"Secret Sauce" power upgrade coming - beyond Ludicrous

[tom66]

I watched the video before it was taken down. I stumbled upon this article that came out a while ago. You'll notice that it uses the same secret sauce phrase. Perhaps the upgrade he was testing out was tuned for performance rather than an increase in range.

Temporarily increased inverter efficiency could mean more power from the batteries reaching the motors, subsequently resulting in a performance increase? I don't know I'm grasping at shadows.

Barnacules on Twitter

Trip Chowdry needs to do some more research. Tesla's AC induction inverters already vary the frequency on the output. Since the AC induction motor is synchronous the output frequency of the inverter is related to the speed of the motor.

The inverter is already very efficient, around 90%. Getting higher than that with just software will be difficult. It might be possible, Tesla do tweak motor firmware almost weekly with software updates, but I'd be surprised if they could squeeze more than 1-2% more out of the current hardware. IOW, if there is a secret sauce upgrade it's either going to need better hardware or it's going to risk early hardware failure. Perhaps they could allow it only once every hour for 5 minutes or something, but I doubt you'll be using it all the time.

 

[FlasherZ]

I watched the video before it was taken down. I stumbled upon this article that came out a while ago. You'll notice that it uses the same secret sauce phrase. Perhaps the upgrade he was testing out was tuned for performance rather than an increase in range.

Temporarily increased inverter efficiency could mean more power from the batteries reaching the motors, subsequently resulting in a performance increase? I don't know I'm grasping at shadows.

Barnacules on Twitter

That article was written amidst a flurry of conversation on forums as well. The conclusion was that they could tweak the algorithms to get a little bit more out of it, but anyone expecting a near-step-change difference was going to be disappointing. Physics is still physics.

"Secret sauce" is used in the business world far too much, I'm afraid, to link these two.

 

[R.S]

Trip Chowdry needs to do some more research. Tesla's AC induction inverters already vary the frequency on the output. Since the AC induction motor is synchronous the output frequency of the inverter is related to the speed of the motor.

The inverter is already very efficient, around 90%. Getting higher than that with just software will be difficult. It might be possible, Tesla do tweak motor firmware almost weekly with software updates, but I'd be surprised if they could squeeze more than 1-2% more out of the current hardware. IOW, if there is a secret sauce upgrade it's either going to need better hardware or it's going to risk early hardware failure. Perhaps they could allow it only once every hour for 5 minutes or something, but I doubt you'll be using it all the time.

While you are right, that inverters already switch output frequencies, you are not right.

An IGBT has a fixed switching frequency and with that frequency it modulates lower frequencies. To give you an example, imagine one "I" would be a 10ms voltage peak of 100% and "." would be a 10ms voltage of 0%. Now you can go "I.I.I.I.I." which has the frequency of 100Hz, but you can also go "I..II.III.II.I.." which would be 6.25Hz. Both modulate sine signals, but also have other frequencies in them (think Fourier series), which actually reduces motor efficiency. If you switch faster, the inverter losses increase, but the motor losses decrease, if you switch not so fast the inverter losses decrease and the motor losses increase.

And another thing, an induction motor runs asynchronous to the inverter frequency. It only runs in sync, if it produces no torque. Induction can only happen if the magnetic field of the stator moves faster than the rotor. Because -B d/dt = rot E

 

[tom66]

I am reasonably certain Tesla use variable switching frequency, as well as inverter frequency. The inverter harmonics seem to change, indicating this.

You are correct frequency is only proportional to speed when the motor is theoretically unloaded. Some slip is necessary to create torque.

 

[R.S]

I am reasonably certain Tesla use variable switching frequency, as well as inverter frequency. The inverter harmonics seem to change, indicating this.

You are correct frequency is only proportional to speed when the motor is theoretically unloaded. Some slip is necessary to create torque.

That could very well be, it would also make sense, although it would not be necessary. It is also more complicated, because you never want one bridge to short, which could happen more easily, if you change the switching frequencies dynamically, since the IGBT takes some time to shut off. Its a very complex topic, especially if you also want to reduce the voltage with the inverter. I always wondered if you could let a Buck-Boost converter do the voltage at the DC-part and use the inverter just for modulating the sine wave, but I guess that would be too expensive.

But how do you know the inverter harmonics change? Just out of interest.

