashing?

What type of run times are you getting with your RC?
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Old 10-03-2014, 01:55 PM   #2
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Well in spec tc a 6min race w 1min of warm up we use about 2200mah...
In you could see 15+min of run time per charge if your just bashing around but probably 20 wouldn't be smart (from a battery life standpoint)
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Old 10-03-2014, 02:49 PM   #3
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On a 7200mah battery, I can run my 17.5 super hard for 10+ minutes and still have a TON of battery life left. I've never once run my batteries down to cutoff (even in mod where I don't charge my batteries fully).

If you're just running around a parking lot or something, I bet it would last a good 30-40 minutes.
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Old 10-03-2014, 03:12 PM   #4
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On a 7200mah battery, I can run my 17.5 super hard for 10+ minutes and still have a TON of battery life left. I've never once run my batteries down to cutoff (even in mod where I don't charge my batteries fully).

If you're just running around a parking lot or something, I bet it would last a good 30-40 minutes.
That's awesome! Im planning to run my batteries down to cutoff. is that bad?
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Old 10-03-2014, 03:19 PM   #5
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What matters more is motor heat. On a warm day, my motor can come off at 160-165F after only 6+ minutes of hard running.
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Old 10-03-2014, 03:21 PM   #6
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As long as you keep it above a safe voltage, it wouldn't be bad, but I wouldn't recommend running til cutoff every time. Why do you think you'll be driving it til it stops?
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Old 10-03-2014, 03:34 PM   #7
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What matters more is motor heat. On a warm day, my motor can come off at 160-165F after only 6+ minutes of hard running.
^^^This... The car would most likely run for 25 minutes, provided that the motor didn't overheat. If the motor is timed conservatively, you'd probably be able to run the battery to the cutoff point without the motor killing itself. Conservative timing, of course, will vary between different motors/manufacturers.
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Old 10-03-2014, 03:41 PM   #8
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As long as you keep it above a safe voltage, it wouldn't be bad, but I wouldn't recommend running til cutoff every time. Why do you think you'll be driving it til it stops?

Im new to the hobby, Im looking for as much seat time as possible to hone my craft be it bashing or practice lapping.

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^^^This... The car would most likely run for 25 minutes, provided that the motor didn't overheat. If the motor is timed conservatively, you'd probably be able to run the battery to the cutoff point without the motor killing itself. Conservative timing, of course, will vary between different motors/manufacturers.
So on a Killshot 17.5, just run it at 0 timing?
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Old 10-03-2014, 03:58 PM   #9
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We were pushing 25 minutes full race pace at the vancouver enduro. Orca tx17.5, hobbywing 3.1, savox servo. 65-7500mah packs *c rating not important* 20 minutes would be safer. But we were winning lol
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Old 10-03-2014, 04:42 PM   #10
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Originally Posted by Boostgod View Post
Im new to the hobby, Im looking for as much seat time as possible to hone my craft be it bashing or practice lapping.



So on a Killshot 17.5, just run it at 0 timing?
You should be practising what you're going to be racing. 6min or so will be 20ish laps at most tracks anyway. That's lots of practice in one go.

After 6min. Cool the car off, check over it, make tweaks, then run again (without charging the battery even). After two runs, then charge the battery.

The other thing that can also overheat is tyres. Wear is proportionate to heat. Run them too long and you will ruin them. Especially if setup is not spot on.

0 timing on a Killshot? Nah, crank it up to 20deg and go from there until it is in the right temp range after a 6min run. My mate runs his 13.5 Killshot at 60deg. They can take plenty of timing and are designed for blinky. Hell, they are marked to 80!
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