3.8Mw Electric hypercar

[kdog]

What do you think of this? Is this hyperBS or actually possible in a car.....3840kw?
Seems like fantasy but what can $2.4mill get you?
Even at 1000v that's 3840 amps, or 7.7kA at 500v
https://www.caradvice.com.au/892354/ali ... -hypercar/

[Balmorhea]

It sure smells like bullshit. Looks slightly uglier, though.

[kdog]

Quite the gamble if you drop the $$ on the pre-order. But unless you're into EVs how would you know?

[Upperfoot]

Well a dragster was being worked on with those specs (exc range) https://insideevs.com/news/408448/ev-dr ... australia/

[The Toecutter]

It's plausible.

The 5AH LoneStar cell can do 500A continuous with a weight of 0.13 kg, 3.7V nominal, 0.0008 Ohms resistance. A 3,840 kW capable pack would have a battery weight of 302 kg using these cells, not including BMS/cooling/housing/ect.

The motors and controllers are going to be some real monsters. A series DC system with six Netgain WarP 11" HV motors and 3 Soliton Shivas could come close to handling that sort of power for at least a few seconds at a time(5-10), and that's just at the hobbyist/amateur level. Even with OEM components rated for these specs, if they even exist, the "racing" version of this car is probably going to be a 4,000+ lb lardass.

The car rendering is ugly and looks like a ripoff of an ugly Lamborghini. Personally, I don't believe their claims.

[Hillhater]

Doesnt it use 24 motors ?.....6 on each wheel.
That would “only” need 160kW per motor!
And the 60kWh pack would “only” need to be 65C capable,....just for a minute or so !

[The Toecutter]

Doesnt it use 24 motors ?.....6 on each wheel.
That would “only” need 160kW per motor!
And the 60kWh pack would “only” need to be 65C capable,....just for a minute or so !

24 motors would be a strange design. I'd like to see the specs of them, assuming they even exist. I don't think they'd power the wheels directly, but through some kind of gear ratio.

5 kW peak power per 1 lb of synchronous reluctance or synchronous reactance motor is not out of the realm of feasibility as efficiencies approach 98%. You'd need a bit over 700 lbs of motor to handle this 3,680 kW, in the best of circumstances. Not impossible, but it would require quite a unique vehicle design to fit this drive system into the vehicle. Using 24 motors would seem a bit Rube Goldberg to me, necessitating a complicated means of adding the power output of the motors together to the drive wheels, but it is again, not impossible.

Reliable and long-lasting batteries capable of 100C continuous are out there, off the shelf, available to purchase by hobbyists.

https://lonestarevperformance.com/sleeper-cells.html

This amount of power would be so ridiculous that the car would be at its claimed 300 mph top speed from a stop in less than 8 seconds assuming it weighed around 4,000 lbs. I don't see that happening on standard street tires, but there are racing tires that theoretically would allow this on a sticky enough track.

[Hillhater]

Sure, some individual components are realistic, ..
160 kw motors are available, but how much does 6 of them weigh, and how does that work on each wheel ?
Powerful cells are not a problem, but what use is 60kWh when you have 3800 kW to play with ?
Anything is possible, but this,, like much of the “ideas” on the net, is just click bait crap !
Its the modern equivalent to what used to be schoolboy doodles in a scrap book.

[The Toecutter]

Sure, some individual components are realistic, ..
160 kw motors are available, but how much does 6 of them weigh, and how does that work on each wheel ?

Would be interesting if they showed us some specs. It would generally be more space/weight efficient to use one or two large motors instead of 24 of them.

Powerful cells are not a problem, but what use is 60kWh when you have 3800 kW to play with ?

60 kWh would be enough capacity to get it around the Nurburgring at full throttle(when it's not braking or cornering), possibly in record time.

Anything is possible, but this,, like much of the “ideas” on the net, is just click bait crap !
Its the modern equivalent to what used to be schoolboy doodles in a scrap book.

