If they really wanted the sport to succeed in overtaking F1 as the premiere racing championship, FE needs to massively raise the power ratings to encourage what in F1 is often known as "cheating". I'm dead serious. They need to cheat. Cheating means innovation, invention, intelligent designs, creativity... The teams need to become manufacturers of their own batteries, motors and everything else like in F1 so they can start cheating like crazy... And then the general public gains from this and road cars get better.
Maybe having formula racing could be little benefit for EV company, because the huge amount of cost for research but lower impact they still need to focus on essentials like production scalability, lowering battery cost and increasing range or capacity, rather than branding, the demand is higher than their production capacity right now Compared to ICE car, EV has different components, means there is no industry best practice, they still need lot of research on optimizing thing, create production method by themself, to increase production output Meanwhile EV is gifted with that high rpm feature, they did not lack in speed or performance, thus branding is not their priority concern right now some EV manufacturer like lucid air and tesla race their consumer car on laguna seca, that 1:30 lap time that normally can only be achieved by an ICE super car like mclaren P1, that is proof that they dont even dont need much effort on branding,
@Allen Loser I think everyone knows that. I do at least, I've been watching since the first race. More power =innovation, ingenuity, greater speeds, more fans, more money and faster development. It's good for the sport.
@@flmworks Thank you for your input and thoughtful, detailed reply. You make a compelling argument, though I respectfully disagree with your assertion that there is little benefit and little application. Disc brakes, active suspension, sequential gearbox, aerodynamics, steering wheel functions, engine mapping, kinetic energy recovery, crash crumple zones, automobile sensors, active computing and data processing (software adapted from F1 for use in ambulances and hospitals to predict heart attacks), tire research, Kevlar research, carbon fibre weaves, carbotanium, materials sciences (information which is supplied to aeronautics industry and NASA), engines and how to get the most out of them, turbos connected by shaft to both recover energy and use energy off throttle for instantaneous power without lag... This list goes on for a long, long time and I've barely scratched the surface. The point I would like to drive home is that experimentation leads to invention and innovation. It's a worthwhile investment because if just ONE invention or innovation has application somewhere else in the world, it creates new revenue, new industry and improves the world. I believe that Formula E is in its infancy right now, I also believe that the concept of it is being mismanaged -it's not sexy, exciting, mind blowing and it doesn't make people nearly as excited as they could be... And that's because there really isn't a reason to get excited. What you find in Formula E, you can find in a road car... What if that wasn't the case? What if Formula E had rules that attracted manufacturers, inventors, innovators, investors, the world's greatest drivers? What if a Formula E Grand Prix ran the same distance as Formula 1 -but the cars were twice as fast? How many people would want to watch that? How many NEW things would be invented along the road to get to that point? When Formula E is faster than Formula 1 and can run just as long and just as reliably, road cars will improve. What we have in the world today, the best EV's have nothing on what the future holds. Imagine a 10% improvement in every area of development.... That's not just 10% better, that's a quantum leap forward because it's in every category of design and engineering, every single part is 10% better and this will have massive impacts on improving production, efficiency, handling, suspension, weight, heat management, etc. I get that electric cars are really, really fast and they're quite honestly cool as hell -but they're nowhere near to achieving their full potential. They're in their infancy -so are batteries, so are motors and so is charging and efficiency. So I think Formula E needs a massive amount of funding and marketing, it needs to work shoulder to shoulder with scientists and manufacturing so that things which haven't even been dreamt of yet can become reality... I remember what cell phones were like before the first true smart phone was introduced by Steve Jobs, the Apple iPhone... The many inventions and innovations, creative application of existing technology and minor improvements along with a hell of a lot of forethought and imagination and quite honestly, the technological visionary intuition of Steve Jobs (who was basically a prophet of technology) has changed the world forever. Look at the internet and how that has grown and become a dominant force not only in the day to day lives of nearly everyone in the developed world, but it massively contributes to the GDP of countries. When it first started, it was for nerds. It was very slow, it literally connected only two computers. Now look at it. I could go on all day about why innovation is so important, but in terms of Formula E: in order to succeed as a sport, it needs to become a crazy place full of brilliant, crazy people who make and innovate new things; a place where inventions are dreamt of and tested and innovated, a place with a wide open rule book where those who dare, win. They have an opportunity to radically change the future... Only they're not doing that because their rules are choking the sport to death. Let them cheat!!
After riding my e-bike over 1,500 miles in the last 5 months, I'm thankful to have retained the 8 gears on the rear wheel. One thing I've learned is that low speed with a high-powered electric motor = HEAT! And also big power drains from the battery. By starting in a lower gear on my e-bike, I can keep the motor turning at a relatively higher RPM, which is better for both the motor and battery. Then as I increase speed I gradually shift through the gears. Works awesome.
Thank you, exactly what I wanted to say. Consumer companies have promoted these ideas to gain more profit and centrally control others. Removing the gear system will make the motor larger because it will require increased winding coil, the use of rare earth materials in order to obtain strong magnets, an increase in the radius of the motor, in addition to the increased use of complex, sensitive electronics in a way that they are not needed, all in order to compensate for the removal of a very important and simple system. gear system increases the efficiency and power of the motor with less energy consumed. Removing a simple system like that will also reduce the life of the electric motor and battery, as you explained. Most of the heat generated in electric motors is due to the coils that convert electricity into magnets. It is known that electromagnetic coils lose a large portion of their energy in the form of heat.
FIA Formula E Championship Loosen up the regulations already. Allow for much more Wh of storage, your batteries are a joke. I wanna see half meter in diameter rotors and four wheel burnouts at 300 kph.
ABB Formula E I've greatly enjoyed the series. Thank you for helping to push the technology. We need racing for the innovation & to break things for the good of progress.
When making video's it seems like it'd be simple to say one thing, then have the conversion text overlay making it relate-able to a wider audience. Not sure why video makers just don't throw that in.
