Tesla ends development of Drivetrain 1.5, ready to ramp up production
The Tesla Roadster launch has been anything but silky-smooth, but the upstart EV automaker hopes its problems are in the rear view mirror with the completion of Drivetrain 1.5, which includes an upgraded electric motor and swapping the original two-speed automatic transmission for a Borg Warner-sourced one speed. The changes will improve the Tesla Roadster's instant torque from 211 to 280 lb-ft while also improving its range by 10% to a shockingly impressive 244 miles.
Drivetrain 1.5 also means Tesla can finally ramp up production of its well-publicized roadster. Within the next few weeks, Tesla will begin producing 10 Roadsters per week. By next March, that number will increase to 40 samples per week, which will go a long way toward satisfying demand for the sexy EV. The new, upgraded Drivetrain 1.5 is so much better than the mechanicals it replaces, Tesla will keeps its promise and retrofit the 38 models already produced and delivered with the new equipment. Hit the jump to view Tesla's official press release.
Gallery: First Drive: Tesla Roadster
[Source: Autoblog Green]
PRESS RELEASE
Tesla Motors Selects BorgWarner for Production of New Gearbox for Tesla Roadster
Deliveries of 27 Roadsters Completed to Date, Production and Delivery of Roadsters To Accelerate With Final Powertrain Solution
SAN CARLOS, Calif.--(BUSINESS WIRE)--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.
Production of Tesla Roadsters began in March, and the first vehicles were built with an interim transmission design. Customers who own Roadsters with the interim transmission can have their powertrain upgraded free of charge.
Tesla Motors starts production of 10 new Roadsters each week. Customers typically take delivery four to six weeks after production begins. The company expects production starts to ramp up to at least 20 vehicles per week within a few months and 40 per week by early 2009.
"Successfully implementing the new gearbox in less than a year was an incredible technical challenge and huge accomplishment for Tesla's engineers," said Ze'ev Drori, Chief Executive Officer of Tesla Motors. "Now that we have a final powertrain design, in a matter of months there will be hundreds of Tesla Roadsters across the country. We're heralding nothing less than a new era of the automobile."
Reader Comments (Page 1 of 2)
jjpg2000 4:13PM (9/10/2008)
Woot that's awesome news!
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McLovin 4:13PM (9/10/2008)
Mark my words ... this car is the future of speed.
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Artie Lange 5:20PM (9/10/2008)
It may be the car of the future, but I hope its not the future of speed. A future of speed without the sound of internal combustion would be a very boring one.
Cory 5:52PM (9/10/2008)
You act like you're the first person to say that...
biaachmonkie 6:07PM (9/10/2008)
@Artie Lange
The silence can be fun as well, no need to add pointless noise to fast silent car to suit nostalgia alone. A few decades from now most people will probably be complaining about the noise from the few antique internal combustion powered cars remaining, they'll be banned from neighborhoods for noise pollution, etc.
The future is silent, get used to the idea of it.
Artie Lange 6:15PM (9/10/2008)
Biaach, please turn in your gearhead membership card. Do you know what a Weber carburetor sounds like? Ever heard a Ducati at high revs? Spare me the "you're old, get use to it"; I'm 23, and I have a CD full of nothing but vintage Le Mans racers WFO.
biaachmonkie 6:44PM (9/10/2008)
@Artie Lange
No I don't have a fetish for the internal combustion engine.
While the sound a big powerful engine or a high revving F1 engine is cool, so too is the silence from a electric motor with the same power, better torque, no oil to change, no filters to replace, no belts to break.
There are some people that love steam engines, and in the future you'll be part of the small and every shrinking group that loves internal combustion engines, but the world will move on. Progress man, deal with it.
PJ 7:11PM (9/10/2008)
Traveling in something that rolls on asphalt-bound wheels, and that exposes you to the elements, is never going to be "silent." Even if the electric-motor whine isn't all that noisy.
I'm okay with the futuristic soundtrack, but the Tesla *needs* a third pedal and shifter before I'll get on board. Arcane, maybe, but the art of manual shifting--as part of the enthusiast experience--will only become more and more relevant as surveillance tightens and roads crowd. In a decade or two, simply flooring it to extra-legal speeds to get your jollies isn't going to be a sustainable hobby anymore.
Artie Lange 8:09PM (9/10/2008)
"While the sound a big powerful engine or a high revving F1 engine is cool, so too is the silence from a electric motor..."
Perhaps, if you lack testicles.
Also, "silence" doesn't sound.
why not the LS2LS7? 8:44PM (9/10/2008)
http://www.autobloggreen.com/2007/12/29/would-the-tesla-roadster-be-a-suitable-track-car/
In the following, the importance is how the car backed itself off automatically, not the report of smoke that seems to be erroneous.
http://www.autobloggreen.com/2008/08/26/tesla-roadsters-reportedly-experience-glitches-during-euro-test/
Despite being the most performance-bred electric car so far, the Tesla can only go a few minutes at the track before it kills your joy automatically.
McLovin 10:28PM (9/10/2008)
Fartie Lange wrote:
"It may be the car of the future, but I hope its not the future of speed. A future of speed without the sound of internal combustion would be a very boring one."
