New Launch Mode - firmware 2.9.40

[Andyw2100]

In the car industry it seems like there is no expectation that the press car you get is necessarily the same as a customer car. A lot of times you might get a pre-production unit where a lot of things can change.

Ferrari is the most known for rigging their press cars, but we only know that because some journalists chose to expose that, although most keep quiet because they want continued access to press cars.

Fair enough. But I'm still left wondering about the description of the launch control as the "new launch control feature." Either the writer had to know it was new because he had something else to compare it to, or Tesla identified it as new. And if it was the former, wouldn't that be an odd thing for a writer to do if it's understood the car he or she is testing may be different from customer cars? I guess one reasonable possibility is that Tesla identified it as new for the writer, expecting the feature to be in wide release by the time the article was published, and just didn't meet that schedule.

 

[stopcrazypp]

Fair enough. But I'm still left wondering about the description of the launch control as the "new launch control feature." Either the writer had to know it was new because he had something else to compare it to, or Tesla identified it as new. And if it was the former, wouldn't that be an odd thing for a writer to do if it's understood the car he or she is testing may be different from customer cars? I guess one reasonable possibility is that Tesla identified it as new for the writer, expecting the feature to be in wide release by the time the article was published, and just didn't meet that schedule.

This situation might be weird in any other car, but given there is probably no auto journalist out there that doesn't know that the Model S is updated OTA, they probably assumed even if it wasn't present yet that it'll be uploaded to cars very soon.

 

[lolachampcar]

No it's not. Close sometimes, but batteries are not ideal voltage sources.

OK
Lucy, you got some splaining to do.....

At any instant, power delivered is instantaneous voltage times instantaneous current. These observations occur down stream of the battery and can be made without knowledge of the current source or its associated source impedance. Now if you want to say ongoing delivery is a function of the current source, that is a different matter but I believe P=IV is still valid (and the universe is still expanding ).

 

[sillydriver]

So...here's a question for those of you with more experience with this.

When the "Motor Trend" article first came out, most of us thought the author just confused "Launch Mode" with "Max Battery Power." It's now pretty clear, though, that wasn't the case, and the car supplied to "Motor Trend" really did have the Launch Mode recently released in some firmware versions. My question is if Tesla was providing a car that was running firmware that was not yet available to the public, did they have an obligation to tell the writer from "Motor Trend" that? And if Tesla did disclose the information (we have no reason to believe they did not) did the writer have an obligation to explain in his article that he was testing a car with software that was not yet publicly available?

This is the relevant excerpt from the article:

"With Ludicrous mode engaged and using the new launch control feature, 60 mph in the Tesla comes in a staggeringly quick 2.6 seconds with the driver experiencing a peak of 1.1 g up through 14 mph."

Obviously I don't have 'more experience with this', but I expect they told MT '... and it has our new launch control feature for 2016' not reminding MT that for Tesla, 2016 really means 2016, rather than 'next week' which is about when the 2016 models would have shipped for all the other auto makers.:smile:

- - - Updated - - -

OK
Lucy, you got some splaining to do.....

At any instant, power delivered is instantaneous voltage times instantaneous current. These observations occur down stream of the battery and can be made without knowledge of the current source or its associated source impedance. Now if you want to say ongoing delivery is a function of the current source, that is a different matter but I believe P=IV is still valid (and the universe is still expanding ).

I'm probably missing something because I'm not an EE, but wouldn't a real battery be an ideal voltage source in series with a resistor that represents all the sources of internal pack resistance? Then voltage might be 403.2 at 100% so and no current as in wk's chart, but at high current it's v0 - I * R-internal. And the power is v0 * I - I^2 * R-internal, which would be a downward-bending curve with current, just like wk's chart?

 

[lolachampcar]

As Stop pointed out, battery internal resistance and P=IV are two completely separate concepts.

 

[Johan]

so fiksegts... any results from your testing.

(It would of course be prudent to charge to 100%, do a few runs, let it cool and do it again at around 90% to see which claim is more correct: that 100% is quicker or that 90% SOC is quicker.)

 

[sillydriver]

As Stop pointed out, battery internal resistance and P=IV are two completely separate concepts.

That is of course literally correct, but I thought you two might have just been talking past each other in that as you point out, if I and V are both independent variables then P = IV always, but if you take the current I to be the sole independent variable (and the x axis of a chart) in a battery with internal resistance, then V and P are the expressions above and plotted on wk's chart. Both formulations are correct, but just saying different things.

 

[fiksegts]

I did that, car was a bit slower at 90%, but not by much....

P90D Ludicrous launch mode test

so fiksegts... any results from your testing.

(It would of course be prudent to charge to 100%, do a few runs, let it cool and do it again at around 90% to see which claim is more correct: that 100% is quicker or that 90% SOC is quicker.)

 

[Andyw2100]

I did that, car was a bit slower at 90%, but not by much....

Thanks for taking the time to make this video! As always, your efforts are appreciated!

