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Improvement to P85 acceleration

Discussion in 'Model S: Driving Dynamics' started by MartinAustin, Jul 12, 2015.

  1. MartinAustin

    MartinAustin Active Member

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    Anyone remember this tweet? Has anyone ever noticed an improvement or read anything about updates to the regular P85 ?

    p85tweet.png
     
  2. sorka

    sorka Active Member

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    I don't know if I've noticed an improvement but I haven't had any difficulty getting 3.1 seconds with a 1 ft rollout with a 90% charge. Almost no manufacturer actually meets their 0-60 specs unless a professional race car driver tries multiple times to get one good launch. As far as I'm concerned Tesla has over delivered on their 0-60 promise.
     
  3. supratachophobia

    supratachophobia Active Member

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    I think this one is just going to fall by the wayside honestly. Not sure where the improvement could come from since traction is a big factor in the RWD models. I think it was said that 0-42mph it's traction, and 42-70mph it's battery/drivetrain?
     
  4. MartinAustin

    MartinAustin Active Member

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    My casual tests in my P85 in December 2013 indicated 4.19 seconds 0-60 with no rollout (I do not know the definition of the rollout is).

    That was enough for me to conclude that it meets or exceeds the manufacturer's claim. No launch mode required, no special tires or whatever. Just floor it as hard as you can :)

    Was just wondering if the 2nd tweet Elon put out had been implemented.
     
  5. sorka

    sorka Active Member

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    With the 1 ft rollout, the time doesn't start until the car has moved 1 ft. It removes human reaction time from the equation and is the standard by which 0-60 times are published.
     
  6. rainman50

    rainman50 Member

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    The thing that I don't like about the 1ft rollout is that it if a car has excessive reaction time to when it moves the car once the throttle is pressed. Example would be a turbo. Some of them have a decent amount of lag which to me should add to the 0 to 60 time. The Tesla have very little if any lag.
     
  7. sorka

    sorka Active Member

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    You can dislike it all you like. That's the standard by which 0-60 times are tested and published. A car with a turbo lag will take longer to get to 60 regardless of whether you include the 1 ft rollout or not. The Tesla has no lag, not very little, and it's the reason why it beats almost everything to 60 whether you include a 1 foot rollout or not.
     
  8. Niclas

    Niclas Member

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    Did the original spec 0-60 times for P85 include 1-foot rollout or was it from standstill? What is the actual difference between P85 and P85D times measured by the same standard?
     
  9. AmpedRealtor

    AmpedRealtor Active Member

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    I believe Motor Trend's 3.9 second time for the P85 was with a 1-foot rollout.
     
  10. sorka

    sorka Active Member

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    A manufacturer would be committing competitive suicide by not using the 1 ft rollout since everyone else does.
     
  11. Niclas

    Niclas Member

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    #11 Niclas, Jul 14, 2015
    Last edited: Jul 14, 2015
    But Teslas original spec time for P85 was 4.2s wasn't it? And motortrend tested it at 3.9s. Why would they underrate the performance? That is competetive suicide more than anything. Most other manufacturers overrate their 0-60 times (at least under not ideal conditions with pro driver).

    reading the P85D vd GTR-thread, the conclusion was that Tesla did not use 1-foot rollout before P85D, meaning the P85 time at 4.2s is from standstill. The difference between standstill and 1-foot rollout is around .3 s so that will give the P85 a 0-60 time of 3.9, exacly as tested by motortrend.

    In conclusion, the difference between P85 and P85D is .7 s (3.9 vs 3.2).
     
  12. sorka

    sorka Active Member

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    The also underrated the actual hp by a lot too. The P85 consistently rated at 416 hp but dynos 430. Assuming a small 5% drivetrain loss(most rear wheel drive cars are 15% with a transmission and driveshaft) that makes 450+ at the motor shaft. The S85 dynos at 375 rear wheel hp but is only speced at 362. So that makes it's real hp closer to 400.

    The P85D on the other hand......
     
  13. Niclas

    Niclas Member

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    Yes the P85 was initially rated at 416 hp, but was later changed to 470 in the design studio when P85D was released. You can also see on the CPO website that Tesla now rates P85 at 470 hp. This figure corresponds well to the dynos.
    Maybe the S85 was also underrated.
    It is really strange that Tesla overrated the P85Ds hp by so much.

    - - - Updated - - -

    Comparing P85 vs 85D using same methods:

    85D 422 hp 0-60 4.4s
    P85 470 hp 0-60 3.9s

    P85 0.5 s faster, quite a bit. Almost 50hp more.
     
  14. Alysashley79

    Alysashley79 Member

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    IMO I think they already did tweak it it was just done quietly I can't remember which iteration of the software update it was somewhere in6.2 though I noticed not when flooring it off the takeoff but later say around 30mph if I floor it to overtake I get a little burnout where I never used to. I asked the SC about this and they just smiled and said no comment. Also to note all 4 of my tires are at 7/32 so no this is not lack of tread.

    Also to note when I took delivery of my car we took it to the track and it was pulling 4.1 with 19" primacys and now consistly pulls 3.9 with the same size and brand of tires.
     
  15. sorka

    sorka Active Member

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    470 is certainly inline with what it dynos. That would put power train loss at 7.2% which is still way more efficient than a rear wheel drive ICE.
     
  16. LetsGoFast

    LetsGoFast Active Member

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    Actually, many European brands quote 0-60 times without rollout. Its really not something obsessed about as much anywhere outside the US. As you note, it is extremely rare for mere mortals to actual achieve quoted 0-60 times on most performance cars anyhow, except a few cars with very precise launch control software. If you look at the BMW M3 0-60 times, you'll see articles claiming a range of nearly a full second. Some of that is based on rollout/no rollout, but more of it is due to the difficulty of pushing the car to its peak (drivers are understandably reluctant to drop the clutch at high rpm, tires need to have optimal grip conditions, etc).
     
  17. sorka

    sorka Active Member

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    Even with precise launch control cars often don't come close to their 0-60 claims. The planets and stars have to align just right.
     
  18. supratachophobia

    supratachophobia Active Member

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    Extremely interesting. I too have noticed the chirp at 30mph but wrote it off as worn tires....
     

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