Tesla reveals details of 'powertrain 1.5' update

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Tesla reveals details of 'powertrain 1.5' update

Tesla reveals details of 'powertrain 1.5' update

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Tesla's problems with the gearbox and drivetrain of its early models is well-known, and early buyers of the car were assured they would get updated internals installed free of charge as soon as they were ready. That update is known internally at Tesla as 'powertrain 1.5', and the company announced yesterday that steady progress is being made, outlining what will and will not be included.

The powertrain 1.5 package is essentially a reworked engine and gearbox, designed to fully handle all of the torque available with greater durability and more power output. The current Tesla two-speed drivetrain is effectively locked into second gear all the time in order to withstand the forces being transmitted through the gearbox. This update fixes that problem with a new single-speed gearbox, but also adds several updates.

A new power inverter (PEM) to deliver more current, a more powerful motor and a new motor-to-gearbox coupler mate with new firmware (computer programming) to yield significantly improved performance over the 1.0 drivetrain. In an update on the official website, Tesla's Chief Technical Officer JB Straubel writes that the car is cutting quarter mile times "in the 12.9 second range" and producing over 45% more torque at the wheels than the previous incarnation. Most of the increase comes from the more powerful motor, but 12% of the boost is derived from the new gear ratio.

Straubel is keen to point out that no changes to the battery pack have been made, and none were needed because total current draw and peak current draw (how much power the motor uses) were intentionally made the same as before. A complex interaction of the PEM and motor allow the one-speed drivetrain to function as though it had an electronic transmission with more gears, by stepping up current while dialing back voltage, allowing power levels to remain the same.

A powertrain 1.5-equipped car is already undergoing regular testing, and more is planned before it will be offered to customers. Two test cars, one running in Death Valley, California for hot weather testing and another doing a 40,000km (25,000mi) durability test on a closed test circuit, will help Tesla get the revised system ready for real-world use.

No timeline for its release comes with the new information, but several more months of testing are already on the table, so it will not likely be ready for mass consumption until Q4 2008 or later.

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Comments (4)
  1. Still havent delivered a car, and yet people are still throwing money at them.

    Unbelievable. Fools and their money are soon parted. - and who the hell thinks that an electric sportscar is some kind of environmental solution? Some dork cruising the beach or speeding around is solving energy problems how?

    try building an alternative powertrain for diesel spewing big-rig trucks that fill the highways and log millions of miles. That would be progress.


  2. so... instead of locking it into second gear and using the entire vehicle as designed (with exception to disabling the 1st gear), they're offering an update but in the same idea. one gear (different ratio?) and new motor?

    I don't mean to bash them for doing something that is really unique, but you mean to tell me that you cant design a gear box that can handle that kind of torque? who cares if you have to use the gear box out of a heavy duty truck. just find something and fit the damned thing. its going to weigh a lot but at least it will work. give you time to put out a decent car, that meets all of your objectives.

  3. Considering the size and weight of the Tesla roadster, if the power from the electric motor(s) is transmitted to the wheels via differential, it is probable that a gearbox with speeds, etc is not going to be appropriate to handle the massive torques that electric motors usually deliver. Perhaps using a continuoulsly variable transmission (no changing gears) would be better. The alternative that uses electric motors operating at constant power is the same as that diesel electric and electric locomotives have used since 1920 or so. That method has proved to work for trains since. However, I don't think it requires transmissions or gearboxes...

  4. I'm still waiting to see if I can go visit the dealership...

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