 

[AZ Desert Driver]

So some of you guys prowl with Ludicrous enabled super cars. Part of me wants that throbbing power...but the sane(er) part of me says that such power is fleeting. That after a week or month of jackrabbit starts, one would "grow up" and begin driving in traffic like a good neighbor. One might tap intoLudicrous on fewer and fewer occasions.

Don't know if this "maturing" happens, but if it does, does that mean the Ludicrous mode is a fleeting purchase? Should I invest my nickles into other - more durable - options?

 

[Andyw2100]

So some of you guys prowl with Ludicrous enabled super cars. Part of me wants that throbbing power...but the sane(er) part of me says that such power is fleeting. That after a week or month of jackrabbit starts, one would "grow up" and begin driving in traffic like a good neighbor. One might tap intoLudicrous on fewer and fewer occasions.

Don't know if this "maturing" happens, but if it does, does that mean the Ludicrous mode is a fleeting purchase? Should I invest my nickles into other - more durable - options?

I drove with "Insane" mode enabled all the time, and now drive with "Ludicrous" mode enabled all the time, as does my wife. I assure you she never comes close to making use of the power Ludicrous can provide, and I almost never do. (The exceptions for me would be if I'm showing the car off to someone, or trying to test something.) All that being said, it's nice to know the power is there if and when I want it.

 

[thnp]

Eearlier, when buying cars I've always used the argument: "it's nice to have that extra power at hand for passing other cars etc", and then bought a slightly larger engine than I actually required ... But with the Tesla... Even the base fulfills this requirement.... When I got my S85 and then my 70D I just couldn't get myself to even think about a P-version... The base models are just... Enough...

For me at least - but everyone is different!

 

[Jason S]

Sometimes the extra power is nice. You find yourself in the wrong lane, you didn't see the oncoming car when pulling out, etc. I would drive with the option always on if given the choice.
I wouldn't, however, use launch control on every chance. That's just looking for trouble.

 

[anxman]

So some of you guys prowl with Ludicrous enabled super cars. Part of me wants that throbbing power...but the sane(er) part of me says that such power is fleeting. That after a week or month of jackrabbit starts, one would "grow up" and begin driving in traffic like a good neighbor. One might tap intoLudicrous on fewer and fewer occasions.

Don't know if this "maturing" happens, but if it does, does that mean the Ludicrous mode is a fleeting purchase? Should I invest my nickles into other - more durable - options?

This is accurate. Eventually the novelty wears off and you use it less and less. It's just fun and nice to use it when I'm in the mood but really serves no practical purpose.

Now that the 90D is so beefy, I don't see any reason to spring for the P.

 

[AZ Desert Driver]

I'm trying to configure my Model 3....I am thinking Dual motor, 70 kw battery( I want max range, even if primary trip is local, want option of range up to 250 miles...same as gas tank)
No air suspension, no P or L.
I think you just convinced me on P and L. ( base level will still be awesome)
Still soft on Air. Heard there are lots of problems that make this small feature too expensive. True?

 

[AZ Desert Driver]

Dummy question - I don't know what the difference is between: Insane, Ludicrous and Launch - they seem to be the same, just rotating names. True?

 

[thimel]

Dummy question - I don't know what the difference is between: Insane, Ludicrous and Launch - they seem to be the same, just rotating names. True?

They are different. Insane mode comes with the dual motor cars that have the model number starting with P. They have a bigger rear motor than the non-P cars. Ludicrous is a $10,000 upgrade to those cars that provides improved fuse, contractors and software so about ten percent more power is available. This reduces 0-60 times by about 0.2 seconds.
Launch is used informally to mean flooring it from a stop. "Launch control" is a special series of accelerator and brake pedal presses that one can use to get a good launch. Most find that just mashing the pedal works fine.
Hope this helps.

 

[cheshire cat]

would like to see more on "air" too

 

[sorka]

Dummy question - I don't know what the difference is between: Insane, Ludicrous and Launch - they seem to be the same, just rotating names. True?

Same up to 45 MPH and then 10% more power from 45+ and up.

 

[AZ Desert Driver]

They are different. Insane mode comes with the dual motor cars that have the model number starting with P. They have a bigger rear motor than the non-P cars. Ludicrous is a $10,000 upgrade to those cars that provides improved fuse, contractors and software so about ten percent more power is available. This reduces 0-60 times by about 0.2 seconds.
Launch is used informally to mean flooring it from a stop. "Launch control" is a special series of accelerator and brake pedal presses that one can use to get a good launch. Most find that just mashing the pedal works fine.
Hope this helps.

