This is a large part of the difference between a P100D and a 100D, the P100D has larger motors / inverters and they discharge the battery at much higher C rates. So part of the additional margin is likely allocated towards higher warranty reserves.
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Petition Tesla to make the Model 3 Performance 0-60 <3s
- Thread starter Sutton 3P
- Start date
This is a large part of the difference between a P100D and a 100D, the P100D has larger motors / inverters and they discharge the battery at much higher C rates. So part of the additional margin is likely allocated towards higher warranty reserves.
AlanSubie4Life
Efficiency Obsessed Member
Is this true? In theory, with a different motor and/or programming, you could increase torque from the motor at low speeds, even if the ultimate HP limit (likely determined by the battery pack) was the same, and you could get a higher average power over the interval - of course you would hit that HP limit sooner (at a lower speed) since HP = Torque * RPM... So the 0-60 time should decrease if you had a motor & inverter combo that could deliver higher peak torque, without any battery pack changes.
I'm not aware that that peak torque would be limited by the pack - until you hit the HP limit.
However, perhaps there is some other limitation I am not aware of. There probably are tradeoffs to a fatter motor & inverter, of course.
I'm not familiar with these vehicles...but the faster acceleration off the line can't be limited by the pack, can it? Certainly it is discharging at a higher C for any given speed, since the acceleration is higher...but at 0mph it's close to a 0C discharge, since the required power is nearly zero, right?
These are really intended to be questions, not statements.
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Here's a Ludicrous Raven doing a Launch with the Stats page up on video. As you can see around 2:19 on the video, it hits peak battery power and becomes power limited around 40 mph or so.
Yes, a monster rear motor would allow a faster 0-30 time which would lead to a faster 0-60 time without battery changes for the P3D.
No, I don't think there's any chance Tesla could simply allow more power in the current motor to get you there safely. The Ravens use a much larger, much heavier rear motor to do it, which is capable of taking twice as much power.
So much misinformation on this thread. Why do people who don’t know what they’re talking about feel compelled to just make something up? Is this what the internet has done to us? 
AlanSubie4Life
Efficiency Obsessed Member
What, specifically? In terms of your fundamental question, what physically is limiting the low-speed torque on the P3D (before the HP limit is reached)?...I don't think anyone here knows the answer to that. Any answer would be speculation. It could exceed the capabilities of the inverter, it could exceed the capabilities of the motor windings, it could demagnetize the motor (I've heard that mentioned for very low speeds - and it is apparently true that very high magnetic fields from high peak currents in the windings would at some point risk de-magnetizing the permanent magnets...), it could overly stress mechanicals beyond their design rating, etc.
Lots of possibilities. All we can say we know for sure is that torque is currently constant from ~3mph to ~44mph (these are approximate numbers), and what limits that torque is anyone's guess out of the listed possibilities above, and additional unmentioned possibilities.
We also know that if torque is increased, it will start to drop off sooner than ~44mph due to the HP limit.
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This is asinine. What does a high end Porsche have to do with a Model 3? You bought what you bought. Don't expect more. Since when has a petition done anything?
Dan203
Active Member
The Model 3 performance can be had for a base price of $55,990. The base Taycan costs $150,900. These aren't even in the same league. I doubt Tesla will even give a second thought to the performance of the Model 3 because of this. I'm not even sure they'll care about the Model S compared to this, as they're very different cars with the only real similarity being they're expensive and electric. This "might" have some affect the design of the Roadster 2, or maybe even the price, but even that's kind of iffy.
My guess is they won't make the Model 3 any faster. The Roadster is coming out and is the flagship which is going to be 0-60 in high 1 second range, next in pecking order is Model 2 and X with Ludicrus mode which is in the 2.x range.
Would it be cool yes, do we need it to be that much quicker? What are the long term effects on the car?
Would it be cool yes, do we need it to be that much quicker? What are the long term effects on the car?
WilliamG
Hinge Fanatic
Not sure if that's necessarily completely true. Why not have a car that can shame another costing 3x as much in some metric? I think that's a huge seller for Tesla, especially among enthusiast. Seriously: Why not?
And clearly Elon does care, as he's already trolled Porsche once, and is now putting the Model S on the Nurburgring next week.
Dan203
Active Member
If this can truly be done with a simple software update and with no major effects on the longevity of the car, then I agree... why not. But if it's going to have some adverse effect on the car just for some d*ck measuring contest then it seems silly.
Yeah, exactly. I agree that it seems that so far no one who’s replied knows the answer and any answer so far is speculation. My issue is just annoyance that many people have offered speculation as an apparently informed opinion when much of it is clearly physically wrong.
I’m optimistic that someone will reply who has a good understanding of this subject. We’re on a major EV forum talking about the most hyped EV and why Tesla can’t drive more power through the motor at low rpm to push the performance tires near their limit? I think the guy talking about a fundamental current limit at any voltage may be on to something but the explanation is so far not there and inverter datasheets I’ve looked at suggest power dissipation in the inverter is largely proportional to V^2.
