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New Launch Mode - firmware 2.9.40

Discussion in 'Model S: Driving Dynamics' started by patp, Dec 11, 2015.

  1. lolachampcar

    lolachampcar Well-Known Member

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    Hmmmm is polite when NO ONE ELSE (who actually paid for the car) has seen those results. Tesla stays quiet as their credibility circles the toilet.

    must have used a professional driver :)
     
  2. Bill D

    Bill D Member

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    My guess is that there's more unreleased software to come.
     
  3. stopcrazypp

    stopcrazypp Well-Known Member

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    Hopefully so. We already pretty much know the Motor Trend test car used software that was not yet released at the time of publication (it had launch mode when no one else had it yet).
     
  4. Bill D

    Bill D Member

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    MT probably used that grandmother from Jay Leno's Garage show that blew off his 427 Cobra :smile:
     
  5. fiksegts

    fiksegts Active Member

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    apparently they applied a 'correction' factor to the real world numbers to get their numbers, which is total BS for an electric car....

    the P90D Ludicrous does not run 10's, the car has been on the streets for months, Tesla really needs to address this....



     
  6. stopcrazypp

    stopcrazypp Well-Known Member

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    #306 stopcrazypp, Dec 29, 2015
    Last edited: Dec 29, 2015
    Reading their correction factor article, the correction factor here likely was zero or close to zero. For hybrids and turbo cars it seems the correction factor is minimal (they do not use the same formula as a naturally aspirated car which has significant engine power loss at higher elevations).

    Example 2004 Subaru WRX STi:
    No Correction: 13.5 @ 98.0 mph
    With Correction: 13.5 @ 98.1 mph
    http://www.motortrend.com/news/motor-trend-testing/
     
  7. AWDtsla

    AWDtsla Active Member

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    I'm still wondering if they applied their correction number to the weight. 250lbs lighter? Now we know it's not stripped down...
     
  8. lolachampcar

    lolachampcar Well-Known Member

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    Why are we left to speculate at all??? A 10.9 is simply that and it is tesla's responsibity to deliver it or explain why they can not. It is not our job to sit and guess about how a magazine working with tesla managed to repeat results still not seen by hundreds (???) of cars shipped to customers.

    I would also be surprised if tesla was not aware of these types of discussions. They have read TMC in the past and actively follow their own forum. They have reached out in the past when they cared to do so.
     
  9. fiksegts

    fiksegts Active Member

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    also depends on the weather and location of the test.... turbo cars certainly benefit from sea level and good weather.... and suffer when it's hot and at high altitude...


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    I agree, and it's not like we're hitting 11.0x 0 11.1x, we are pretty far off....

    I suppose I will have the best chance to get the best run possible run in a few weeks at PBIR, full charge, good track and conditions.... but I'm not expecting any 'magic', the vbox testing I've done is pretty clear.... the car needs a big increase in top end power to make a 10 second run...






     
  10. stopcrazypp

    stopcrazypp Well-Known Member

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    The specific test quoted for the Subaru was done at ~1100 ft above sea level judging from the stats posted. The correction was insignificant however.

    Wasn't the best run 11.2x after the launch mode, and 11.3x before? Getting closer but still a ways off. The trap speed Motor Trend supposedly got is the biggest difference however.
     
  11. AWDtsla

    AWDtsla Active Member

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    Depends on where on compressor map the car was previously running, and how much control authority the ECU has. Could be 0 benefit, could be more than an NA engine. Maybe the knock sensor's having a bad day too, who knows. But it isn't straightforward that's for sure.

    - - - Updated - - -

    I think it was less impressive if you take off the rounding. I couldn't get LC to do anything worth while, and it should be as simple as point and go. I even sidestepped the brake pedal, nothing...

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    BTW, I was running 2.9.68. Never bothered to check the actual version after it was updated.
     
  12. kennybobby

    kennybobby Member

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    MT = Motor Trend, or

    since they use 29.32 in-Hg as their pressure for STP, Standard Temperature and Pressure (sb 29.92), in their barometric correction factor = Moron Trend, or

    since they are subtracting 1-ft rollout and using a GPS-based measuring device instead of a real accelerometer = Math Tricks.

    Whateva sells the magazines...
     
  13. stopcrazypp

    stopcrazypp Well-Known Member

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    #313 stopcrazypp, Dec 29, 2015
    Last edited: Dec 29, 2015
    The SAE J1349 standard uses 99 kPA which is 29.32 in-HG at their 77F / 25C test temperature. They did not make any simple math errors.