Very good answer. Thanks.
This clears up why "over the air upgrade" won't get Ludicrous mode running. The car has to be built with those fuses...which don't come over the air. You just saved me $10,000 (in parts) plus more $ in fines/crashes from reverting to my teenage impulses.

 

[P85DBeast]

Whats next? the P100D+ And i bet the 0-60 is going to be about 2.3 Seconds and after that an even faster car! with a 0-60 of about 1.0 Second is that when Tesla's gonna stop b/c the Lamborghini and Bugatti might get jealous..... but heck they probably are already jealous!!

 

[R.S]

Whats next? the P100D+ And i bet the 0-60 is going to be about 2.3 Seconds and after that an even faster car! with a 0-60 of about 1.0 Second is that when Tesla's gonna stop b/c the Lamborghini and Bugatti might get jealous..... but heck they probably are already jealous!!

Without changing the tires, or doing some aerodynamic miracles, the lateral acceleration seems to have its maximum at 1.1g, for the Model S. So the minimal time to get to 60 mph, would be 2.486 seconds. The power needed to do that must be higher than 637 kW (854hp), based on a 2.2 ton Model S. If you increase power even more, without changing the rest, you just get faster to speeds above 60mph, but the 0-60 time stays unchanged.

 

[AZ Desert Driver]

Without changing the tires, or doing some aerodynamic miracles, the lateral acceleration seems to have its maximum at 1.1g, for the Model S. So the minimal time to get to 60 mph, would be 2.486 seconds. The power needed to do that must be higher than 637 kW (854hp), based on a 2.2 ton Model S. If you increase power even more, without changing the rest, you just get faster to speeds above 60mph, but the 0-60 time stays unchanged.

I have spent my career as an engineer - specializing in material science. Many degrees, many hours in research labs. Your calculations SOUND fully reasonable. I've never been exposed to that flavor of physics. Can you illuminate how you got to these amazing figures? i.e. - how 1.1 g can be obtained - even with sticky tires. How 854 hp can't accelerate faster, just increase top speed. I am not doubting you. I've just never been exposed to these types of calculations.

 

[R.S]

I have spent my career as an engineer - specializing in material science. Many degrees, many hours in research labs. Your calculations SOUND fully reasonable. I've never been exposed to that flavor of physics. Can you illuminate how you got to these amazing figures? i.e. - how 1.1 g can be obtained - even with sticky tires. How 854 hp can't accelerate faster, just increase top speed. I am not doubting you. I've just never been exposed to these types of calculations.

For the 1.1g, thats something you might have to ask another material scientist, maybe even someone who deals with aerodynamics. If I'd had to guess its just the friction coefficient. But from acceleration data, we can see that its around 1.1g, it could be higher, but it sounds reasonable for a performance oriented car.

The power calculation, thats pretty easy. For that, we just need basic physics and my field of expertise, rotating electrical machines. As most know the typical electrical machine, has a flat torque curve from zero, but what many don't know is that at the point of maximum power, that changes and it becomes something like a flat power curve. So the torque curve goes down with the the increase of rotational speed/rpm. There is one point, where torque and power it at its maximum. If we would plot torque and power, over the rpm, its the point where at higher rpm the toque decreases, while at lower rpm the power decreases.

Maybe we need to clarify what torque exactly is. Torque is force times radiant and it can be geared up, or down. Thats one of the reasons why talking about motor toque in EVs is rather pointless. In the end the torque is transmitted to the road, as force. If the force is higher than the nominal force of the car, times the friction coefficient, the wheel slips.

So to get the fastest to 60mph, with a given friction coefficient, at minimal power. We just need to gear the car that way that we have the point of maximum power and toque at 60mph, because we have no multiple gear transmission, where we could switch the transmission ratio.

That way we have 1.1g of acceleration up until 60mph, which gives us the minimal time from 0-60, 2.486s. If we want to go lower, we need a higher friction coefficient.

Now we calculate the power. 1.1g times 2.2 tons, gives us the force needed, 23.74 kN. And since power is force times speed, we have 60mph*23.74kN, which is 637kW. Thats the minimal power needed. If we have more power, we could either leave the gearing the same, which would result in spinning wheels, but a higher acceleration at high speeds, or we gear up and set the point of maximum power at a higher rpm, which has basically the same effect. It would still accelerate slower than the lower geared car, but top speed would increase.