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 or making a Paypal contribution here: paypal.me/SupportTMC

Delay Power Limiting By Running The Heater?

Discussion in 'Model S: Driving Dynamics' started by ratsbew, Dec 13, 2014.

  1. ratsbew

    ratsbew Member

    Joined:
    Mar 3, 2012
    Messages:
    371
    Will running the heater on full blast allow you extended track time by removing extra heat from the motor and battery?

    My understanding is that the Model S uses a regular resistance heater to heat the cabin when there isn't any waste heat available from the powertrain. After the powertrain warms up, that heat is available to heat the interior.

    Does anyone have experience with this? How about experience pushing the car on the track in very cold temperatures?
     
  2. ecarfan

    ecarfan Well-Known Member

    Joined:
    Sep 21, 2013
    Messages:
    10,354
    Location:
    San Mateo, CA
    I was not aware that the S ever used "waste heat from the powertrain" to heat the cabin. Is that correct?

    I thought all cabin heat came from a resistance heater dedicated to only providing heat to the cabin. But of course I could be wrong...
     
  3. pgiralt

    pgiralt Active Member

    Joined:
    Jun 16, 2013
    Messages:
    1,476
    Location:
    Cary, NC
  4. freds

    freds Member

    Joined:
    Apr 10, 2014
    Messages:
    247
    Location:
    Bothell, WA
    Actually I think you want to run the air-conditioning at full blast. I made the mistake of turning it off thinking I would get better times; but it went into power limiting real quick.
     
  5. Doug_G

    Doug_G Lead Moderator

    Joined:
    Apr 2, 2010
    Messages:
    15,851
    Location:
    Ottawa, Canada
    Yes it does. I know this for sure because when the car is cold soaked, the cabin heater takes about 6 kW. Once the drive train has warmed up by highway driving the cabin heater power consumption drops down to about 1 to 1.5 kW, even in very cold conditions. In comparison the cabin heater for the tiny cabin in the Roadster takes far more energy. Clearly they're using the heat pump to heat the cabin, using the motor coolant loop as the reservoir. (Yes there are indications they don't use the battery coolant loop - in extreme cold the battery never really gets properly warm during highway driving - too much exposed area underneath.)

    It's one of the reasons why driving the Model S in winter is MUCH more comfortable than driving the Roadster - you can keep the heat on!!!

    As for doing that on the race track, it probably makes no difference whatsoever. I believe the main reason that the motor gets too hot too quickly is that it's hard to remove the heat from the rotor.
     
  6. nwdiver

    nwdiver Active Member

    Joined:
    Feb 17, 2013
    Messages:
    2,402
    Location:
    United States
    When I was traveling through Oregon last winter I had the AC set to 'eco'. The car got noticeably warmer going up-hill vs downhill... I thought that was amusing...

    However... I'm pretty sure that running the heater 'full blast' will just increase the drain on the battery... I think the car is more than capable of cooling itself so sending more heat to the cabin is probably negligible.
     
  7. Nuke

    Nuke Member

    Joined:
    Feb 12, 2014
    Messages:
    188
    Location:
    Den Haag
    You guys also have the issue that 2 full power pickups is the max to get the limiter to kick in
     

Share This Page