Any help from someone who (actually) knows about EV inverter design?
Since you are sure the others are wrong, maybe you could explain it for us?
See, the thing is you're essentially telling us that it's possible and there is additional margin for more power (without math) - but you seem to disagree when people state the opposite with equivalent technical reasoning to your initial hypothesis?
It's essentially a typed version of the guy sitting at the table drinking coffee meme saying "change my mind"
Physics aside, there is ZERO chance or need for a sub $75K car to break the 3 second mark. Sure that would be awesome, but the elasticity and sales that would be generated from that marginal improvement wouldn't be much. Model 3 already destroys everything in it's class so many people who want a fast car would already buy it since nothing else is even close (again in it's price range, because that certainly matters regardless of whether you explicitly asked about it). And the performance upgrade certainly wouldn't be "free" in terms of either new hardware, accelerated wear and degradation on components and/or Tesla's engineering time which is a very finite resource.
So no, i wouldn't sign a petition because it really doesn't make sense for Tesla as a business, even though personally i'd love to have the extra performance.
A VFD datasheet is quite unlikely to mention intrinsic limitations, since they’re entirely irrelevant to the end user. The heat dissipated in the drive is not the inherent limitation the vast majority of the time. If it was, a larger heat sink or fan will be all it takes to solve that. An LED can be driven well within its average power rating, and fail almost immediately if exposed to peak currents vastly exceeding its design. The bond wire junction on the die would most likely be the failure, but the average heat output would very easily be within spec. It’s not the apparent power dissipation that’s the limit in the majority of cases, it tends to be some much smaller effect often inside the package. A 5HP VFD can’t be made into a 10HP one with a larger fan. They have larger IGBT packages designed to pass more current. However, a 5HP motor can temporarily perform like a 10HP one, although you still need a 10HP drive to be able to output the extra power. You tend to get non linear scaling of output power with higher input power. So this is a real challenge, as the impact can very much be more significant than it initially appears. If a motor is 96% efficient at 100kW, but 94% efficient at 200kW, the heating is much more substantial than it may appear. That mythical motor would shed 4kW at the 100kW point, but 12kW at 200kW. Motors have intrinsic limitations. They may produce more power if you feed more in, but eventually there’s often a sharp knee in the curve and the efficiency starts to tank. Unless someone runs the Model 3 motors on a dyno with a custom controller, we won’t know what the response of it is. Typically one would design an inverter around the intrinsic limitations of the motor if performance is a factor. I understand this is speculation, but there’s no practical way to get the data, and it’s largely irrelevant anyways. The likelihood of significant overhead being built in is absurdly low. Inverters are very complex, and to the best of my knowledge the datasheet on the official packages Tesla is using is not available at this time. Even if it was, the math would involve considerable assumptions. There’s no way to know the actual current sharing Tesla is achieving in production. Without that info analysis isn’t really possible. I’ve been fiddling with inverters for about 15 years. I’ve blown many up trying to get more power out. You can’t just ask the silicon to do something it wasn’t designed for. More often than not, the devices are very well characterized and you can’t reliably go beyond the spec sheet. Driving a given motor at higher power requires more current. You have no control over the voltage. It would be illogical to design the inverter to handle current it will never see. And as current rises, so does electrical noise. The inverter would need to be able to snub the spikes otherwise the packages will pop even if the silicon can handle the current. Driving intrinsically inductive loads at high frequency causes voltage spikes on the switching events. As current rises, so does the energy in these spikes. This again is a gross oversimplification, and a huge number of other issues are at play. The rear drive unit likely has a fairly pronounced knee being a permanent magnet machine. A sensible engineer wouldn’t design the inverter bolted to it to be capable of driving it much past the knee.
The Taycan is 3x the price of a Model 3. Tesla could probably care less about whether the Taycan is faster or not. If the battery output was stronger they would definitely consider doing it to the S and make the upgrade coincide with the Taycan launch date to boost S sales and to troll Porsche.
Garlan Garner
Banned
When will it happen? NOW.....
I just officially had my P3D clocked at 2.7 twice in a row at a track in Joliet Il.
Knightshade
Well-Known Member
And you've had it pointed out, repeatedly, this is much faster than any other model 3 on earth has ever clocked and there's almost certainly something wrong with the equipment there.
Get yourself your own calibrated measuring device (draggy or vbox) and test... guaranteed it'll be no better than roughly 3.0 seconds give or take a few hundredths of a second.
Garlan Garner
Banned
@Knightshade
Come to the track with me. Its the autobahn in Joliet Il.
I'll get you in for free if you want to see it for yourself.
Come to the track with me. Its the autobahn in Joliet Il.
I'll get you in for free if you want to see it for yourself.
AlanSubie4Life
Efficiency Obsessed Member
High frame rate video with speedometer visible, or it did not happen.
Unless you dropped 600 pounds from your car, this did not happen.
