LuckyLuke
Model S P90DL
I assume most sound we hear in the video comes from the dyno rollers and not from the car itself, right?
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First Dyno Video
- Thread starter lolachampcar
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FalconNinetyD
Active Member
Jalopnik has picked up the story...
http://jalopnik.com/5976242/watch-a-screaming-electric-tesla-model-s-dyno-run
http://jalopnik.com/5976242/watch-a-screaming-electric-tesla-model-s-dyno-run
wierd to see that kind of power curve.... I guess torque falls off with RPM on this motor. No wonder the car is such a hoot to drive on a daily basis.
Also note the brake light behavior. You see them flash 3x then go off, all the while the car is slowing down. Shouldn't regen be causing the brake lights to remain on as the car is slowing down, or am I mistaken that the brake light behavior is not based on rate of deceleration but rather something else? Or is that one of the "crazy errors" that was appearing?
When my car was delivered there was a huge energy spike at the very beginning of the graph--over 1000 if I remember correctly. Never have seen a peak that large since...maybe I need to put those 21 inchers back on and find some warm pavement!
Nickjhowe
Member
If that's on the Wh/mile graph, the way to get that is stop/start driving. Nudging along in nose-to-tail traffic on Atlantic Blvd in Delray Beach, FL I was up over 900 on a 1/2 stretch that was slower than walking pace.
Johan
Ex got M3 in the divorce, waiting for EU Model Y!
It's all physics/mechanics of the electric drivetrain. On a side note I've seen a lot of reviews where the write stuff like "the top speed is electronically limited at 130mph" or similar. Well, electronically no, electrically yes maybe as in "that's where the electricdrivetrain (with it's current gearing) maxes out".
Official graph from Tesla:
strider
Active Member
Physics. The energy required to spin the motor increases exponentially as the rpm increases so "power to the ground" drops off as rpms rise - the opposite of an ICE. That's why EVs are so fun - you don't have to wind them up to get full power.
EarlyAdopter
Active Member
Could be the result of back EMF as described by Lenz's law - as a motor's speed increases its electrical resistance also increases, reducing the amount of current that can flow into the motor.
In other words, the faster you go the more your motor wants to act like a generator, pushing current back to the battery rather than taking more current in.
Also, at those speeds friction losses and rotational air resistance losses within the motor really start to add up.
In other words, the faster you go the more your motor wants to act like a generator, pushing current back to the battery rather than taking more current in.
Also, at those speeds friction losses and rotational air resistance losses within the motor really start to add up.
I was driving around today and I noticed that the energy output meter was exceeding 320kW by a noticeable amount at full acceleration. This correlated with my "seat-of-the-pants" dyno perception that the car seems to have power closer to 500hp than to 416hp. Because the energy output gauge is a log-scale, the actual electrical output might be closer to 350kW. Converting this direcly to hp yields 470 hp.
Sure enough, I found this thread showing 386 wheel hp, which, when the standard ICE correction factor of 18% mechanical loss is applied, comes to exactly 470 hp at the crank.
Thanks, Tesla, for the extra performance. No wonder that Porsche Turbo couldn't get ahead of me the other day!
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Liz G
P03056
A couple of weeks ago I had my Standard 85 dyno'd, thought I'd post the numbers since I didn't see any previous standard 85 numbers posted.
Have to say it was a bit scary flooring my car at a brick wall, trusting only the safety straps they put on the car to keep it from crashing. I also had a heart stopping moment when all the errors started going off.
Scared the poor guy running the dyno too. He said "Floor it.".. I said "Floor it?"... He said "Yeah." So I did. Then he started screaming "Stop." I was getting so much torque at the wheels he was afraid I would break his dyno.
When it was all said and done these were the numbers we got, rolling on the pedal.
Have to say it was a bit scary flooring my car at a brick wall, trusting only the safety straps they put on the car to keep it from crashing. I also had a heart stopping moment when all the errors started going off.
Scared the poor guy running the dyno too. He said "Floor it.".. I said "Floor it?"... He said "Yeah." So I did. Then he started screaming "Stop." I was getting so much torque at the wheels he was afraid I would break his dyno.
When it was all said and done these were the numbers we got, rolling on the pedal.
865 torque. That is amazing!!
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Wouldn't the Tesla's mechanical loss be less than 18% being its drivetrain is much more efficient than an ICE?
Tommy
Member
Thanks for posting this, I always wondered what my 85 could turn. Being the curious type, I did some research on what the "WCF" stood for as both torque and HP were reduced. For those not in the know it stands for Weather Correction Factor. This factor, as the name implies, corrects for the differences in temperature, barometric pressure, etc taken at the time of the test so that the test results are repeatable. Here is a link that explains the WCF Performance Trends Blog Dyno Weather Correction Factors and a link that has a calculator to compute the WCF Dyno Correction Factor Calculator
My only question is: does this apply to an EV, as an EV at the very least shouldn't be affected by barometric pressure.
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