The persistent use of crappy imperial is the reason why american are scientifically illiterate compared to the rest of the civilized world. They are confused and simply can't compare, understand and are lost when reading scientific and technical articles. Can't even read a map or compare price per unit in the supermarket.
Thank you, thank you, thank you for explaining this so well. For years I've been sick of people saying that electric motors produce full power and efficiency across the entire RPM band.
How exactly do electric motors deliver full power instantly and stays constant over the rev range, whereas combustion engines gain/lose power/torque as rpms increase?
If the electric motor does not get full power right away, but gradually accelerated . is it still full torque from the very beginning or do you have to floor it for full torque? I have a rc car with a electronic speed controller and when i barely press the radio it barely has any force...couldn't that be applied to electric cars so they can use transmissions?
Good video, one suggestion for you is to explore how could more gears coupled with smaller electric motor could help to mitigate the range issue on electric cars.
good explanation, how this works with electric cars. Most people think that electric cars have gears. People calling the drive mode switcher a gear shifter, but it's not, because there are no gears. Also somebody told me already, that she don't like that low noise electric car, because she will not know, when to change the gear ;-)
It's also worth noting that the effective "gears" are created by changing the winding geometry of the eMachine, where you trade off maximum torque vs rotational speed for any given power value. A higher number of turns means more torque (more ampturns) but also means lower maximum speed because the KE of the motor is similarly increased. However, as it's the inductance of an eMachine that fundamentally limits it's ultimate power capability (for any given supply voltage), and inductance increases as the square of the turn counts, you'll find the trend for maximum power eMachines to be towards, smaller, higher speed, lower torque architectures, and these could/will need gears in order to meet the low speed (and zero speed) tractive effort requirements
Oh right, I forgot you still use imperial for distances and speeds (and a few other things I think?). The majority of the world does use metric though.
What if it was applied in a heavy duty towing application? Wouldn’t multiple gears be feasible for torque multiplication at lowers speeds, also would a higher gearing yield more range out of the battery? Stressing it less at higher speeds should lower power consumption right?
I don't think it's necessary for towing, but i also think that a second gear with a decent gap, could drastically enhance the range of EVs at highway speeds.
Anyone who owns a TESLA will love that you do not have to take your car to the shop and leave it for a few days for any minor repair. Tesla Rangers will come to your home or business and do the repair where the car sits. They can repair 90% of any issue without needing to go to the shop. If you do need the car to go to the shop, TESLA puts you in the newest/best car they have on the market, as a loaner while they fix your car. Elon wants the loaner to be better than the car they are fixing.
Some EVs (like the BMW i3) go have simple clutches to disengage the motor from the drivetrain when a sudden shock is detected to prevent damage. So whenever I go over the crest of a hill at high speed in the i3 and get some air the computer engages a clutch and the motor is isolated from axle. If you are not prepared for it it can be a bit shocking because you obviously lose regen braking at the same time since the motor isn't connected. So after it contacts the ground again the car freewheels like it's in neutral for about a second and then the computer reconnects the motor. There was an issue also when the rear wheels of the i3 were off the ground... and accelerator depressed fully the wheels would speed up to very high rpm in that fraction of a second with the lack of resistance and when the wheels hit the ground suddenly slow... A few of my fellow "enthusiastic" i3 drivers had the motor mounting bolts loosen due to the repeated shocks and that had to be fixed in a recall by getting the clutch to disengage earlier.
That was great. Another great way to show this is: drawing a graph that show on a combustion engine at what speed is the car going at each gear on top efficiency and another on the electric motor
Someone had asked me about this and as I started my research your notification popped up. Interesting... I just simply forwarded your video. As usual... awesome job!
I think you could have pointed out better one aspect that is in my opinion the key difference for gearing between electrical and combustion engines. A combustion engine might at best have a wide flat range of torque so you have at best more or less linear increasing power. An electrical engine on the other hand has almost constant power curve over the whole range and a corresponding degressive torque curve which is theoretically infinite at the start. The torque is more or less proportional to the current which needs to be limited and is limiting the torque therefore. Mostly only for that reason the full power is not there instantly and once the torque is not limited anymore the power curve is becoming flat even without a power limitation. And the maximum current is more or less proportional to the engine size and therefore weight. So having torque at low rpm is essentially a trade-off between engine weight and transmission weight (usually favoring a slightly bigger engine and passing on the multiple gear transmission). I am sure that is what you meant, but I think it might not have become clear to everyone watching the video.
I am a car guy and love traditional combustion engines, but electric-powered cars are outperforming them- just as cars were outperforming horse-powered transportation at a distant place in time. The future is efficient and torque'y, but completely mute.
Even as an engineer I have to say, I watch racing mainly because of the racing. The engineering is also nice, but the fun part is racing. And my answer was like that, because he said, that electric cars are outperforming petrol cars and my opinion on that is, that this will never happen in racing. Maybe on the streets but an electric car will never beat a f1 car over a normal race distance!
During my last days on active duty in the Army, I had the opportunity to learn to drive a diesel-electric locomotive. While it isn't gearing in the traditional sense, I learned that the locomotive starts out with the motor windings configured in parallel. The gives increased torque. When the train reaches roughly 30 mph, the engineer eases off the throttle, and the windings switch to series configuration, which provides less torque but greater speed. I don't know whether or not the Tesla truck uses this same principle, but I would expect that this would be a great advantage to help get the rig moving with a heavy load. It would also be advantageous for off-road vehicles that often need high toque at low speed. It would be similar to a two-speed transfer case.
No, the same load is being driven by the same motor. The only difference is an increase in amperage for more torque and a decreased voltage for less speed. However it may be easier if I say the wattage, the total measure of electric power, remains the same.
