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100% electric Corvette hits 186 mph - world record

Discussion in 'Model S' started by ggnykk, Mar 8, 2016.

  1. ggnykk

    ggnykk Active Member

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    #1 ggnykk, Mar 8, 2016
    Last edited by a moderator: Mar 13, 2016
    About a month ago, I put up a thread at TMC suggesting to add a multi-gear transmission to improve Tesla car's overall performance. A lot of people said that it is a waste of effort and it was tried and failed before. Kind of surprised to hear this news that a small company called Genovation now beats Tesla for electric top speed world record, with a transmission! Share your thoughts.


    Youtube Video:




    Source: Dupont Registry (Electric Corvette Sets Land Speed Record)

    Battery powered cars and top speed racing are usually never referred to in the same sentence, but innovation in electric conversions is happening at a shocking pace. We heard rumors of an electric Corvette Z06 last year, but now it has been confirmed. In a press release last week, Autoblog announced that the Genovation GXE has set a new land speed record.
    Our friend Johnny Bohmer is a brilliant driver and holds numerous records. That’s why NASA allows him to use the Shuttle Landing Facility for high speed runs. The International Mile Racing Association (IMRA) was on hand to sanction the run, which resulted in a battery powered C6 Z06 reaching 186.8 mph.

    Power comes from a 44 kw/h battery pack that is rated to return a minimum range of 130 miles. This incredible range is made possible by using the Corvette’s factory six speed manual transmission in lieu of direct drive. Most electric cars ditch the transmission in favor of a fixed gear reduction. Genovation’s novel approach locates the electric motor in the same location as the V8. This provides a very low center of gravity, contributing to high speed stability.

    If you need the fastest street legal electric car, the GXE starts at $330,000. If your 1997 to 2013 Corvette could use a heart transplant, the conversion starts at $290,000. Considering that most new electric cars have up to 90 kw batteries, breaking the land speed record using only 44 kilowatts is nothing short of remarkable. This level of innovation will force the automakers to refine their designs at a faster pace. Stay tuned to Autofluence for all your land speed racing and electric car news.
     
  2. WarpedOne

    WarpedOne Supreme Premier

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    Say what?
    I stopped reading that smelly journalist pile of BS right there.
     
  3. ggnykk

    ggnykk Active Member

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    #3 ggnykk, Mar 8, 2016
    Last edited by a moderator: Mar 13, 2016
    In case you want to see the video without the background music. That Corvette definitely sound electric (as in with electric motor).

     
  4. brianman

    brianman Burrito Founder

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    A couple issues with the article:
    1. An editor really needs to pay attention to the units on battery capacity. Is it "kw/h" or "kw"? Neither. It's kWh.
    2. "Most new electric cars ... 90 kW". I'm not sure that's the case. Do we really think that the "new" 90 kWh Model S deliveries account for "most" of the global "new" electric car market? Even if you take just today's numbers? I suspect not.

    A surprise with the car:
    So Tesla delivers 4700 pound sedans that do 155mph with a single car to customers at "volume" -- not one-offs. How is that Corvette can put a 6 speed transmission in and only bump that number to 186mph? Feels like sandbagging to me.

    All that said. Gratz on the record, guys!
     
  5. skilly

    skilly Member

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    all that for the measly price of $355,000.00...
     
  6. daxz

    daxz Member

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  7. RAW84

    RAW84 Member

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    You quoted the wrong BS.

    A minimum range of 130 miles would, indeed, be INCREDIBLE. Of course there's no way that's the case.
     
  8. WarpedOne

    WarpedOne Supreme Premier

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    Good observation. That would indeed be an incredible feat featuring 44kWh battery.
     
  9. ggnykk

    ggnykk Active Member

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    yea, there are definitely some poor reporting from Dupont Registry, that's the news reporter's fault. Doesn't quite dis-credit what Genovation has achieved.

    Between the top speed of 155 mph and 186 mph, the extra power required is a lot more than the extra 31 mph may suggests. Aerodynamics drag increase exponentially, not linear.
     
  10. Max*

    Max* Autopilot != Autonomous

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    Huh? The Model S 40kwh had a rated range of 160 miles (IIRC), so why would 44kwh and 130 miles be incredible? :confused:

    - - - Updated - - -

    One more thing, Tesla limited the top speed to 155mph. No one knows what the true top speed of the car is. Does it spontaneously combust at 156mph? 157mph? etc. Take off the limiter, and let's see what the real top speed is.
     
