TMC is an independent, primarily volunteer organization that relies on ad revenue to cover its operating costs. Please consider whitelisting TMC on your ad blocker and becoming a Supporting Member. For more info: Support TMC

Musk Says Model 3 Brakes Need Work, Firmware Update Coming in a 'Few Days'

Discussion in 'Model 3: Driving Dynamics' started by TMC Staff, May 22, 2018.

  1. TMC Staff

    Joined:
    May 19, 2017
    Messages:
    706
    Responding to Consumer Reports’ criticism of the Model 3’s braking ability, Tesla CEO Elon Musk tweeted Monday that the company will “make sure all Model 3’s having amazing braking ability at no expense to customers.” Consumer Reports said the Model 3’s stopping distance of 152 feet from 60 mph was far worse than any contemporary...
    READ FULL ARTICLE
     
  2. Peter Thomas

    Peter Thomas Member

    Joined:
    Jan 26, 2018
    Messages:
    71
    Location:
    Raleigh, NC
    Elon,
    Besides the software you may want to check the brake pads. I have had experience with hard long lasting brake pads which degrade the braking performance substantially.compared to the brake pads optimized for braking performance. As far as ride is concerned you may wan to offer an option, BMW M-3 or 325 like ride for performance enthusiast and Avalon like ride for people like me who don't go around corners very fast and desire a comfortable ultra smooth ride. Many people buy cars based on these two criterion. Just my 2 cents
     
    • Like x 1
    • Disagree x 1
  3. apacheguy

    apacheguy S Sig #255

    Joined:
    Oct 21, 2012
    Messages:
    4,986
    Location:
    So Cal
    Can someone explain how braking performance can be improved with firmware?
     
  4. McManX

    McManX Member

    Joined:
    Feb 23, 2016
    Messages:
    760
    Location:
    San Francisco, CA
    Musk tweeted about the ABS algorithm I believe.
     
  5. bro1999

    bro1999 Active Member

    Joined:
    Apr 26, 2016
    Messages:
    1,828
    Location:
    Maryland
    If the ABS software was not programmed correctly, and OTA update can theoretically fix that. If it's purely a software issue. Seems like Elon doesn't know if it is just a software issue though.
     
  6. bro1999

    bro1999 Active Member

    Joined:
    Apr 26, 2016
    Messages:
    1,828
    Location:
    Maryland
    I hope CR doesn't accept a brand new car from Tesla to test. Once the fix is available and applied, the same car(s) should be tested to see if the fix actually took care of the braking problem.
     
    • Like x 2
    • Funny x 1
  7. mrolsky

    mrolsky Member

    Joined:
    Sep 23, 2015
    Messages:
    6
    Location:
    United States
    upload_2018-5-22_11-10-20.png
    You are mixing up to elements lol - Braking was a firmware update - rest is about early production car and those changes of course wont happen based on over the air update
     
    • Informative x 2
  8. Peter Thomas

    Peter Thomas Member

    Joined:
    Jan 26, 2018
    Messages:
    71
    Location:
    Raleigh, NC
    My experience with Consumer Reports has been relatively good. Toyota Camry was rated as the most reliable car when I bought it and I ended up never having any issues with it other than the plastic door handles breaking which they fixed in the newer versions. I put 250,000 miles on the car so Consumer reports saved me a lot of money. A Lot of their criticism are based on driving so many other cars so they often have some merit. I know nothing about the Model 3 but I can tell you that Consumer reports reviews of other cars are often quite accurate. They are not biased by performance or other things that are typically not important to the average consumer. That is what Car and Driver is for.
     
    • Like x 1
  9. ILLCOMM

    ILLCOMM Member

    Joined:
    Sep 26, 2017
    Messages:
    138
    Location:
    USA
    I am not sure they can push an update to the ABS controller OTA. Usually the ABS controller is a separate and distinct controller (for obvious reasons). I think it is more likely they can push an update to regen during hard braking. If compromises were made on pad performance for longevity (less wear, worse peak performance), it's possible they were made with an assumption that regen would fill the performance gap - something an ICE car can't do. If regen isn't working on some cars as it should, that would explain a lot.

    This is pure speculation.
     
  10. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    8,984
    Location:
    Michigan
    Anything with a communication bus (or even a single IO line) can be updated (assuming it was programmed to allow it).
    It has to be (at least partially) an ABS update since the ABS system should allow maximum braking authority (up to wheel lock up) without the assistance of regen (case in point: full or cold pack with zero regen).
     
    • Informative x 1
  11. ILLCOMM

    ILLCOMM Member

    Joined:
    Sep 26, 2017
    Messages:
    138
    Location:
    USA
    Still not sure I'd believe ABS OTA updates are a capability. Seems ... risky. But, I understand your point and recognize that it's very possible.

    Just to clarify my point - if ABS is tuned out of the box to work a certain way with regen (as it would have to as you point out with full/cold pack) and in fact regen was not holding up its part of the bargain, then that's something that could theoretically be fixed OTA.

    That said, you bring up an interesting case - should a brake test in a Tesla be done with a full or cold pack so regen is off/diminished, or under more typical circumstances where regen can contribute significantly? And if you're Tesla would you dare optimize your braking system assuming regen is available when there are uncommon but not atypical situations where regen might be unavailable entirely??
     
    • Like x 1
  12. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    8,984
    Location:
    Michigan
    ABS at the basic level only kicks on when a wheel locks up. Up until that point the braking force is 100% based on the driver pedal pressure * booster assist. If you want to brake harder you push harder, so any fixed offset due to assumed regen can be bypassed by pushing harder.

