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Reliability of Electric Motors on Track

Discussion in 'Model 3: Driving Dynamics' started by TheSuit, Jul 8, 2018.

  1. TheSuit

    TheSuit Member

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    Hoping someone knows this answer. I've heard that a dozen miles on a track is equivalent to 1,000 normal miles. When it comes to electric motors, how much would someone have to worry if they put a couple thousand miles on the track in a performance model 3?

    Also, if worst case scenario a motor went bad, anyone have an idea of how much to replace it?
     
  2. ewoodrick

    ewoodrick Member

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    Electric motors, as opposed to ICE, I feel, last for a lot, lot longer. Quite often, the only thing that is moving with friction is the shaft and the bearings. The wiring will tend to last forever, unless too much current is put through them.

    What will feel the difference are the batteries, brakes, transmissions and other things that move. They will tend to feel the pain.

    I've got a pond pump that runs 24x7. It ran for about 5 years before I had to clean the gunk out of it and then put it back in service.
    I had a LaserDisk that running at a cable company for about 5 years and then it went off the air. We went to check it and found the problem was that the disk had about a half inch of gunk built up on it. cleaned it and then it kept going.

    Now I will say that keeping a motor at 100% of rated capacity and not providing adequate cooling can be detrimental.
     
  3. xav-

    xav- Active Member

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    Then why do drive units fail so often? (Just wondering)
     
  4. xav-

    xav- Active Member

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    My understanding is that it’s covered by the 120k mile warranty. The other cool thing with dual motors is that if a drive unit fail the other drive unit will still work so you are not stranded (unlike me)
     
  5. ecarfan

    ecarfan Well-Known Member

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    They don’t. As a percentage of all Tesla vehicles produced, drive unit failure (meaning the car won’t move because of a problem with the drive unit) is rare. If it was common you would see multiple posts about it every day on TMC.

    I have a total of over 83K miles on my S (which I traded in for an X) and my X. I have never had a “drive unit failure”. And after 5+ years of volume vehicle production there are tens of thousands of Tesla owners who have had the same experience.
     
  6. Twiglett

    Twiglett Single pedal driver

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    If you’re planning on putting several thousand track miles on a car I’d be way more concerned about other stuff than an electric motor.
     
  7. TheSuit

    TheSuit Member

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    Like what? There's no transmission and the battery lasts pretty much forever. Tires, breaks, and suspension aren't prohibitively expensive. Thus the motor(s) are really the primary concern. Anyone know the cost to replace them and how they would handle being pushed to the limit on a regular basis?
     
  8. Twiglett

    Twiglett Single pedal driver

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    So you think the motor is a concern because it’s an unknown?
    How about the little things in an EV like the battery or the inverter?
     
  9. 12Pack

    12Pack Member

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    Does the M3 performance come with a resolution for the the battery/inverter heating issues? Have had my MS P100D on track once and it cut power within the first lap that I pushed it (after two warm-up / siting laps) because of this.
     
  10. JGard

    JGard Member

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    Can anybody speak to the battery life during a track day with one of these things? I'd love to take mine to COTA (once I get it), but it's about 25 miles away from my home and afaik, there are no publicly available chargers there. I'd hate to pay $500 for a track day, but only have enough juice to run like 10-15 laps and then have to head home
     
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  11. SSedan

    SSedan Member

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    As said battery and the inverter heat would be my concern.

    An ICE with all the reciprocating parts and valvespring wear would worry me more than the electronic motor itself.
     
  12. MP3Mike

    MP3Mike Well-Known Member

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    #12 MP3Mike, Jul 9, 2018
    Last edited: Jul 9, 2018
    The pinch point on the Model S isn't the inverter or battery, it is the motor, and more specifically the rotor which is very hard to cool. The Model 3 uses a PM motor so it doesn't have a problem with rotor heat like the Model S&X with their induction motors.
     
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  13. ℬête Noire

    ℬête Noire Active Member

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    #13 ℬête Noire, Jul 9, 2018
    Last edited: Jul 9, 2018
    Also, the Model 3 motor has an oil bath circulated by a paddle wheel with an oil filter (that the Model S/X drive units don't have). It is understood that the oil is then run through a heat exchange for the battery coolant. This allows them to air-cool away the heat with the front radiator or, as they don't seem to have resistive heating elements within the battery, use the heat from the motor to bring the battery up to optimal operating temp.

    To OP, of the few that have tried, so far nobody has found the Model 3 throttling on the track due to heat. Here's the first one I saw that tried but there have been more: Model 3 Track Day: Laguna Seca Also check out Mountain Pass Performance's more recent posts here.

    You'll see in that thread I linked that they completely cooked their brakes without the motor showing any signs of throttling.
     
  14. Knightshade

    Knightshade Active Member

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    Well, it uses one in the back.

    AWD/P models use induction in the front though.... (not sure if we know if they've made any significant cooling changes or anything yet for it though compared to the S/X units)
     
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  15. ℬête Noire

    ℬête Noire Active Member

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    The "burnout" skidpad video released by Tesla last week appears to confirm the expectation that there is going to be a lot less power (thus less heat) in the front motor. It'll be interesting to see whether or not Tesla found/feels it necessary to add active cooling elements to the front motor, as well.
     
  16. NickFie

    NickFie Member

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    More-frequent motor failure in first wave of Model S. Tesla had one or two redesigns, now there is good reliability.

    My early-adopter Tesla friend showed me his original drive unit in my first demo drive. It had developed problems, was replaced with newer design under warranty. When I was in the car it already was well over 100k miles.

    Will be interesting to see how oncoming wave of high battery capacity EVs do as thousands of owners accumulate millions of miles in diverse conditions.

    The older I get, the more I understand the value of experience.
     
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  17. ℬête Noire

    ℬête Noire Active Member

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    A lot of the motors they replaced hadn't failed outright, either. They were replacements for noise that, IIRC, ended up being power electronics related.
     
  18. MP3Mike

    MP3Mike Well-Known Member

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    The S&X drive train have a gear driven oil pump to keep things lubricated, but it doesn't have a filter, and doesn't work in reverse. The Model 3 rear motor uses and electric pump for lubrication and has a filter.

    We don't know what the front motor on the AWD/P Model 3s will be like yet.
     
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  19. Pkmmte

    Pkmmte Le meow

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    *SR motor with some PM.
     

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