You could also think of the electric motor itself as the transmission, as is the case on many locomotives. On diesel locomotives, for instance, the traction motors generate very high torque when accelerating from a low RPM, and generate proportionally less torque at higher RPMs, thus outputting the same power at a wide range of RPMs. This effect is called motor stalling, and it essentially causes the motor itself to act like a continuously variable transmission. Hence the motor acts like a low gear when accelerating from low speed, and acts like a high gear as it reaches the desired speed. The reverse of this effect allows the motor to act as it's own brake, which is called dynamic braking, or regenerative braking when it's used to recharge the battery during deceleration. This is why diesel and electric locomotives are able to generate the huge amounts of torque required to start massive freight trains, whereas steam engines have difficulty pulling large trains at low speed.
+Engineering Explained So we know now why most electric cars don't need gears in normal applications, however would multiple gears improve higher speed applications? Even if it were a 2-speed or CVT. Most EV owners are well aware of the heightened power consumption when sustaining high speeds. In your usual Leaf or Renault Zoe, the motor is spinning at 7500 or 8000 rpms. Cars such as those also start to experience a loss of available torque at speeds of +50 mph which makes overtaking awkward. Aside from the well known case of early Tesla Roadsters destroying their 2-speeds, should every OEM EV be limited to be a 1-speed.
anytime you convert power through differential gearing, theres a power loss. Combined with the added weight that a transmission adds and you lose any efficiency you would have gained.
" Cars such as those also start to experience a loss of available torque at speeds of +50 mph which makes overtaking awkward." It is not about the loss of torque but a loss of available power.
Tesla Model S and X can achieve 155 mph... how much faster would you like to go in an off the shelf vehicle? For racing applications it is totally different.
Does electric motors electric efficiency decline with speed? I mean, does it consume more electricity to drive the same electric motor at 20k and at 10k RPM if both are are the same RPM (like 170 kW in Formula E)? I had the opportunity to work with a 11 kW motor (says the manufacturer) and I had it working at up to 48 kW but just after the peak power it just started dropping (a lot) but I still had the engine sucking up 48 kW electrical energy. I'm just wondering if that was just the controller that wasn't properly set up, if there was too much friction losses or if the electric motor itself becomes less efficient.... Could that be a reason to have multiple gears so you avoid running in that high rpm low efficiency state?
Sounds like you over-saturated the coils. You hit a point where throwing more electricity at a motor just produces heat, not power. You should be careful, heat can destroy a electric motor fast. Excess heat will demagnetize the rare earth magnets in the motor.
You can also use different windings on an electric motor as gearing... resistance is the reason for gearing to begin with so it should not be a surprise that windings are used as gears for efficiencies of fuel/energy
If you use two windings, of different lengths, you really have three "gears" 1=short winding, 2=long winding, 3=both windings in series, with two SPDT switches (and something to prevent both switches being set to the same tap point, which would short out the circuit.
So overall, would there be any benefits to have a CVT in an electric car? I ask because if you're going to have any gears at all, why not have it be the most efficient type?
Chaotic-Good Antinormie CVT has big losses and whole point of cvt is to keep the engine at constant power/engine speed at peak efficiecy to neglect own loses. Electric motor by design make constant power over most of their rew range. Simplest reduction gear is most efficient way to trade frequency for torque.
A transmission has a efficiency of around 85-95%, depending on the rev. So in you can save 30% power during acceleration for about 30 seconds, but loose 5-15% during crusing for the next 10 min you are way worse off with a transmission
I think with a gearbox an electric car could use much less power to keep the car in speed at -for example- 120km/h, thus the range of the car would multiply.
not really, as you only use power to get the engine to certain rpm (a lot of work), then to keep it at that rpm (not too much work), this is why cars are economic when they keep the speed but consume much more fuel when accelerating. Most of energy is used to spin the wheels, not the motor and to lauch a car in specified direction, not to spin the engine itself, so it won't have any great impact on range.
I agree. Most modern electric motors run on 3 phase alternating current with a frequentcy converter, and i was thaught that when the frequenty increases (aka let the motor spin faster) the inpendance also increases therefore losing efficiency. So if there is a gearbox the engine can rev lower and have less internal resistance.
The main reason to have a gearbox on a electric motor is to accelerate faster and to climb hills easier. When a electric motor gets bogged down (like on a steep uphill climb) it can heat up very fast and destroy itself. Not to mention it's much less efficient running at low rpm with high load. Better to use a gear ratio to turn it into high rpm and low load.
Nice final frames with the rain :) I have an 2016 Tesla P90D and it surely feels like it can have a second gear engaging from 70mph on. While the car has an enormous amount of power in the low speeds, it loses that power advantage to gas cars after 70mph. And yes, I do acknowledge that this means more complexity and more strain on the battery. But just imagine the crazy acceleration up to 150mph :)
That is what I am saying as well. I don’t own an electric vehicle but take that Formula-E car for example. It does 225 kph with the electric motor and just 1 gear. If you were to just slap on ONE more gear then you could easily get 375kph or maybe 400 kph out of the car. I understand that the electric motor is high revving and all but you can’t tell me that, speed-wise, it wouldn’t benefit from just 1 more gear!!! Crotch rockets oftentimes redline at or around 15,000 rpm and they have more than 1 gear. I know it’s apples and oranges but still. I would like to know your thoughts on my opinion, if you don’t mind.
Can you do a video which explores homemade diesel fuel? How is it made?... Does it have any negative affects on modern diesel cars like a Mercedes BlueTec? Thank you so much, love your videos and all the work you put into making them!
I’ve seen two fuel cars that start on regular diesel and once warmed up switch to used filtered cooking oils. Interesting. The exhaust makes me hungry for fish and chips. Seems to work alright. It may not work really well when it gets cold outside as the bio diesel may gel up. I saw that happen to a huge barrel of diesel used to run a diesel electric power system. It was fall and winter grade diesel was supposed to be delivered and accidentally got summer diesel. After a short tome the lights went out. It’s really hard to heat and drain a 5,000 gallon diesel tank. Tough lesson learned.
