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

Car and driver VP9 launches

Discussion in 'Video' started by TEG, Jan 24, 2008.

  1. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,252
    Location:
    Silicon Valley
    #1 TEG, Jan 24, 2008
    Last edited by a moderator: Mar 13, 2016
    Traction control off





    Traction control on
     
  2. doug

    doug Administrator / Head Moderator

    Joined:
    Nov 28, 2006
    Messages:
    15,914
    Location:
    Stanford, California
    If they are just flooring it, why do the brake lights come on?
     
  3. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,252
    Location:
    Silicon Valley
    #3 TEG, Jan 24, 2008
    Last edited: Jan 24, 2008
    People are asking that question in the TM blogs. Apparently the traction control does that automatically.

    I don't know why it still happens in the video where traction control is supposedly off.

    (Many types of traction control automatically apply the friction brakes to limit wheelspin. You could have the PEM limit motor torque itself, but then it wouldn't be able to manage slippage on individual wheels)
     
  4. WarpedOne

    WarpedOne Supreme Premier

    Joined:
    Aug 17, 2006
    Messages:
    2,659
    Location:
    Slovenia, Europe
    >> If they are just flooring it, why do the brake lights come on?

    Traction control kicking in. I guess it wants to say: "Watch out on me, I'm on the limit!"
     
  5. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,252
    Location:
    Silicon Valley
    Hmm. According to This Car & Driver article they say:
    "extremely quick-reacting traction control (which doesn't require brake intervention) because of the motor's ability to react instantly."
    So perhaps those brake lights are flickering just when the PEM decides to restrict torque due to detected wheel slippage?
    Without a limited slip differential I guess that means that you are acceleration limited by the (rear) wheel with the least traction. Some other systems might let you accelerate quicker with one wheel on ice and the other on gravel. (I am probably oversimplifying the whole situation though)
     
  6. AGR

    AGR Member

    Joined:
    Jun 21, 2007
    Messages:
    202
    The brake lights should not be coming on with the traction control activated. There is something not working correctly if the brake lights are activated when the tration control engages. Traction control is not related to braking.
     
  7. doug

    doug Administrator / Head Moderator

    Joined:
    Nov 28, 2006
    Messages:
    15,914
    Location:
    Stanford, California
    #7 doug, Jan 25, 2008
    Last edited: Jan 25, 2008
    I'm not sure how the brake lights should react to the traction control, but they should come on when the deceleration is above a certain threshold do to regen.
     
  8. siry

    siry Member

    Joined:
    Apr 5, 2007
    Messages:
    136
    Location:
    San Francisco, CA
    It's a bug - it shouldn't happen in that situation regardless of TC on or off. It has been fixed. Some new vids are being posted now.
     
  9. siry

    siry Member

    Joined:
    Apr 5, 2007
    Messages:
    136
    Location:
    San Francisco, CA
    The culprit has been identified - an overly sensitive brake pedal switch that was being activated by vibration.
     
  10. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,252
    Location:
    Silicon Valley
    Wow, QA via Youtube... What will they think of next!
     
  11. AGR

    AGR Member

    Joined:
    Jun 21, 2007
    Messages:
    202
    Can a Tesla match this....Click

    Or hang on to something like this....Click
     
  12. Albern

    Albern Member

    Joined:
    Dec 1, 2007
    Messages:
    217
    For what it's worth, this is probably the most exciting YouTube video of the Roadster that I've seen in a while.

    YouTube - VP9 burnout by Mark Vaughn

    Sorry, can anyone please tell me how to directly input YouTube videos?

    Alex B
     
  13. TEG

    TEG TMC Moderator

    Joined:
    Aug 20, 2006
    Messages:
    17,252
    Location:
    Silicon Valley
    #13 TEG, Jan 26, 2008
    Last edited by a moderator: Mar 13, 2016


    [y o u t u b e]http://www.youtube.com/watch?v=09LlCKufLtc[/ y o u t u b e]
    (without the spaces)

    Exciting as in - good thing the roadster didn't fishtail into that oncoming traffic!
    I don't think I would want to try that trick with a prototype. Having one wheel on wet, and one on dry could be risky under full acceleration. That driver probably owes his/her health to some firmware guys that did their homework.
     

Share This Page