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Factory Plus versus Field Upgrade

Discussion in 'Model S: Driving Dynamics' started by lolachampcar, Jul 21, 2013.

  1. lolachampcar

    lolachampcar Active Member

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    I just received my P85+ having sold my previous P85. I'm a M5 fan so I tend to like a firmer ride and much more feedback from the road.
    I had several conversations with both Tesla Engineering and other knowledgable people in the suspension design community prior to the + package coming out as I was absolutely certain I had "firm up" the rear of my P85. Once the Plus package was announced, that education process turned to deciding on the path; do I retro fit my car or go for the production Plus?

    Obviously, I took the advice of Tesla Engineering and went the factory Plus path. I am VERY happy I took that course but then my tastes tend to deviate from the norm. That very idea got me thinking.


    If I were not so far to the handling and feel side I think the retro fit option would have been perfect provided it was implimented in a certain way.


    I would start by installing all the + rear suspension arms (lower a-arm, upper link, torque link and toe link).

    If you have 21s like I did, I would change to Pilots.

    If you do not and prefer a smoother ride, I would simply leave the tires alone.

    I would not go for the mandatory staggered size tires and wheels. They do provide some oversteer margin but, in my case, I am comfortable without that added margin. If you find you are not, you could always make the decision to purchase Teslas package or aftermarket wheels/tires with a similar stagger in width.

    I would not be concerned about the shocks or the sway bars. The production + damping has been stiffened but I do not think this is core to improving MS' handling and you do pay a penalty in ride comfort. Both the benifit and penalty are small but they are real. This is a comment purly from my gut as I have not driven the exact same car back to back with and without the damper modifications. In short, it is a feeling and not an absolute.

    I feel the same about the sway bars but even stronger about the negative impact they have on ride quality. One of the engineers I spoke with (Tesla, I believe) went into great detail on how sway bars transfer road irregularities from one wheel across the car to the other. This became abundantly clear to me on my drive this morning when I went across a small construction zone. The car yanks from side to side in a rocking fashion when one of the front wheels has to deal with a pot hole or other imperfection at low speed. The engineer called it head snatch and I see why. Again, I prefer a stiff car and I am perfectly happy with this side affect. For most, I think you will find it the single most imposing element of the + package (or at least second to road noise).



    That is my 2 cents worth and a lot of the above is based on gut feeling only so please consider it simply one person's opinion.
     
  2. HHHH

    HHHH Member

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    congrats on your delivery and thanks for the write up. Coming from owning high performance sports cars (M5's & 911 turbo's) I'm glad I ordered the P85+ based on your insights. I had a 2014 911 turbo S on order so I was hoping to miss that as little as possible. I know it's a completely different car, but I'm happy with my decision. I'm looking forward to getting my car in about a week or so, I can't wait!
     
  3. JPP

    JPP Active Member

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    I was at the Fremont SC yesterday (...yes, Saturday) to pick up my car after a service visit for a number of small issues, including an alignment to fix the slightly out-of-midline steering wheel. I happened to chat with a senior service tech there who is their alignment/suspension guru, and he shared a few notes/observations with me. Since the Fremont SC is attached to the factory, they are asked to do projects more related to testing and production in addition to their huge service load. The senior tech I spoke to has worked on a couple of 'test' cars to do the P85 to P85+ modification/upgrade, to see what training/documentation is needed, if the parts/fitment are sound, and how long it will take. It takes over 20 hours of tech time to do the full upgrade, thus the big $$ cost. Interestingly, the Fremont SC has 5 Model S owners signed up ready, willing & able to do the upgrade (regardless of $$). 2 are original Signature owners with the sig red, and do not want to give their cars up in trade. If you haven't ordered your P85 yet, and are on the fence about getting the P85+, take heed of lolachampcar's observations and the time and $$ for a retrofit.
     
  4. HHHH

    HHHH Member

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    That sounds familiar
     
  5. pilotSteve

    pilotSteve Member

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    @lola - do you think the retrofit rear suspensions parts you suggest (from the factory field upgrade kit) are compatible with a non-Perf (standard Sig in my case)? And do you think it would be beneficial here as well?

    I had a blast at a ProDrive course at PIR last week and would like to improve handling so this is something I'd likely do if its makes sense.

    btw on the track (as I'm sure you know) we are power limited after about 10 minutes (4-5 laps usually) anyhow so its all about the HANDLING so lines can be precisely driven and what ever available power applied to the road in the most efficient manner. To me that means suspension upgrade is more important the the extra horsepower of the Perf.
     
  6. lolachampcar

    lolachampcar Active Member

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    I would not attach the improved rear suspension with the power of the performance package. I would think it would work just the same on an S85 as on a P85 (not counting the 21s which were standard on all the early P cars).
     
  7. pilotSteve

    pilotSteve Member

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    thanks! That is what I'd hoped for. I'll wait for Tesla to make the kit available. (Still wish your DIY arms etc. had worked out, that would have been fun to install. Ah well.)
     
  8. darthvdr

    darthvdr Member

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    I am by no means a driving critic or even close to someone who should even speak on the handling aspects of the +, but I am very glad I did. My only criticism is that the seats do not provide enough bolstering support when I make hard turns.
     
  9. lolachampcar

    lolachampcar Active Member

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    darth,
    I was ok with my P85 but gotta agree with you on the P85+. The stiffer more responsive car throws me in the seat more and a good bolster would help that. That being said, I much prefer the car as is then going back to my P85.
     
  10. HHHH

    HHHH Member

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    lola, with you having owned both it makes me a feel a hell of a lot better that I went with the P85+. I would have gone with it regardless, seeing as my next car was another sports car anyway, but I'm glad that I got the inside scoop from someone who knows their stuff and has literally owned both.
     
  11. jammerdjc

    jammerdjc S Owner/Member

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    +1

    Thanks for the great write-up.
     
  12. crazybrit

    crazybrit Member

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    How much does the upgrade cost, if done at a service center?
     
  13. logan

    logan Member

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    $15,000 + tax, as per Tesla San Diego.
     
  14. lolachampcar

    lolachampcar Active Member

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    Note that all new cars are being built with the stiffer bushing lower a-arms.
    My P+ is now on coil springs with Standard air ride heights and using standard air dampers (more bump and rebound than coil dampers). It is getting a lot closer to a M5 in feel without all the harshness. MS is one stiff platform.
     
  15. brianman

    brianman Burrito Founder

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    There are two flavors: full and partial. Full is $25k. Partial is $15k.
     

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