Tesla Motors Inc. has selected BorgWarner Inc. for the production of a single-speed gearbox for the Tesla Roadster and is initiating a ramped-up production rate. So far, 27 customers have taken delivery of Roadsters.
Tesla engineers developed the specifications for the new gearbox and provided them to BorgWarner. The new gearbox is an integral part of an enhanced powertrain with significant performance and efficiency improvements. The new powertrain delivers about 30% higher motor torque on a single gear ratio, and it achieves a 10% higher EPA combined range.
“Last December, when the two-speed transmission designed by a previous supplier proved not to be durable, we announced we would modify our approach,” said JB Straubel, Chief Technology Officer of Tesla Motors. “By using a more powerful inverter and an enhanced motor design, we were able to implement a single-speed gearbox and still achieve our original performance goals. In fact, the new setup is superior in almost every way.”
The new gearbox is designed for the higher peak torque levels of the new Roadster powertrain, which has increased from 286 Newton-meters (211 foot-pounds) to 380 Newton-meters (280 foot-pounds). The new powertrain achieves an EPA combined range of 244 miles on a single charge, up from Tesla’s previously announced EPA range of 221 miles.
The Tesla Roadster is the only highway-capable production electric car of any kind for sale in the United States. With a 0 to 60 mph acceleration of 3.9 seconds, a 14,000 rpm redline, and the fastest top gear acceleration of any production car tested by Car & Driver magazine in 2007, the Tesla Roadster is unique in providing super car performance, zero emissions and extraordinary efficiency.
– from evworld