Posts Tagged ‘tesla’

TESLA version 2.0 hits the road?

Saturday, September 13th, 2008

tesla_roadster.jpg

Tesla Motors has released the much-awaited upgrade to the gearbox in the all-electric Roadster, and in typical Silicon Valley fashion calls it Powertrain 1.5 — even though it’s a different transmission and so ought to be called v2.0.

Nomenclature aside, the slick one-speed Borg-Warner transmission joins a stouter power inverter and revised engine in a package said to deliver 30 percent more torque and 10 percent more range. That lets the Roadster make good on its promised zero to 60 time of 4.0 seconds while squeezing 244 miles from the battery. “The new setup is superior in almost every way,” says J.B. Straubel, Tesla’s chief technology officer.

Tesla says it’s already putting Powertrain 2.0, er, 1.5, in Roadsters that have made the trip from the factory in Hethel, England to San Carlos, California, for final assembly. So what’s different about Powertrain 1.5, and what happens to the 27 people driving Roadsters with Powertrain 1.0?

The new one-speed transmission weighs 17 pounds less and creates less drag on the motor, increasing efficiency and bumping the car’s range. A revised power inverter puts out 850 amps, up from 650, and the motor had redesigned terminals to reduce resistance. It’s beefier, too, and torque rises from 211 foot-pounds to 280.

Tesla started developing Powertrain 1.5 after realizing the two-speed transmission it planned to use “had many durability, efficiency and cost challenges,” Straubel wrote on the Tesla blog. Eager to start building cars, Tesla slapped an interim one-speed transmission in the Roadster when it fired up the assembly line at the Lotus plant in Hethel, and although early reviews of those cars were positive, the stop-gap tranny significantly cut into its performance. Early adopters got a car that did zero to 60 in 5.7 seconds — about as fast as the Toyota Tundra pickup. Powertrain 1.5 cuts that to the promised 4.0 seconds, putting the Roadster on par with the Porsche 911 GT3.

Tesla’s put 27 Roadsters in driveways since production started March 17, and will retrofit every one with the new drivetrain at no charge beginning next month. Darryl Siry, vice president of sales and marketing, tells us the modular design of the Roadster’s drivetrain makes it a plug-and-play operation. “It’s a four-hour swap,” he says. “It’s not a complicated thing.”

With the drivetrain finally sorted out and the assembly line running smoothly, Tesla’s increased production from four cars a week to 10. That’s expected to double before the end of the year, then double again to 40 a week early in 2009.

“Now that we have a final powertrain design, in a matter of months there will be hundreds of Tesla Roadsters across the country,” says CEO Ze’ev Drori. “We’re heralding nothing less than a new era of the automobile.”

But what about that nomenclature? Siry says Powertrain 1.0 was the internal designation for the air-cooled motor in the Roadster, while Powertrain 2.0 refers to the liquid-cooled motor being developed for the all-electric sedan that was codenamed Whitestar (the Roadster was Blackstar) but is now called Model S.

Glad that’s cleared up.

Photo by Tesla Motors.
source: wired