I agree. However, there is a possibility my assessment that it is click bait/scam could end up proven incorrect. The technology to build a car of this sort is definitely here, and has been for at least a few years.

[Hillhater]

60 kWh would be enough capacity to get it around the Nurburgring at full throttle(when it's not braking or cornering), possibly in record time.....

Err no ?
Even at its constant 488km/hr it would take 2.6 mins to run 20.8 km of Nurburgring equivalent straight road..
BUT at 3800kW, .. that 60 kWh pack only lasts < 1 minute !!
I assume they have a bigger pack for their claimed 1000+ km range. !...( or maybe a tow truck & trailer )

[The Toecutter]

Err no ?
Even at its constant 488km/hr it would take 2.6 mins to run 20.8 km of Nurburgring equivalent straight road..
BUT at 3800kW, .. that 60 kWh pack only lasts < 1 minute !!
I assume they have a bigger pack for their claimed 1000+ km range. !...( or maybe a tow truck & trailer )

Even at full acceleration, it will very likely not be drawing the full 3,800 kW, as that operating point is going to be a narrow range of the vehicle's performance curve. The RPM has to rise to allow the power draw to increase for a given amount of torque output.

Even at top speed, it's probably going to consume closer to 1,800 kW than the full 3,800 kW. The 3,800 kW draw would only manifest during hard accelerations when the motor/controller is at the peak power section of its operating curve, likely when the car is already at 200+ mph, and there won't be many sections of the track where this operating point can be used.

Given the performance of existing electric cars that have set records on that track, 60 kWh is probably enough for at least one lap around the Nurburgring, considering the accelerator is going to be treated like an on/off switch, and given that its hypothetical performance curve would be so monstrous that the car's accelerator would only be engaged for about 1/4 of the lap, with the rest of the duration spent braking and cornering, otherwise the driver will crash entering a turn too fast. Then there's the 5-10% or so that will be recovered through regen.

If such a car were ever to become a reality, driving it around a curvy track would require the utmost discipline. 1/10th of a second too late braking would mean the difference between going through the apex of a corner at the optimum speed and crashing. Driving such a thing at 10/10ths would be highly stressful, IMO.

[Hillhater]

It could likely do several laps if they didnt use the full performance,...
..but that is not what you suggested previously.

60 kWh would be enough capacity to get it around the Nurburgring at full throttle(when it's not braking or cornering), possibly in record time.

“Full Throttle” means max power ..continuous . And the ‘ring is 80+% full throttle for most cars
So less than a minute run time , and less than 10 km range !!
Yes, i know it is totally impractical, but so is the whole concept of this rediculous idea.

[The Toecutter]

Full throttle actually means max torque. If the accelerator is all the way to the floor and the car is at or near stall, it isn't even at 1% of peak power. The RPM has to rise for power demand to rise. Simple mathematics can demonstrate this. For most of the time the car is at full throttle, it will probably be using half or less of its peak power, if it is a single speed(a multi-speed transmission would negate this argument, but at that amount of power, a multi-speed transmission would be uselessly redundant given the limits of the tires).

Most(all) cars at the 'ring don't have 3,700 kW. A car with that amount of power will be able to accelerate much faster than it will be able to decelerate with its brakes, even if it dragged a parachute behind it when it did brake(impractical for a circuit track, mind you). Even for the best drivers in the world, it would be impossible to drive to its full potential. You get onto a short 700 foot straight coming out of a turn at 85 mph, slam down the accelerator, and within 300 feet and about 2 seconds, you're at about 150 mph and have to brake to slow down for the next turn... if you brake 20 feet too late, you crash, which gives you a mere less than 1/10th of a second window to react between slowing down too soon to enter the turn at something close to the ideal speed, or slowing down too late and being destined to wreck, and you'll still be WELL away from the turn before you absolutely must slow down, making it that much more difficult to judge the distance.