I have a question. How much electricity is actually being consumed at the various speeds of the motor? Say, 5000, 10,000, and 20,000? I would think highway driving, even with an electric motor, that keeping the RPMs low would be just as fuel conservative as it would be for a gas engine. And I would think if an electric motor is good for torque and very low RPMs, why not gear it to run at low RPMs with a kinetic reservoir like a flywheel. Then there's the argument of which is better, volts or amps.
Well, you've certainly got the ideas down! The biggest problem is cost, and complexity, not the theory behind it. It's a given that a motor performing more work will consume more power, gasoline or not. An electric motor has more spots where it can remain efficient compared to a petrol motor, but of course running it at maximum power will use the maximum power it is capable of using. Kind of how maximum brightness on a phone eats up a bit more than turning it down. Not by too much, but still a percentage. Of course, ultimately in these independent lab scenarios, weight and complexity bring up more and more questions about how we could go about new technologies to further improve the electric motors. I say we are still in the infancy of what kinds of new technology/innovations are available to us, but perhaps we'll have another "Roaring 20s" of our own after coronavirus!!
Electric motors do not really use more energy in high rpm. The power consumption is because of the load on the motor, not the speed of the motor. If you step down the rpm via gears, the load or force on the motor increases, increasing the power consumption greatly. Since it is efficient in all rpm, this would have no benefits. Electric motors can stick,slip and melt at low rpm, so it may even be less efficient or dangerous.
Hey jason! I tried to make a suggestion on your website, but was unable to due to a glitch in the system. I just wanted to recommend a video in which you explain the benefits and shortcomings of polyurethane bushings, spherical bushings, and standard rubber/OEM bushings in a suspension. I once had a very experienced automotive engineer tell me that he prefers rubber bushings and that it's a common misconception that poly bushings are superior, but his explanation was too complex for me to comprehend... I understood that the principle was that poly bushings limit movement in the suspension components, leading to less responsive handling, inaccurate alignment, and reduced mechanical grip. I was hoping you would be able to explain this more in depth and in a manner that a fresh ME student would be able to grasp, and I'm sure many others would appreciate the insight. Thank you!
And another thing from my observation is that the gear ratio can be chosen to go close to the maximum acceleration possible the limiting factor being grip. For example I’ve calculated for bmw i3 a 0.54g acceleration from the motor and I figured this roughly matches the grip of the tires given that they are not super sticky and the weight distribution is 50/50, rwd because the friction coefficient is around 1 and 50% weight on the axle means a value around 0.5. This confirmed when you drive the i3, you feel the tires are slightly below the traction limit because they squeak a bit. With a normal (ice) car they would make a short ratio and give you more wheel torque than needed to make up for the clutch slip, to have extra traction when fully loaded, and to make them drift, but sometimes it becomes difficult to control and you loose traction (see m3 vs i3). But tesla with awd goes with faster acceleration but the power is much higher also.
I could see a use for a low crawl ratio for 4x4 vehicles. I single planetary could be attached at the front of the motor(s). It would be locked up for road use, but when climbing steep hills or rocks, you could unlock it for an extra 4:1 or so. If the conditions of the shift are controlled, you could do it to multiple gearboxes at the same time if you had independent axle or wheel motors. You could also use it to boost motor speed during regenerative braking to put more power back in the battery.
Assuming the widths (which affects grip way more than circumference as far as I'm aware) of the wheels stays the same (let's say 8.5") how much quicker would going from a wheel diameter of 18" down to 17" or 16" make your vehicle accelerate? The smaller wheels (in theory) should act the same as having a higher final drive which will effectively increase acceleration and decrease top speed in each gear (and top speed in general).
Instead of explaining why electric motors have no gears, explaining why ICEs have gears would be way better, because former is more intuitive anyways :) But I'm sure you explained the latter already so it's still nice to have videos about electric vehicles. I love to see rising popularity of these vehicles as a power engineer.
Tesla is fastest accelerating production car in market. It doesn't have highest top speed though due to software limited top speed. Mostly because batteries overheating so Tesla has to reduce speed down. Roadster might be able to go on high speeds if Tesla will fix overheating issue
Great explanation! I am a fan from Brazil and it is very satisfying to watch this video. I am also a eletronics engineer student and I am currently working with a project for university about eletric car and I had this very question about gears in eletric cars. Thanks!
Again, it's not necessarily worth the efficiency losses that go into adding a geared transmission. Also adds weight and complexity. Electric motors are efficient across a wide range of RPM, so adding gears could potentially mean reducing efficiency.
With a synchronous motor the efficency doesn't change as much with rpm as a combustion engine does. So the efficency gain with more gears is not as big as the gain on combustion engines. But it makes the car heavier, which decreases the efficency, which smallers the gain even more. And of course it costs more, and the price is beside the range one of the biggest problems for electric cars at the moment.
Great video. I’d like to suggest doing a video on tires and proper rotation and tread wear guidelines. For example, I’m having a disagreement with coworkers on replacing 2 or 4 tires at a time on their front wheel drive vehicle. I maintain that if you are only replacing 2 tires you need to make sure those new tires go to the rear of a front wheel drive car to prevent over steering. They think new tires or best tread tires should be in the front because it’s the drive tires on front wheel drive. I try to explain that regardless of front wheel, rear wheel, or all wheel if you have miss matched tread depth tires the best 2 should be on the rear to prevent oversteer where the rear end lets loose which is harder to control than under steer. Anyone with an opinion please chime in? Thanks!
I know this is an old video, so you may not see this comment. But the question I have always had about gearing and electric vehicles pertains to efficiency, in terms of what we call gas mileage in an ICE car. I understand that low gears are not necessary for electric vehicles to get adequately started moving, but couldn't there be some efficiency gained in terms of 'mileage' or range by giving them overdrive gears? If you had some very aggressive overdrive gears could you not save energy and increase the range of the vehicle by allowing the electric motor to hum along slowly while keeping the vehicle steadily cruising at 60-80 MPH?