  11. MichFin

    MichFin Member

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    I think adding a transmission only adds complexity to a car that is already fast enough.
     
  12. SabrToothSqrl

    SabrToothSqrl Active Member

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    155 is the general speed limited number for most performance cars that aren't super cars... I think it had more to do with that than limits of the hardware.

    the car can drive all legal speeds, and nearly 100 mph more than that, and 0-60 very, very fast. A transmission just isn't... needed. it's a compensating piece of tech that no longer has a function in a EV.
     
  13. McRat

    McRat Active Member

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    186 in the standing mile is nothing to sneeze at. You don't hit top speed in a mile.

    Very few cars are that fast. Sure there are many that go over 200 now, but 186 in a mile is faster than a ZR1 by a little.
     
  14. Max*

    Max* Autopilot != Autonomous

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    Ah, didn't realize that's in a mile...
     
  15. MP3Mike

    MP3Mike Active Member

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    I wonder how long it can maintain that 186 MPH. We know that a Model S can't maintain the 155 MPH for very long... (Though I can't remember if someone has said how long it can.)
     
  16. tga

    tga Active Member

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    155mph ~= 250 km/hr. Most European manufactures (except Porsche) have a "gentleman's agreement" to adopt a voluntary 250km/hr limit, to avoid a top speed arms race that would result in governments mandating a (possibly lower) top speed. Porsche gets away with no limit, well, because they're Porsche. :)

    In this case, it appears the transmission is necessary to hit that speed, because the RPM limit on the motor is relatively low (10,000 rpm):
    700hp Electric Corvette Coming - Page 2 - DIY Electric Car Forums

    I didn't look to hard for specs on the EV drivetrain, but if it would be discussed anywhere, it would be on that site (diyelectriccar.com)
     
  17. sorka

    sorka Active Member

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    Adding a second gear to the MS could increase it's top speed past 155 MPH for sure but it wouldn't be able to hold it very long due to battery heating.

    But adding the complexity of a gear box would hurt performance below 100 MPH since the MS's KW output is parallel to it's rear wheel hp up to that speed. It starts to dip after 100 MPH and becomes more noticeable around 115 MPH. I don't have data beyond that speed as the vbox data and REST data I have at those speeds is limited to a few 1/4 mile runs.
     
  18. SomeJoe7777

    SomeJoe7777 Marginally-Known Member

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    Telsa's small drive units have a rated RPM limit of 18,000 RPM. With a 9.73:1 gear ratio and stock tires that are 751 rev/mile, the motor hits 18,000 RPM at 147.8 MPH.

    155 MPH overrevs the motor by about 5% from it's rated speed.

    Top speed is difficult to achieve with electric motors without the transmission. In addition to physical limits on rotor RPM and centripetal force, high RPM increases the necessary applied frequency from the inverter, and the inductive reactance of the motor goes up with the frequency. To put more current through the motor under high inductive reactance conditions needs more voltage, but you're limited by what the battery can put out. Especially at that condition when the voltage is already sagging from the current draw. Internal motor losses like hysteresis loss go up with frequency also, so you run into a loss of efficiency and a cooling issue at high RPM.

    The disadvantage with that Corvette is that the motor's torque has to be limited to what the transmission can handle. The 0-60 times are not likely to be that impressive. They also lose efficiency with the transmission, both in internal friction and a huge hit in amount of regen it can utilize. Without optimally downshifting in a controlled pattern, you lose a ton of energy in the friction brakes.

    As well, they saved a lot of weight using only a 44 kWh battery at the expense of range of course.

    It's a purpose-built car for getting a top speed run, but completely impractical as an actual useful street vehicle.
     
  19. MP3Mike

    MP3Mike Active Member

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    Is that for the front or rear drive unit? (I thought they used a different gearing ratio between the front and rear drive units.)
     
  20. ICUDoc

    ICUDoc Member

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    All well and good for a one-off geared electric car to take that record. The extra gearbox weight and complexity makes it a liability in a car like the Model S. Not an asset at all. Who the heck wants to do top speed runs anyway? That's not what the Tesla is for.
    Poor reporting that misses the point which is: this geared EV holds the top speed record. Comparisons are pointless, unhelpful, perhaps even harmful.
     

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