I have a couple of observations and related questions about the video.

It looks as if when you were driving around, just before the launches, you had a regen limit, indicating the battery pack was fairly cold. It was gone by the time you did the launch on the video. Looking at your power meter, it looks as if you probably did one launch between driving around and the launch on the video, but not a heck of a lot of other driving. So my question is, could the fact that the battery may still have been on the coolish side have negatively impacted all the car was capable of?

Also the yellow exclamation point error symbol appears in the power meter right at the end of your launch. What did that indicate?

 

[Bulletproof]

Here's a another clip of the launch mode. A lot of talking. Actual test starts at 3:02 and its very brief then pauses so you can read the numbers. You still get a sense of how insanely fast it is though

 

[fiksegts]

car was charged fully and max power was enabled and "ready" while still connected to the HPWC..... seeing that it said 'ready' the car battery was warm, I'm not sure what the yellow triangle was, I saw it as well... no other message with it...

I did quite a few runs, when the car got hotter it slowed down a little, I also got the "cooling" message instead of "ready" in the max battery power dialog area after two runs....

Thanks for taking the time to make this video! As always, your efforts are appreciated!

I have a couple of observations and related questions about the video.

It looks as if when you were driving around, just before the launches, you had a regen limit, indicating the battery pack was fairly cold. It was gone by the time you did the launch on the video. Looking at your power meter, it looks as if you probably did one launch between driving around and the launch on the video, but not a heck of a lot of other driving. So my question is, could the fact that the battery may still have been on the coolish side have negatively impacted all the car was capable of?

Also the yellow exclamation point error symbol appears in the power meter right at the end of your launch. What did that indicate?

 

[Andyw2100]

car was charged fully and max power was enabled and "ready" while still connected to the HPWC..... seeing that it said 'ready' the car battery was warm, I'm not sure what the yellow triangle was, I saw it as well... no other message with it...

I did quite a few runs, when the car got hotter it slowed down a little, I also got the "cooling" message instead of "ready" in the max battery power dialog area after two runs....

That's interesting.

Perhaps the regen braking limit was due to the pack being fully charged, then, and not due to the pack being cold. I should have thought of that, but considering I am always driving in the cold, and never driving with a 100% charged pack, I didn't. Apologies.

 

[3mp_kwh]

I wonder if MT got version 2.9."39"? If the battery shows "cooling" status, it sounds like that system shares battery capacity.

It looks as if when you were driving around, just before the launches, you had a regen limit, indicating the battery pack was fairly cold.

Regen hashmarks also come at full 100%, range-charge.

 

[Andyw2100]

Regen hashmarks also come at full 100%, range-charge.

Yup. Figured out that that was almost certainly what it was and posted shortly before you posted.

 

[NSX1992]

I did my second test this morning after 90% charge but I had to wait as it needed 30 minutes of heating. So I was down to 85% when I floored it. I could not tell any difference from last nights 60% charge. So have to wait till I go to the dragstrip.

 

[benjiejr]

I'd love to see a video from the outside of the car of the rear end squatting when enabling launch mode!

 

[etm33]

I'd love to see a video from the outside of the car of the rear end squatting when enabling launch mode!

Everyone's a cinematographer

But that actually would be cool to see.

 

[AWDtsla]

Everyone's a cinematographer

But that actually would be cool to see.

While we're directing: Leave the camera near the ground behind one of the rear wheels so you can see the side of the car as it launches.

 

[wk057]

OK
Lucy, you got some splaining to do.....

At any instant, power delivered is instantaneous voltage times instantaneous current. These observations occur down stream of the battery and can be made without knowledge of the current source or its associated source impedance. Now if you want to say ongoing delivery is a function of the current source, that is a different matter but I believe P=IV is still valid (and the universe is still expanding ).

Guess I've just been getting annoyed with people misunderstanding how the battery works. You said power from the battery is P=IV, but it's just not that simple in the real world. Sure, measured downstream somewhere at an instantaneous point this is correct. But you can't use voltage measurements of the pack while not under load to determine power at a given amperage, which everyone seems to want to do with EVs to be able to say they can put out way more power than they're actually capable of, like when people quoted Elon Musk's 1500A number people jumped around saying the car could put out 600kW... which looks a lot like the math in a recent post on this very thread...

So sure, if you measure V and I while drawing some amount of P from the battery, then this is valid. But, for example, if I have a battery that reads 400V, and I want 400kW from it, you can't just plug in the numbers and say, poof 1000A are needed, or if I draw 1000A I'll get 400kW... since a battery is not an ideal voltage source. That's what I was getting at.

 

[Auzie]

I'd love to see a video from the outside of the car of the rear end squatting when enabling launch mode!

Everyone's a cinematographer

But that actually would be cool to see.

Enjoy the Froggo squat and launch, until we get Tesla squat and launch

I wonder what times did Froggo make, is the leap better with or without bugs inside?