Why do electric cars need brakes at all? Motors are capable of applying torque equally forward and backwards so surely they can slow down as fast as the tires can grip.
For emergency situations. And depending on the state of battery charge (completely full or completely discharged), the regenerative braking might not work at all.
Surely it is wrong. Decelerating at grip level from high speeds needs much more power dissipating(recuperating) than regular electric motor can provide.
0:56. Everything I needed to know said in about 10 seconds. An electric motor has a single gear calculated for its top speed but has the same torque from 0rpm up to its max so it’s useful at all the lower speeds.
Battery lifespan is a major concern, but I wonder what the lifespan of the electric motors will be with them possibly spinning at very high rpm a lot? What about the magnets in the electric motors, will they degrade over time? Time will tell.
Electric motors last, generally, far longer than ICE for a simple reason. The only part that wears out is the bearing that allows the rotor to stay in place. Depending on the quality, it can easily last over 1 million km. What will wear out way before that will be the transmission.
I think once they can figure out a battery tech that can survive far more charge/discharge cycles and maintain a good power density than current lithium/lead acid batteries we will see a HUGE EV explosion. But until then dinosaur powered cars will stay the king.
Magnets do wear out with extreme heat, nothing that liquid cooling cant solve...but only dc motors use them , ac motors dont need magnets, they are basically opposed pulsing electromagnets..
Jordan Anderson Check out Jay Leno's Baker electric on UA-cam. 100 years old, still works perfectly. Batteries are new of course. but the motor will last generations. Our whole industry runs off electric generators and motors. They will last a looong time even at continuous duty. You can design any part to last as long as you want, but there are compromises. Modern batteries will probably last a million miles in a car. The batteries will out last the car and owner.
It'll be interesting to see if multi-gear transmissions ever catch on in production EVs. From what I understand, it's really just the cost of materials holding them back from being a reality (need VERY sturdy components to handle all that torque) - but in a road car, the benefits are also minimal. The original Tesla Roadster was supposed to have a 2-speed automatic, but they could never keep it in one piece... ultimately, it didn't matter. Not having any gear changes is also one of the things that makes the experience of driving an EV unique. A lot of the early automatic transmissions in the 1940s had the same selling point - no gear changes whatsoever on an original Buick Dynaflow. Back then, there were some people who thought the Torque Converter alone would be sufficient as a manual transmission replacement... turns out people weren't willing to part with all that efficiency and performance. But those early automatic Buicks are definitely a much, much different experience to drive than pretty much all of their contemporaries. Love EE, love Formula E - keep up the great work homie.
Well a human has a very narrow power band compared to an electric motor, so we really need a few gears on our bikes to make them more practical. There are a few bikes that doesn't have multiple gears, one of them being the "fixie" and I think there are some velodrome race bikes that has a fixed gear ratio. The fixie isn't really a practical bike, and the velodrome racers can't start without having someone help giving them a push. Other than those it's mostly children's bikes (and possibly BMX?) that comes with a single fixed gear.
Blahorga Slisk....If I can I buy today car for my daughter with fix gear sow she can start slowly and have speed limits...every beginners should have car with fixed gear or looked automatic with two gears :D
Fun fact: dual-motor Teslas (75D, 100D, P100D) have different gear ratios on each axle (but a single ratio per axle). The rear ratio is optimized for acceleration since the weight shifts back there during a launch, while front ratio is optimized for highway speed cruising and better regenerative braking, since the weight shifts forward during braking. So launching at a traffic light, you're in a rear-wheel-drive muscle car, but once you're past the on ramp you're in a front-wheel-drive economy car. On a highway, the rear axle is essentially in neutral until you're ready to pass that slowpoke Dodge Challenger. Best of both worlds, which is why the dual-motor configurations actually get better range than the older RWD only models.
pSyk there was a Chevy S-10 I seen once that was converted to EV, but it also retained the 3 pedals and 5 speed. Wonder what that would be like to drive, I'd bet if you actually shifted it'd be very fast, as you can even get decent acceleration just in 5th gear alone lol
Some of the FE cars have a gearbox for better torque management...but it's flappy-paddle operated (stick would take up too much room in those cockpits).
You ask a question, but answer another one. As you explain things really effectively and comprehensively I still feel unsatisfied, because I'm really eager to learn why electric cars on the market have no 2nd or 3rd gear to allow them reach higher, than 160km/h, speeds. I only know that Tesla, when developing the first Roadster, had massive problems developing the gearbox hence they eventually gave up altogether and released a car with just 1 forward gear. I hoped you'd actually tell more about these difficulties - why is it more challenging to create a gearbox for electric cars (Tesla tried with vendors for 5 years before they concluded they failed).
Jason, have you ever considered automotive engineering since you majored in mechanical engineering? I saw the video on why production cars haven't reached 300 mph and I wondered if you ever considered working in that type of field to help improve the automotive industry or help break records such as the 300 mph milestone.
Any car going above 350 km/h will go through a full tank of fuel in around 7 minutes. I'm not even low balling the number, that's how much energy is required to sustain the speed due to air friction. It's not practical because it wastes too much energy to travel just a short distance. At low speed the energy per km drops.
electric vehicles use electric motors with iron core on the stator. why not use ferite core instead of iron. ferite core transformers for example are much cheaper, more efficient and many times lighter than iron core ones. the only difference is the magnetic flux those core types can take before saturation and the frequency you can use them. ferite cores saturate at lower magnetic flux, but can take much higher frequency signal before having hysteresis loss. engineers might say the problem is the motor would reach much higher rpm and would have much less torque, but if you make it have 10 phases instead of 3 and have 100 sectors instead 9 it would have the same torque, but higher max rpm and higher efficiency
But toque... you can put a lot more torque into tarmac higher gear ratios. The "acceleration" will be much higher, if a higher gear reduction is used at the beginning. And then switched to "cruise mode" to keep it going. Can come handy in electric jeeps - for pulling heavy loads. Can come in handy it traffic jams for... no, in traffic jams high torque causes jerky movements which merely increase the risk of accident, lol.