    Where it gets funky is if the ABS system anticipates the force need to lock up a wheel. If (made up number) 15kPa locked the wheels the last two braking events, maybe it starts backing off at 14kPa. If that were the setup, then the extra torque of regen would be a critical factor in the calculation (how much regen during the two lock up events vs how much now).
    This type of system would be great in adverse conditions due to ability to reduce the number of lock up events and thus reduce stopping distance. The downside being if it 'learns' wrongly and overly reduces maximum braking, then you end up taking longer to stop.
     
  13. Daniel in SD

    Daniel in SD Active Member

    Joined:
    Jan 25, 2018
    Messages:
    2,532
    Location:
    San Diego
    We need an ABS expert here! That's not me but you can't do what you're describing because on the first stop you could be stopping on a wet surface and then the next stop you could stopping on a dry surface. The problem with any sort of self calibration is that most people don't drive around using the ABS very often. I've met people who have never used the ABS on their cars!
    It always feels to me like ABS is letting the wheels slip a little bit and then letting off the brake pressure. I don't think it's possible to predict how much traction the road surface has without actually getting slippage. I suppose the regen could confuse the ABS controller if it's also modulating the rear "braking" force. That would be a control system nightmare! It would be interesting to see if the same inconsistency in braking distance is seen with the regen off.
     
    • Informative x 1
  14. mongo

    mongo Well-Known Member

    Joined:
    May 3, 2017
    Messages:
    8,984
    Location:
    Michigan
    True dat, not me either.

    ABS usually works the way you mention.

    I agree the 'less that I think is possible' braking force method has issues. I'm probably over extrapolating from the "ABS calibration algorithm" tweet.

    Maybe the issue is in the slip detection routine? It starts seeing lock up when there isn't any?

    I think regen kicks off on lock up. At that point, ABS has to drop pressure anyway to go from slip to rolling traction and then ABS continues as normal (as long as regen stays off).
     
  15. Peter Thomas

    Peter Thomas Member

    Joined:
    Jan 26, 2018
    Messages:
    71
    Location:
    Raleigh, NC
    An important point for Tesla to consider:
    For Consumer Reports suspension or ride criticisms that Elon addressed in addition to the braking performance, the issue is whether the Model 3 suspension is tuned or designed for a BMW like ride where you feel the bumps but can corner very well or a Avalon like ride where you don't feel the bumps and but cornering is compromised. Since I don't go around corners very fast, I prefer the Avalon ride. Toyota sells a lot more cars than BMW so I would think that if Tesla is interested in maximizing sales they would offer both suspension options. Not all drivers have a the same perspective. Isn't that what it is all about-freedom of choice? Instead of Tesla focusing on performance people only, I suggest an optional suspension package with a ultra smooth suspension with sound dampening like that found in Avalon, most of the Toyota line including the Corolla and higher end Lexus cars since many of the average consumer prefer a smooth quiet car to cruise in.
     
    • Funny x 1
  16. MP3Mike

    MP3Mike Well-Known Member

    Joined:
    Feb 1, 2016
    Messages:
    8,774
    Location:
    Oregon
    @Peter Thomas Tesla already made their decision when they softened the suspension back in December, and then offer that as a retro-fit for anyone that got the overly stiff suspension that asks/complains about it. (From what I have read they split the difference between your examples to try to make the most number of people happy with a single suspension option.)
     
    • Like x 2
  17. Peter Thomas

    Peter Thomas Member

    Joined:
    Jan 26, 2018
    Messages:
    71
    Location:
    Raleigh, NC
    Are people happy with the new suspension? Are performance people satisfied with it? And does it compare to Toyota or Lexus in ride?
    If so, problem solved. If not, Tesla may want to explore splitting into two options or investigating active suspensions.
     
  18. MP3Mike

    MP3Mike Well-Known Member

    Joined:
    Feb 1, 2016
    Messages:
    8,774
    Location:
    Oregon
    @bro1999 Elon never offered to provide them a car for testing. All he said was "Also, Consumer Reports has an early production car. Model 3 now has improved ride comfort, lower wind noise & many other small improvements. Will request that they test current production."

    In other words they know early production had issues, so how about you try to get a car more recently built to see how we are doing now instead of how we were doing almost a year ago.
     
    • Informative x 1
    • Like x 1
  19. xav-

    xav- Active Member

    Joined:
    May 26, 2016
    Messages:
    1,187
    Location:
    Orange County CA
    I love the new suspension. I would not categorize it as too firm. It’s the perfect balance.
     
  20. MrAustraliaTax

    Joined:
    Mar 1, 2015
    Messages:
    238
    Location:
    Melbourne
    This is an excellent response by Musk.

    In the past, he has resorted to ad hominem attacks (attacking the messenger - eg Broder) or suing (eg Top Gear).
     
    • Like x 2

Share This Page

  • About Us

    Formed in 2006, Tesla Motors Club (TMC) was the first independent online Tesla community. Today it remains the largest and most dynamic community of Tesla enthusiasts. Learn more.
  • Do you value your experience at TMC? Consider becoming a Supporting Member of Tesla Motors Club. As a thank you for your contribution, you'll get nearly no ads in the Community and Groups sections. Additional perks are available depending on the level of contribution. Please visit the Account Upgrades page for more details.


    SUPPORT TMC