Hope against hope I think. Decibels don't get you a zero to 60 time. The fact that the Tesla produces pretty much peak torque off the starting line is going to silense (pun intended) a lot of critics. I don't call a 0-60 in under 5 seconds boring at all.
@Corey,
You act like a little biaaaaachhh and I probably am not the first to say that.
McLovin
Gerald 11:37PM (9/10/2008)
If this is the future of spead, I don't look forward to this future. It seems incredibly boring.
JZeke 10:22AM (9/11/2008)
Actually, anyone ever hear a really powerful electric motor (with brushes) spin up?
While the first few electric sports cars are going to be quiet, theres a good chance the Bugatti EV of the far future is going to sound like a thunderbolt as massive arcs of excess charge spark off the brushes in the motors. Better yet, prepare to have ozone replace the trad smell of hydrocarbons as these electric powerhouses rip through the air.
Andrew 5:59PM (9/10/2008)
In space, no one can hear you speed
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DKB_SATX 5:53PM (9/10/2008)
"shockingly impressive"? Bad pun.
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Mark 6:15PM (9/10/2008)
funny thing is, nobody would have excepted this level of crap from a large company. I just hope the warranty is all inclusive.
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montoym 11:26PM (9/10/2008)
Quote from OppositeLock: -
"I think you're misunderstanding what's happening above 9000 RPM in the electric motor" -
Not according to even the Tesla website.
http://www.teslamotors.com/performance/acceleration_and_torque.php
That power curve doesn't speak well of high RPM performance. After 8K RPM, both HP and Torque drop off all the way to the 14K RPM redline.
Based on that dyno curve, I'd expect the Tesla to be closer to pulling off a sub 5sec 0-60 time than a 130mph top speed.
At the 14K RPM redline, the Tesla's motor is making around 100HP and about 50ft-lbs of torque. Those figures do appear to be at the wheels, but those are still fairly low figures for a "performance machine".
With a single speed gearbox, they'd have to use every bit of it that they can and it will be geared long in order to satisfy the high top speed. Long gearing and not a lot of power at high RPM's don't equal high speeds or scintalating performance at those high speeds and RPM's. There's no downshifting to get more performance at higher speeds either, you get what you get.
Looking over the other specs and using some online calculators, it appears that the Tesla is geared to hit almost exactly 120mph at 14K RPM. The overall final drive ratio is 8.28:1 and the rear tires are 225/45R17's. But, with the power dropping off at those higher speeds, I don't expect the ride from about 70mph(8K RPM, about where the power peaks) to 120mph to be incredibly quick or exciting.
So, it may be possible for for the Tesla to hit 120mph, but I think it's there more as just a theoretical limit(especially once wind resistance and drag are factored in) as opposed to one that most drivers are going to want to test out too often.
I still want to see some actual, instrumented road tests with the final 1.5 drivetrain and the higher-powered motor to see how it actually runs.
I still think the Tesla is a great technological wonder, bit I just think they should have worked towards actually giving the car the two-speed gearbox it deserves.
montoym 7:33PM (9/10/2008)
So, I'm wondering which of the design specs they are skimping on with the new 1-speed tranny?
I've noticed that since they mentioned the single-speed unit, not much has been said of the 4s 0-60 time or the 125mph top speed. I think they would be able to go with one or the other, but not both without a two-speed unit. Plus, a 69ft-lb increase in torque isn't going to be enough to satisfy both as others seemed to mention previously.
It is true that since it's an electric motor with a much higher redline than an IC car, that they can get away with fewer gears. But, having looked at the dyno sheet for the electric motor(granted it was the lower-powered unit), the power drops off dramatically after 9K RPM. So, in that case, it's really not too much different than an IC engine.
It's surely not going to be able to reach a high speed if they aim for the 4sec 0-60 time and if they focus on the 125mph top speed, the acceleration will suffer. Such is the of compromise with a single-speed gearbox.
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jake 8:47PM (9/10/2008)
They simply just changed the gearing so it is somewhere between the original 2 so that it can satisfy both the acceleration and the top speed. I believe with the 2 speed, the top speed was 130mph, which they subsequently electronically lowered to 125mph for safety. I believe they also raised the redline a little too in the drivetrain 1.5 from 13krpm to 14krpm so it can have the 125mph top speed.
The difference between an electric motor and an ICE is not the top end but the bottom end, with 100% torque @ 0rpm, dropping off at ~6-7krpm. That 100% torque @ 0rpm allows it to drive with just 1 speed. The 69lb-ft extra is able to satisfy the 0-60 in under 4 seconds because it is avaliable right at 0rpm, unlike in an ICE where it has to get up to the peak.
OppositeLock 9:09PM (9/10/2008)
I think you're misunderstanding what's happening above 9000 RPM in the electric motor. Power actually remains fairly constant, since power is RPM * torque. The motor has reached its peak rating, so as speed increases, torque decreases. In the Tesla's engine, the torque remains constant until the engine reaches its HP peak, then the HP remains constant for the rest of the time. It's as if you had a perfect CVT attached to a gas engine which was running at its HP peak.