Because they aren't (yet) built in high enough volumes! But that's changing and changing fast. the next ModelYear platforms are likely to achieve cost parity with ICE, and the one after that will be cheaper!
If you have a motor and controller that controlls the stator field current then you can have a single tall gear ratio and manipulate the field current to get more torque at lower speeds, and have a high speed range at constant full power output. This is typical for a DC motor with brushes and a separately excited field (not using a permanent magnet stator field). For full acceleration the motor can output maximum torque at lower speeds with the stator field at full current. When the speed has reached the rated speed for full power the system goes into the constant power region of operation. As the speed continues to increase, the field current starts to be lowered while the armature voltage stays at it's maximum. While the speed increases the torque output decreases (as the field current is lowered), but the power output can remain constant at full power as the system accelerates up to the maximum motor speed (or some other design limitation). In the constant power region it has a similar effect as having a CVT transmission.
Engineering fail. HP = RPM X torque. An electric engine at 10,000 RPM produces ten times the power that its does at 1000 RPM. Obviously, you need a gear of some type would be highly advantage. In reality, most electric motor's use a drive scheme that drives the poles in a way that gives the effect of a mechanical transmission, but in an electric way. This is done by selecting the way the poles of the motor are being driven. Many poles = lower speed = more torque. Fewer poles = higher speed = less torque. No transmission required, because it can be done electronically. Look at it like this. If a electric car has 600 HP at 10,000 rpm and 100 MPH, then it only has 30 HP at 500 RPM and 5 MPH, when it is getting started. But we all know electric cars are quick off the line.
While you are correct in an EV there are a few other factors. The battery for example will have a maximum current discharge limit. Power = Voltage x Current.
One question, how electric car move from 0 speed if it don't have power? I think this way of thinking is good for gas car, but not work for electric cars.
Sędziwój Poljak:) Power is product of speed and force. 0 rpm zero motor makes 0 power, but it has max torque or force. It acelerates with constant torque until it reaches max power. When it reaches max power, torque start to drop, but product of torque and revs stays constant, so it makes constant power. It max rews are limited by internal structure and by overrewing motor would fell apart.
Fun fact: the BMW i8, which was shown in the video and is Formula E's Safety Car also uses 2 gears on it's electric motors. But it's a hybrid, not a pure EV. Its ICE has a usual 6-speed transmission...
I know you guys avoid customary units like the plague and metric units make more sense, but for the ones who still use the customary system in daily life, it would be nice to give the conversion in parenthesis next to the metric unit. It doesn't even have to be verbally said. Just written, so us customary folk can conceptually understand on a more relatable basis. Thanks.
Alex O. Haha but he's right they should have... Remember last time someone added metric units to help you and you didn't have to Google the data. How you thanked them. It's the little things in life you know.
I think you don't really need the imperial units to understand why a electric car doesn't need more than one gear. I guess it would be nice for you to immediately know if a formel e car is fast or not or how lare the tires are, but the math behind it keeps the same. And if the cars topspeed is 100 or 140 miles/h is, as my professor would say, trivial.
XilefR Sure, I don't _need_ it. The concept is simple enough to understand regardless of the units used, but it's nice to see a familiar number next to the foreign one. Besides, he says, "...what if you want to go 20 km/h?". People who use km/h know that's like a brief human sprint speed while I'm here doing the conversion to also have a similar real world comparison in my head while the main idea is further explained. In the end its all about relativity and as a imperial unit user, *I literally cannot relate.* 😂
The ideal setup for a performance vehicle (and trucks) is exactly how rimac does it. Single speed in the front and dual speed in the back. This video also didn't show that electric motors torque and consequently power drops off tremendously at high rpm so a second gear helps for not only top speed but also acceleration after 90-100mph. For commuter cars, no, single speed is by far the best.
In a road car, an electric motor could greatly benefit from an overdrive gear for use at highway speed, right? Something to drop the revs down to something like 1500 or 1000 rpm at 70 mph. This would greatly improve mileage on long road trips.
Do any of the teams use electric gearing (as in variable frequency AC drives?) That way you can match your torque/RPM ranges without any mechanical gearing
Thanks very much. In the example you cited where the motor will be doing 20000 rpm at 225 kmph, if we use a taller gear to do same 225kmph at, say 10000 rpm, we can increase the range. Isn't it?
Great video, but it just make me more curious. With the advantages and simplicity of an EV drivetrains (like what's used in the Nissan Note E-power),.Why don't all vehicles use them? No matter where the electric comes from like a battery, or an ICE used w/generator (or 100s of other options that become available)? And why do most BEVs, use motors with just poor performance (just to keep the driver from using to much energy)? And I guess I'm later to the party since I just saw ur Series Hybrid Cars - Explained post.
A multi-speed transmission can allow for a smaller motor and a less powerful battery pack for the same multiplied torque to the road through the tires. The losses through the extra gears is negligible in comparison to a bigger ampere draw from the battery from a 1-speed transmission. There are well-published charts from battery cell manufacturers that show the discharge rate at different "C" ratings. There is also a trade off in batteries between building a cell for maximum watts hours per kilogram versus building a cell for maximum watts per kilogram. In Formula E the race is always a balance between speed and range. Mark Yormark
Would the 3 speed not also have an advantage in saving battery power, needing less torque saving battery power, as it is ultimately an energy saving contest still.
I have had this question for a very long time: how are 2 different power sources (an ICE and an electric motor, for instance, not necessarily spinning at the same speeds) connected together so that they can combine their outputs to drive the wheels? I've wanted to know about this since F1 introduced KERS and supercars increasingly turn to hybrid technology to overcome turbo lag. I've read that the MGU-K is connected to the engine's crankshaft but that's all I managed to find out. Enlighten me, please?