Yeah, that is ridiculous. Utterly so. It would be harrowing as hell to drive all out.

...and such a ridiculous thing is possible to do with the technology that existed 5 years ago, let alone with what exists now.

But there comes a point to where the driver is physically incapable of ever making use of the car's true performance potential due to limits of human reaction time. One would really need autonomous technology by that point to set the best possible lap records, which would remove driver skill from the equation altogether.

[Dauntless]

24 motors would be a strange design. I'd like to see the specs of them, assuming they even exist. I don't think they'd power the wheels directly, but through some kind of gear ratio.

http://d2uwzav5gtex9t.cloudfront.net/ox ... g_cars.pdf

Remember Lord Drayson? (Or whatever.)

Stackable motors. https://www.yasa.com/yasa-p400/

[Hillhater]

Full throttle actually means max torque. If the accelerator is all the way to the floor and the car is at or near stall, it isn't even at 1% of peak power. The RPM has to rise for power demand to rise. Simple mathematics can demonstrate this. For most of the time the car is at full throttle, it will probably be using half or less of its peak power, ....

Just to continue the tech discussion rather than any hint at practicality..
“Maximum Torque” from a DC motor requires maximum current.
Maximum current implies maximum demand on the battery supply, IE max power draw “from the battery”.
Your proposition full throttle a low speed only representing 1% of peak power is only true for MOTOR OUTPUT power.
So anytime it is at “full throttle” it will be sucking maximum power from the pack.
Oh, and “Max torque” normally requires a LOT more current than max power !
.. ut that all depends on controller settings etc .

[The Toecutter]

http://d2uwzav5gtex9t.cloudfront.net/ox ... g_cars.pdf

Remember Lord Drayson? (Or whatever.)

Stackable motors. https://www.yasa.com/yasa-p400/

Interesting. I've not come across this specific motor before, but have read of similar motors. Metric Mind used to sell pancake stackable asynchronous 3-phase AC motors.

Given the unsprung weight necessitated by having 6 motors coupled to each wheel, the car's cornering capabilities would probably not be very agile...

Just to continue the tech discussion rather than any hint at practicality..
“Maximum Torque” from a DC motor requires maximum current.
Maximum current implies maximum demand on the battery supply, IE max power draw “from the battery”.
Your proposition full throttle a low speed only representing 1% of peak power is only true for MOTOR OUTPUT power.
So anytime it is at “full throttle” it will be sucking maximum power from the pack.
Oh, and “Max torque” normally requires a LOT more current than max power !
.. ut that all depends on controller settings etc .

I have a conversion of a Triumph GT6 that I built using 65 CALB CA100FI cells in series with a Prestolite MTC4001 series DC motor and a Soliton 1 controller. The battery amps rise with RPM, but it has full torque available almost immediately at stall. It is the controller that is providing maximum current at take off, not the battery. The battery's power demand rises to match the controller's power demand plus any losses as the RPM rises. I have the battery current capped at 400A, but the controller is set to 700A. If I punch it at a stop, the battery current is not immediately pegged at 400A. In fact, even accounting for the 0.7 second delay before peak torque is realized from the controller output ramp function(set to 1000A/s), starting out in 3rd gear, the battery current is still not at 400A even after 2.5 seconds, even though it's already been making peak torque for almost 2 seconds and I'm already over 30 mph. I have to rev that motor up under load to get the battery current draw to match its max setting via the controller, and thus max power, but the motor itself is causing the car to pin my ass in the seat well before that point with the tires clawing for traction the entire time.

I could set my controller to 1000A output to the motor, without changing the max battery current draw, but then I'll eventually break things... not that I use the car much, since it isn't even road legal nor do I have a license to legally drive it. It's had less than 20 miles placed on it thus far, mostly in a nearby cemetery or some side streets when there's no LE to ruin my fun.

