Racer.com: Charged Up

[TEG]

Tesla Roadster Sport: Charged up - Racer.com

 

[Tim]

I like these type of reviews. While certainly not unvarnished praise, it compares the roadster to other supercars in a no compromise sort of way. This is the next step for EV adoption where they can be compared to ICE cars directly without apologizing for the short-comings of BEVs. Similarly to what hybrids have had to go through. I imagine that in less than 10 years ICE supercars will not be able to compete with EVs performance or cost wise.

 

[doug]

From the article:

The Roadster Sport's AC induction motor is hand-woven with more copper than the standard car's powerplant, and it produces 40hp more and an extra 19lbft of torque as a result. If you prefer to measure such things in sheer current, the regular motor can draw 800 amps from the car's lithium ion battery at any one time; the Roadster Sport peaks at 1000 amps.

I wonder how accurate those current numbers are and where the author got them.

Tesla Motors - performance specs

Base: Output 248 peak horsepower (185kW) and 276 lb-ft (375 Nm) of torque. Redline at 14,000 rpm.
Sport: Output 288 peak horsepower (215kW) and 295 lb-ft (400 Nm) of torque. Redline at 14,000 rpm.

16% higher peak power, 7% more torque, but with 25% higher peak current. Lends further credence to this: Sport vs. Non-Sport the same motor?

 

[rolosrevenge]

16% higher peak power, 7% more torque, but with 25% higher peak current. Leads further credence to this: http://www.teslamotorsclub.com/tesla-roadster/3222-sport-vs-non-sport-same-motor.html

I asked the sales rep about this at the Seattle store and he assured me that the motor was hand wound with additional coils.

 

[malcolm]

Is this the first time we've had confirmation of panasonic (a.k.a. matsushita) batteries?

http://www.teslamotorsclub.com/batt...sushita-ramping-up-li-ion-production-evs.html

 

[dpeilow]

They've been mentioned in other stories recently.

 

[doug]

I asked the sales rep about this at the Seattle store and he assured me that the motor was hand wound with additional coils.

Additional coils compared to what, though. Compared to the base 2010MY Roadster motor or to the 2008MY motor. I'm pretty sure the latter is true, just not so sure about the former. I'm not particularly concerned either way. Just my physics intuition says the increased Sport performance could be from the increased current alone. Then again the author's information might be incorrect.

 

[Tim]

16% higher peak power, 7% more torque, but with 25% higher peak current. Leads further credence to this: http://www.teslamotorsclub.com/tesla-roadster/3222-sport-vs-non-sport-same-motor.html

I don't think having a hand wound motor would increase the current rating like the article mentioned. More turns means more flux for the same amount of current and higher power for a given voltage and speed, but the current limit is more a function of the PEMs IGBTs and heat dissipation of the motor. I'd like to see some confirmation of the 25% peak current increase from someone at Tesla before I believed it. I remember reading from someone at Tesla that the 2010 motor is constructed somewhat differently(and more efficiently) than the 2008, but I haven't ever heard of a PEM upgrade for the sport.

That being said, I agree with Doug that the numbers as given by the article don't make sense.

 

[rsquared99]

When I had an overheat problem this summer, the service department swapped the PEM here at my home in Arizona. The PEM that was FedEx'd to my home was labeled a sport PEM. Neither the tech or I noticed that until he had done the swap and discovered the difference in testing. So, he remained in town overnight while they sent him the proper cabling so he could reconfigure the sport PEM to a non-sport PEM. So, there is a difference in the software, not necessarily physically. In the end, it all made no difference in that the engineers determined my original PEM was fine and had done what it was designed to do. They reinstalled the original PEM and decided to make a software adjustment to the heat limit the PEM was supposed to allow.