My Puch Maxi S Moped which originally has 50cc’s, has a 70cc Zylinder and bigger intake and outtake. And it revs all the way up to 11’000 rpm and runs about 55-60Km/h
When I was a kid I had a remote controlled car with 6 gears. If you put it in the gear with highest top speed it would be really slow to accelerate and you would use up the battery in 10 min no matter how fast or slow you did go. Put it in low gear and you could drive for a hour. If you did go for the middle ground that gave ok acceleration and ok top spead you could drive for about 30 min and again speed did have little influence on how long time you could drive. As far as I know this still stands for electric engines of today at least to some degree (less then before because of higher max rpm), having gears will actually help on the economy as well as acceleration. Problem is to maker a gearbox that can handle the torque...
You know what ? You can do gearing inside motor winding as well, make two of them and in low speed make it in series, at high speeds make in in parallel do to back EMF. And surprise, you have gearing effect at some cost from electronics :) It will feel like VTEC :D:D one very well defined spot, just inverted :)
I'm curious how this will work with a semi truck. With all the added weight, wouldn't it be necessary to have additional gears? I drive semis, hence my curiosity.
gearing can definitely add performance to an electric car. there is a limit to how high you can rev. its more efficient to be at say 5000 rpm at 200kmh than being at 15000 rpm at the same speed. excess rpm is both bad for wear and tear and also it means extra loss of energy. If FE was held on F1 tracks like monza, 3 gear could help with top speed better than accelerating.
Depends on the rules and if the 170kW is electrical pack discharge / measured at the controller, the motor, or the wheels. If it's measured at the wheels then you would be crazy not to have a gearbox. If it's limited at the controller, be a tough call, and may be circuit dependant.
3 gears makes sense. Remember from stand still, you huge power from the battery to get going. Torque is not free energy. Gears can reduce stress on the battery and increase the range. Prius use tiny electric motors with cvt gearbox for more efficiency.
some main issues for road EVs with single gear: 1. relatively low top speed (most EVs have top speed of less than 100mph) 2. much slower acceleration from medium to high speed (50mph to 80mph) 2. significantly more energy consumption at motorway speed (a Tesla at 80mph uses significantly more battery than at 70mph) these are putting me off EVs (assuming charging won't be much of a problem in 2-3 years' time with 300kw DC fast charge and 100kwh+ batteries on most affordable EVs)
Now imagine Fast and Furious movies with only one gear. What will they do without dramatic gear changes every 10 seconds?
Adam K lol
talking about range issues and calculating the range by the actual power usage.
new FF series are not about cars so it doesn't matter.
Maybe switches to hook up emergency battery supplies.
Adam K Exactly. And not to mention unrealistic gear shifts. The cars they use must have 50 speed transmissions./s
If they really wanted the sport to succeed in overtaking F1 as the premiere racing championship, FE needs to massively raise the power ratings to encourage what in F1 is often known as "cheating". I'm dead serious. They need to cheat. Cheating means innovation, invention, intelligent designs, creativity... The teams need to become manufacturers of their own batteries, motors and everything else like in F1 so they can start cheating like crazy... And then the general public gains from this and road cars get better.
I... Honestly I have to agree!
Maybe having formula racing could be little benefit for EV company, because the huge amount of cost for research but lower impact
they still need to focus on essentials like production scalability, lowering battery cost and increasing range or capacity, rather than branding, the demand is higher than their production capacity right now
Compared to ICE car, EV has different components, means there is no industry best practice, they still need lot of research on optimizing thing, create production method by themself, to increase production output
Meanwhile EV is gifted with that high rpm feature, they did not lack in speed or performance, thus branding is not their priority concern right now
some EV manufacturer like lucid air and tesla race their consumer car on laguna seca, that 1:30 lap time that normally can only be achieved by an ICE super car like mclaren P1, that is proof that they dont even dont need much effort on branding,
@Allen Loser I think everyone knows that. I do at least, I've been watching since the first race.
More power =innovation, ingenuity, greater speeds, more fans, more money and faster development. It's good for the sport.
@@flmworks Thank you for your input and thoughtful, detailed reply. You make a compelling argument, though I respectfully disagree with your assertion that there is little benefit and little application.
Disc brakes, active suspension, sequential gearbox, aerodynamics, steering wheel functions, engine mapping, kinetic energy recovery, crash crumple zones, automobile sensors, active computing and data processing (software adapted from F1 for use in ambulances and hospitals to predict heart attacks), tire research, Kevlar research, carbon fibre weaves, carbotanium, materials sciences (information which is supplied to aeronautics industry and NASA), engines and how to get the most out of them, turbos connected by shaft to both recover energy and use energy off throttle for instantaneous power without lag... This list goes on for a long, long time and I've barely scratched the surface. The point I would like to drive home is that experimentation leads to invention and innovation. It's a worthwhile investment because if just ONE invention or innovation has application somewhere else in the world, it creates new revenue, new industry and improves the world.
I believe that Formula E is in its infancy right now, I also believe that the concept of it is being mismanaged -it's not sexy, exciting, mind blowing and it doesn't make people nearly as excited as they could be... And that's because there really isn't a reason to get excited. What you find in Formula E, you can find in a road car... What if that wasn't the case? What if Formula E had rules that attracted manufacturers, inventors, innovators, investors, the world's greatest drivers? What if a Formula E Grand Prix ran the same distance as Formula 1 -but the cars were twice as fast? How many people would want to watch that? How many NEW things would be invented along the road to get to that point?
When Formula E is faster than Formula 1 and can run just as long and just as reliably, road cars will improve. What we have in the world today, the best EV's have nothing on what the future holds. Imagine a 10% improvement in every area of development.... That's not just 10% better, that's a quantum leap forward because it's in every category of design and engineering, every single part is 10% better and this will have massive impacts on improving production, efficiency, handling, suspension, weight, heat management, etc.