    1-foot rollout is standard procedure for all the 1/4 mile times you see in car magazines because that figure is only relevant in relation to drag strips (where as explained above by others, all drag strips will have this factored in because of how staging beams work). Even Edmunds which insists on not using rollout for their 0-60 numbers, still uses it for the 1/4 mile number.

    As for GPS vs accelerometer, a GPS device actually is far more accurate for measuring distance and speed in this case than using an accelerometer because of calibration issues. That's why the vbox (a GPS based device) is one of the most popular devices used by magazines. Here's an article on why (and comparing different devices):
    http://www.caranddriver.com/features/do-inexpensive-performance-meters-work-feature
     
  14. kennybobby

    kennybobby Member

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    Oh yeah Vbox--uses Nautical miles in their calculation of horsepower for some strange reason...

    The SAE J1349 only applies to testing IC engines on a dyno, or properly instrumented IC engines on acceleration runs. The corrections are for air-fuel ratio compensation. Has nothing to do with performance testing of vehicles on a track, 0-60, 1/4 mile, etc. Get a copy and you will see that clearly stated.

    GPS is far more accurate than an accelerometer? i don't see how anyone can say that--just look at the frequency response. Accels are easily calibrated, how do you calibrate your GPS?
     
  15. AWDtsla

    AWDtsla Active Member

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    Vbox mini most people seem to have claims a resolution of 1cm. However the sample rate would seem to be a bigger problem, only 10Hz. So 33% to 50% of rollout time can be lost to aliasing? The second digit after the decimal point people post is basically garbage. At least when I use a gopro I get 60hz (or more).
     
  16. stopcrazypp

    stopcrazypp Well-Known Member

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    #316 stopcrazypp, Dec 29, 2015
    Last edited: Dec 29, 2015
    The whole horsepower formula is something people can input as a formula in vbox tools, but not what the vbox actually outputs from the data.
    https://racelogic.support/02VBOX_Motorsport/Performance_meters/VBOX__Sport/Knowledge_Base/Power,_Torque_and_RPM_Calculations

    They use nautical miles in that example likely because the vbox actually can use that as a unit:
    "Extra speed and distance units added – speed = ft/s Distance = Miles, KM & nautical miles"
    http://www.racelogic.co.uk/_downloads/history.php?file=_downloads/vbox/Updates/Software/VideoVBOX.hst&title=Video%20%20VBOX%20%20Setup&code=&version=v3.23.415&date=09/2014

    Motor Trend is aware of that, but they use that standard as a basis for their correction formula because they found that works out way better than the correction formula they were using previously. This is all detailed in the article I linked.

    My main point there is that they didn't assume STP and made a stupid math mistake as your comment was implying.
    http://www.motortrend.com/news/motor-trend-testing/

    Read the article I linked. The Vbox was by far the most accurate in terms of measuring 1/4 mile times and trap speeds when compared to what an actual drag strip timer measured.

    The problem with accelerometers exactly is the calibration needed. You need to do that every time you re-position the device inside the car or switch cars (if you want accurate results approaching that of the GPS device) and given it's almost impossible for a perfect calibration every time, the results are actually less accurate even when calibrated than a vbox which needs no calibration at all. This calibration issue is related to vehicle pitch during acceleration, not something a factory calibration can solve (unlike in other applications).

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    The vbox units used by car magazines have a 100hz sampling rate. They are $10k+ units, not the consumer models that cost less than $1k.
     
  17. P85DEE

    P85DEE Active Member

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    Agree with all of the above.
     
  18. Bill D

    Bill D Member

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    Am I the only P90DL owner that didn't yet get 2.9.40?

    I just returned from being away since thanksgiving. It was peacefully sitting in the garage on WiFi and I thought for sure the download would have shown up by now. Do I need to go ask for it at the Service Center?
     
  19. AWDtsla

    AWDtsla Active Member

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    I wouldn't get excited about it until someone produces real results with it, unless you're going to hit the dragstrip and try yourself.
     
  20. Branzo90D

    Branzo90D Salt and Pepper

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    Still no joy here either. I went as far as to e-mail Tesla support and ask for an OTA push, but they simply said "it looks like your software is up-to-date from our side."

    I'll get my tires rotated in a couple of months and ask them to push it at the SvC unless I get it OTA before then.
     

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