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Drivetrain 1.0, 1.5, 2.0... Specs? Plans?

Discussion in 'Roadster: Technical' started by TEG, Aug 24, 2008.

  1. TEG

    TEG TMC Moderator

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    So we know that "Drivetrain 1.0" was really just a development drivetrain used in the prototypes and some of the first production cars with a planned retrofit to 1.5 ASAP. I think once Drivetrain 1.5 is finalized, they would probably just get rid of all the 1.0 components and relegate it to a footnote in the history books.

    The main way I think to describe 1.0 is 185kW, 640amps, 13,000RPM redline, 248hp max.

    1.5 is currently slated for all production roadsters, and as far as I know there have not been any problems or delays so anything made in 2009 would likely have 1.5 and previously built cars would get retrofitted soon afterwards. I think I recall that they said they would let some early customers keep 1.0 (locked in 2nd gear) if they didn't care about the performance difference. Keeping an inventory of 2 different kinds of drivetrain components on hand probably isn't ideal, so I wonder if they would "insist" that everything someday get upgraded to 1.5?
    The specs for 1.5 don't seem to be 100% official yet.
    We heard stuff like "we have been able to boost the PEM output current by about 33% from 640A rms to 850A rms" and "The motor torque is improved by a bit more than 30 percent beyond what was already great and the ¼ mile time for the car is now in the 12.9 second range." and "The combination of less heat generation and the new gearbox is expected to improve the range of the car by about 10 miles"
    If we take the above and just add 30% to 1.0 specs we get something like 240kW, 850amps, 14,000RPM redline, 320hp max. Lately there have been some mumblings that 320hp may be too much. Perhaps the 30% torque boost isn't viable at higher RPMs and so max HP isn't so high. Anyways, time will tell.

    As far as I know, Drivetrain 2.0 is for Model S, and I recall they were possibly considering water cooling for the eMotor, and a single speed gearbox, but I don't know much else.
     
  2. Joseph

    Joseph Member

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    Elon said that the battery pack in Whitestar (drivetrain 2.0) is a big improvement over the Roadster.
     
  3. vfx

    vfx Well-Known Member

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    Adding to.

    There are two reduction gear box versions in the works. EPA testing is being done on both.

    I highly doubt that they would let any old 1.0 gearboxes stay in the cars. There are probably some owners who are content to wait for the update deferring to those who want it done ASAP.

    I thought version 1.5 was going to max at 13,500
     
  4. TEG

    TEG TMC Moderator

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    #4 TEG, Aug 24, 2008
    Last edited: Aug 24, 2008
    Maybe, although here, they said "...we have designed this transmission to have a long life at a much higher input torque (400 Nm) and higher speed (14,000 rpm)."

    But they also say "...Before thermal limit the 1.5 powertrain will have an extra ~33% from the motor..."
    So, the big question is what does "thermal limit" limit? Possibly max HP, and perhaps reduces redline a bit from the design target.

    Now this part I find a bit confusing "...Although this improved powertrain will have ~45% better torque at the wheels it will not have a significantly higher peak power output and it will not have a higher peak battery current draw. (The two are directly related by the efficiency of the PEM, motor and transmission) Our goal has actually been to keep the peak battery current at the same level (about 650A)...."

    Contrast that to what was said earlier: "we have been able to boost the PEM output current by about 33% from 640A rms to 850A rms"

    So are they saying that they "can" get PEM to 850A, but their "goal" is to only out 650A?

    I guess I can't quite figure out exactly how the new PEM will be better than the old.
    If max AMPs is basically unchanged, and max HP is similar, then where is the benefit? Just more torque at lower RPMs?
    If the low RPM torque is higher, but max HP is relatively unchanged, then I guess it must mean that the torque peak starts to drop off sooner (lower RPMs), *or* it drops off at a much steeper slope compared to DT 1.0.
     
  5. WarpedOne

    WarpedOne Supreme Premier

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    There is no need to keep inventory for 1.0. They can just wait with replacement until something specific to 1.0 brakes down and then replace the whole DT.
     
  6. vfx

    vfx Well-Known Member

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    They might have just changed their minds. The technology might have forced them to, or the priorities (cost, marketing, handling etc.) might have shifted.

    Remember the Whitestar was a series hybrid for a while.
     
  7. Joseph

    Joseph Member

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    TEG,

    The difference between the 640 amps quote and the 840 amps quote is that the first is talking about input (how much the controller draws from the battery) whereas the 840 amps quote is talking about the output. A controller, the so-called PEM, may, for example, draw 100 amps at 400 volts (40kw) and then spit out 400 amps at 100 volts. (This assumes 100% efficiency, of course) More amps equals more torque and more volts equals more rpm. A controller can spit out more amps, but less volts, or more volts but less amps. So you either got more torque or more rpm but not both, because if you got more of both, then you'd have a perpetual energy device. This is why they can get more torque, but not more horsepower.

