question regarding max power (watts) on TP motors

[dk10438]

I was looking at my logs on a recent speedrun which is powered by a TP4040-2850CM on 6S. According to the TP website, the motor is rated for 1650W continuous but max power for 10 seconds is 4200W. According to my logs, I was drawing about 6000W during my pull which lasted a couple of seconds. Am I exceeding the limits of the motor? Or am I pretty much doing that with the entire car during speedruns??

 

[Moirae]

I think you're fine as long as you can cool it. I think you need to be more worried about rpms over how much wattage. Someone correct me if I'm wrong.

Those cm motors are tough, I had one hit about 240f and it still works like it was new lol.

 

[LicketySplit]

I was looking at my logs on a recent speedrun which is powered by a TP4040-2850CM on 6S. According to the TP website, the motor is rated for 1650W continuous but max power for 10 seconds is 4200W. According to my logs, I was drawing about 6000W during my pull which lasted a couple of seconds. Am I exceeding the limits of the motor? Or am I pretty much doing that with the entire car during speedruns??

Should have pulled around 240 amps. Is that what your log says?

 

[dk10438]

Actually pulled 358 amps

 

[LicketySplit]

Actually pulled 358 amps

Should be good then. I’m still trying to figure out the math since it never adds up. Amps are the most important thing as long as you don’t over-rev the motor.

 

[Moirae]

Should be good then. I’m still trying to figure out the math since it never adds up. Amps are the most important thing as long as you don’t over-rev the motor.

Doesn't the motor pull the amps? wouldn't that mean amps more of an esc problem and not a motor problem? IE him pulling even 400 amps not going to "harm" the motor?

 

[LicketySplit]

Doesn't the motor pull the amps? wouldn't that mean amps more of an esc problem and not a motor problem? IE him pulling even 400 amps not going to "harm" the motor?

Exactly.

 

[K-BASH]

All tp motors are way underrated.ive got 7k from 4500w 3650..4040cm should also do 7000w.cm motor pull far less amps than regular motors....it's a 80,000rpm motor so wouldn't worry about overrevving it...Temps are about only thing that'll kill it...I've never killed any of mine an well worth spending more for cm on any application...
Motor could take 8s...look at ONLY volts,kv,rpms...that's how many volts that motor will take before overrevving that motor..lol on a 8s hit car wouldn't hold over 28 volts on hit..
Here's a 8s log from tp5670-1270kv an it's a 12000w motor..motor wasn't hot at all..has lots more in it

 

[K-BASH]

I was looking at my logs on a recent speedrun which is powered by a TP4040-2850CM on 6S. According to the TP website, the motor is rated for 1650W continuous but max power for 10 seconds is 4200W. According to my logs, I was drawing about 6000W during my pull which lasted a couple of seconds. Am I exceeding the limits of the motor? Or am I pretty much doing that with the entire car during speedruns??

I don't think it's possible to exceed limits in speedrunning. In the end motor temp tells all.it'll get reel hot reel fast when it's maxed out..couldn't imagine 4040 putting out more than 8000w so your getting close to it's limits I'd imagine.4040cm,4050cm,4060cm are the same price 160$$..so always go for biggest 1 ya can fit for best performance.

 

[dk10438]

I don't think it's possible to exceed limits in speedrunning. In the end motor temp tells all.it'll get reel hot reel fast when it's maxed out..couldn't imagine 4040 putting out more than 8000w so your getting close to it's limits I'd imagine.4040cm,4050cm,4060cm are the same price 160$$..so always go for biggest 1 ya can fit for best performance.

yeah, it's usually exceeding the limits of the driver that causes the problems, LOL. This motor is in my serpent so I'm space constrained. Motor temps were 110 after a 900 foot run and I was full throttle for about 1.5 seconds before I lifted so I don't think I really pushed the limits of the motor yet.

 

[K-BASH]

yeah, it's usually exceeding the limits of the driver that causes the problems, LOL. This motor is in my serpent so I'm space constrained. Motor temps were 110 after a 900 foot run and I was full throttle for about 1.5 seconds before I lifted so I don't think I really pushed the limits of the motor yet.

Do ya have a log from last pass???very surprised light an efficient serpent is throwing huge #'s under 130 on 6s...

 

[dk10438]

here's the log....

 

[LibertyMKiii]

I was looking at my logs on a recent speedrun which is powered by a TP4040-2850CM on 6S. According to the TP website, the motor is rated for 1650W continuous but max power for 10 seconds is 4200W. According to my logs, I was drawing about 6000W during my pull which lasted a couple of seconds. Am I exceeding the limits of the motor? Or am I pretty much doing that with the entire car during speedruns??

How hot is your motor getting?
Theoretically speaking.... Your ESC may put 6kW into it and only 4,200 converted to mechanical movement. The rest converts to heat....

You can absolutely squeeze a bit more out of the motors but in general their ratings are pretty accurate.

 

[dk10438]

motor was only about 105-110 degrees so lots of room there but it was a pretty short pull. 900 feet and 1.5 seconds full throttle.

 

[K-BASH]

here's the log....

View attachment 283905

I'm no serpent pro by no means...but with ripple that high,watts that high I say ya got some major resistance holding car back somewhere...if your cranking out 7000w on 6s I'd think ya should be well above 130mph...ran my vendetta on 6s once with tp3650-3080kv 36×84 an it cranked out 7000w an ran a 130...see if I can find log....ya could also be really overgeared....esc temp an throttle pull can also help diagnose..over 3v of ripple tells me your working mmmx8s hard.esc temp would clearly show
@phildogg would probly know best since he has a very similar setup..imo looks like cars being held back..if your at 350a an 3v+ ripple that mmx8s is working way harder than it should be for the speeds your running

 

[dk10438]

well the wedge body isn't particularly aerodynamic so that might be part of the problem

 

[K-BASH]

I'd take car outside where's it's cooler,bench test run car at 5-10% throttle for a few minutes on a stand an go over entire car with temp gun looking for any hot spots.any bad resistance will be much warmer...that will be your problem areas that will need fixed..could be 1 screw to tight on a pulls or anything...I bet you'll notice some hot spots...cause a 1/10th on 6s pulling 350a and 7000w should be running 140+++ if everything is good....your log an perimeters are all showing a major issue somewhere...try the 15 min temp gun test an I bet something gets hot as shiot..you built a badass car an I don't want to see ya tear things up cause 1 screw somewhere is to tight or rubbing.....

 

[LibertyMKiii]

motor was only about 105-110 degrees so lots of room there but it was a pretty short pull. 900 feet and 1.5 seconds full throttle.

Gotcha for that throttle pull time that makes more sense.
I would say that all seems normal.

Gearing likely isn't there for high speeds. The amperage is high due to the short throttle pull.

 

[dk10438]

I'm wondering if mixing bullets with QS8s could be a problem?
The male bullet is only 7mm long (which is significantly shorter than the male connector of a QS8) and it seems to barely extend past the resistor in female connector? Does anyone know??

https://www.arrmaforum.com/threads/...-connector-matter-when-using-with-qs8s.60933/

 

[Diem Turner]

I'm wondering if mixing bullets with QS8s could be a problem?
The male bullet is only 7mm long (which is significantly shorter than the male connector of a QS8) and it seems to barely extend past the resistor in female connector? Does anyone know??

https://www.arrmaforum.com/threads/...-connector-matter-when-using-with-qs8s.60933/

Could be. I've had connection issues when trying to use Castle bullets with QS8s. I'd recommend extracting some of the pins from a QS8 and using those instead. That's what I do anyways and I haven't had any issues ever since.