[JackFlorey]

“Maximum Torque” from a DC motor requires maximum current.
Maximum current implies maximum demand on the battery supply

No. You are confusing current with power.

If a motor/controller system is well designed, then at low speeds pulse widths will be very low to deliver maximum torque. You will be delivering maximum current to the motor, but since you are at (say) 10% pulse width, the controller is drawing only 10% of that current from the battery. As speed increases and back-EMF increases, the controller will require wider and wider pulse widths to supply max current to the motor.

[Hillhater]

.....The battery's power demand rises to match the controller's power demand plus any losses as the RPM rises. I have the battery current capped at 400A, but the controller is set to 700A. If I punch it at a stop, the battery current is not immediately pegged at 400A. In fact, even accounting for the 0.7 second delay before peak torque is realized from the controller output ramp function(set to 1000A/s), starting out in 3rd gear, the battery current is still not at 400A even after 2.5 seconds, even though it's already been making peak torque for almost 2 seconds and I'm already over 30 mph....

TTc’r...respect your personal experience, but how are you actually measuring your “peak torque” ?
There is extensive data posted from NASA tests on the Prestolite MTC4001, and whilst they do not run it down to a full stall (?), the data clearly show the controller input current increasing with torque loading as the rpm reduces (from 4000 down to 250 rpm) . Maximum torque is at the lowest rpm , as is the maximum current draw and power input.
https://www.semanticscholar.org/paper/S ... 5/figure/4

[The Toecutter]

TTc’r...respect your personal experience, but how are you actually measuring your “peak torque” ?
There is extensive data posted from NASA tests on the Prestolite MTC4001, and whilst they do not run it down to a full stall (?), the data clearly show the controller input current increasing with torque loading as the rpm reduces (from 4000 down to 250 rpm) . Maximum torque is at the lowest rpm , as is the maximum current draw and power input.
https://www.semanticscholar.org/paper/S ... 5/figure/4

That chart you list pairs the motor with an outdated and highly inefficient controller from the 1970s that does not pulse width modulate the signal as well as today's tech. The combination's extremely low efficiency at lower rpms is very telling, granted, this is not a highly efficient motor to start with. If I had the money, I'd upgrade to a synchronous reluctance motor/controller setup.

My controller sets my motor voltage limit to 165V, twice as much as what is shown in the chart you list. I have not dynoed the car, so I don't have a real world measurement of peak torque, but with a series DC machine, torque varies as a square of the armature current, and the maximum torque possible is inversely proportional to rpm(the higher the voltage applied, the higher of an rpm that the motor can make a given amount of torque), and my controller is set up to allow peak motor current all the way until the max power output settings on the controller are reached(based upon max battery current, but the motor curve itself is also influenced by max motor current and max motor voltage via controller. Once motor voltage rises to the limit is when motor current and thus torque has to drop off). I only have my gauges set up to measure speed(mph), motor rpm, battery current draw, battery voltage, and motor temperature, so I have no way to compare motor current(and thus torque) and battery current together. I have the max current output from the controller to the motor set at 700A, and it is reached as soon as the ramp function(set at 1000A/s) allows once the accelerator is floored, but I can definitely feel the acceleration drop off a bit after about 4,000 rpm or so. When I get all the bugs for this car worked out and actually finish it, I plan to increase max current draw from my batteries to 600A to get a bit more peak power and extend the max rpm for the peak torque part of my motor's performance curve

I did make a spreadsheet to simulate my setup. My real world experience appears to match it, even if I may not yet have had a chance to apply the scientific method to get some hard numbers. I don't know when that will be though, as I've repeatedly spent my savings keeping my mom from losing her house, and she's disabled and unable to walk or work. Although I have close to 10 years of experience as an electrical engineer, I'm currently stuck washing dishes at a restaurant for minimum wage at the moment, so getting this car ready could easily take years... Finishing my electric velomobile will cost a lot less time and money and I currently use it on a daily basis, so that has been my focus as of late.