    I have a note to make about this though. This is how I understand this works for DC motors. In an AC motor, amps might not so neatly equal more torque, and more volts might not so neatly equal more rpms. It can't be that different though....right? Anyone know? If not, I can always post a question on the EVDL.
     
  8. TEG

    TEG TMC Moderator

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  9. dpeilow

    dpeilow Moderator

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    I think that is an old document that was in the public domain before the 1.5 spec settled down (a bit like that BIMS information board I saw last summer).
     
  10. TEG

    TEG TMC Moderator

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    Wouldn't you think they would update it then? People put down money based on expected specs.

    Also, since 1.5 has "settled down" (and is in production) why doesn't Tesla publish an actual max HP figure now?

    Could it be that the 2009 models will actually have more power than 2008 models but they don't want to say until all the 2008s are delivered?
     
  11. dpeilow

    dpeilow Moderator

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    I'm not sure why the news on specs has been so sparse, I'm just saying that a little bird told me that the eventual 1.5 max bhp didn't increase by much, just the torque.

    I'm sure there will be incremental improvements to the car (e.g. the 0-60 in 3.7 that was mentioned), but I bet the 2008 owners are happy (I'd still have one if I had the cash :biggrin:).
     
  12. graham

    graham Active Member

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    Or release their range numbers to the EPA?

    Interesting thought. I bet many 2008s would be happy to pay for the upgrade (assuming it was offered) I dunno if there are any efficiencies with getting extra money and upgrading before delivery...
     
  13. Joseph

    Joseph Member

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    dpeilow,

    This whole issue was mentioned a while back. I thought you found out that the poster at the British International Motor Show, saying "300+ bhp" was wrong.
     
  14. vfx

    vfx Well-Known Member

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    Or braking stats. (R&T's does not count)
     
  15. TEG

    TEG TMC Moderator

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    The BIMS banner was one thing, but then I found that 'Ferdinand' spec sheet too... And it hasn't been updated or removed.
    2739103184_262489838b.jpg

    3166379100_80d5084cec_o.jpg
     
  16. Cobos

    Cobos S60 owner since 2013

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    And that Ferdinand Motors spec sheet is something given them from Tesla I'm pretty sure about. The Tesla Roadsters sold in Norway are sold on that spec. Could this be something with the UK calling it BRAKEhorsepower while the US calls it just horsepower. Are these the same horses?

    Cobos
     
  17. dpeilow

    dpeilow Moderator

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    #17 dpeilow, Jan 4, 2009
    Last edited: Jan 4, 2009
    Yes I was told by a reliable source several months ago that the BIMS poster was wrong - based on a false assumption that as the torque had increased then the power increased proportionately. As Joseph says, I've posted that a couple of times before.

    As I understand it, both bhp and the US hp do not take into account drivetrain losses, so they are (virtually) equivalent. Indeed, if you look at the ratios between hp and kW of the US specs (248/185) and the BIMS poster (300/225) they are almost the same.

    So I can't say why the Ferdinand datasheet shows 225kW, but as it appeared around the same time as the BIMS poster, it could just be the same error. Maybe Cobos could ask the dealer about this?
     
  18. GSP

    GSP Member

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    Brake horsepower is measured at the flywheel with a "brake" (dynamometer). The word "brake" distinguishes it from "indicated horsepower" (power developed in the cylinders) and "friction horsepower (power lost to friction in the piston rings, crankshaft bearings, oil pump, camshaft etc.)

    BHP = IHP - FHP.

    In the US we usually less formal (some would say less educated :rolleyes:) and just say "horsepower." However it is still often abbreviated "bhp."

    For ICEs we usually use SAE (Society of Automotive Engineers) procedures to measure bhp for ICEs. In Europe the DIN procedure is usually used. The difference is usually just a few horsepower (about 1%).

    I don't know what procedures are used to measure bhp for electric motors. It's possible that US and Europe have different procedures here also.

    However, Tesla doesn't seem to be very good at keeping their published specs up to date, and that is most likely what is going on here.

    GSP
     
  19. TEG

    TEG TMC Moderator

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  20. GSP

    GSP Member

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    Arrrrrrg. MORE bad data. :mad:

    Or, maybe the European Roadsters will be built with drivetrain 2.0? :wink:

    GSP
     

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