I get that electric cars are really, really fast and they're quite honestly cool as hell -but they're nowhere near to achieving their full potential. They're in their infancy -so are batteries, so are motors and so is charging and efficiency.
So I think Formula E needs a massive amount of funding and marketing, it needs to work shoulder to shoulder with scientists and manufacturing so that things which haven't even been dreamt of yet can become reality...
I remember what cell phones were like before the first true smart phone was introduced by Steve Jobs, the Apple iPhone... The many inventions and innovations, creative application of existing technology and minor improvements along with a hell of a lot of forethought and imagination and quite honestly, the technological visionary intuition of Steve Jobs (who was basically a prophet of technology) has changed the world forever.
Look at the internet and how that has grown and become a dominant force not only in the day to day lives of nearly everyone in the developed world, but it massively contributes to the GDP of countries. When it first started, it was for nerds. It was very slow, it literally connected only two computers. Now look at it.
I could go on all day about why innovation is so important, but in terms of Formula E: in order to succeed as a sport, it needs to become a crazy place full of brilliant, crazy people who make and innovate new things; a place where inventions are dreamt of and tested and innovated, a place with a wide open rule book where those who dare, win. They have an opportunity to radically change the future... Only they're not doing that because their rules are choking the sport to death.
Let them cheat!!
@Viscous Shear lmao!! Exactly!!!
After riding my e-bike over 1,500 miles in the last 5 months, I'm thankful to have retained the 8 gears on the rear wheel. One thing I've learned is that low speed with a high-powered electric motor = HEAT! And also big power drains from the battery. By starting in a lower gear on my e-bike, I can keep the motor turning at a relatively higher RPM, which is better for both the motor and battery. Then as I increase speed I gradually shift through the gears. Works awesome.
If your motor is an induction or bldc one, it shouldn't heat up at low speeds like that. Maybe it's a common dc motor.
@@DragonOfTheMortalKombat I have no idea but I still have the bike and it has over 10,000 miles on it now.
@@Patrick94GSR Commonly, if it's two wires and you power it by a battery and a very simple controller, then it's a brushed DC motor.
@@concorde837 The BBS02 (and BBSHD) mid-drive e-bike motors are in fact, brushless motors.
Thank you, exactly what I wanted to say. Consumer companies have promoted these ideas to gain more profit and centrally control others. Removing the gear system will make the motor larger because it will require increased winding coil, the use of rare earth materials in order to obtain strong magnets, an increase in the radius of the motor, in addition to the increased use of complex, sensitive electronics in a way that they are not needed, all in order to compensate for the removal of a very important and simple system. gear system increases the efficiency and power of the motor with less energy consumed. Removing a simple system like that will also reduce the life of the electric motor and battery, as you explained. Most of the heat generated in electric motors is due to the coils that convert electricity into magnets. It is known that electromagnetic coils lose a large portion of their energy in the form of heat.
Great video; thanks for dropping by. See you next season!
FIA Formula E Championship Loosen up the regulations already. Allow for much more Wh of storage, your batteries are a joke. I wanna see half meter in diameter rotors and four wheel burnouts at 300 kph.
Not the place to stage complaints.
ABB Formula E I've greatly enjoyed the series. Thank you for helping to push the technology. We need racing for the innovation & to break things for the good of progress.
Approved
OK boomer
Thanks for using the metric system.
aullik. Your gratitude is equal to my disgust.
When making video's it seems like it'd be simple to say one thing, then have the conversion text overlay making it relate-able to a wider audience. Not sure why video makers just don't throw that in.
Max R why are you disgusted by it?
The persistent use of crappy imperial is the reason why american are scientifically illiterate compared to the rest of the civilized world. They are confused and simply can't compare, understand and are lost when reading scientific and technical articles. Can't even read a map or compare price per unit in the supermarket.
@@MR-nl8xr
Did you know that electricity is only measured with SI? Coulombs, Watts, Joules, Volts, Amperes, Farads are all metric.
Feels like I just watched a Discovery Channel show! Awesome editing and voice over. This is a must see video.
+u9Nails appreciate the kind words, thank you!
That must be the most quiet car race on earth
Skøut no it's still noisy. Think jet noises.
Mustafa Hasan not really its just the sound of the tires and cars moving through the air
Nah, electric motors are still louder than wind noise. Search for Formula E sound on YT.
no the motors make sound, watch Formular E videos.
Manuel Fischer it's actually the gearbox that make all that noise but yeah they sound cool. 😊
Thank you, thank you, thank you for explaining this so well. For years I've been sick of people saying that electric motors produce full power and efficiency across the entire RPM band.
How exactly do electric motors deliver full power instantly and stays constant over the rev range, whereas combustion engines gain/lose power/torque as rpms increase?
I made a video on this! :) ua-cam.com/video/VwFEyL_JJAQ/v-deo.html
Engineering Explained i thought you did, ahh i will rewatch it✌🏽
The ability to combust fossil fuels is insignificant compared to the power of the Electromagnetic Force.
The force on the piston is due to an explosion, transforming chemical energy into mechanical energy, and not electromagnetic force
If the electric motor does not get full power right away, but gradually accelerated . is it still full torque from the very beginning or do you have to floor it for full torque? I have a rc car with a electronic speed controller and when i barely press the radio it barely has any force...couldn't that be applied to electric cars so they can use transmissions?
Good video, one suggestion for you is to explore how could more gears coupled with smaller electric motor could help to mitigate the range issue on electric cars.
good explanation, how this works with electric cars.
Most people think that electric cars have gears. People calling the drive mode switcher a gear shifter, but it's not, because there are no gears.
Also somebody told me already, that she don't like that low noise electric car, because she will not know, when to change the gear ;-)
It's also worth noting that the effective "gears" are created by changing the winding geometry of the eMachine, where you trade off maximum torque vs rotational speed for any given power value. A higher number of turns means more torque (more ampturns) but also means lower maximum speed because the KE of the motor is similarly increased. However, as it's the inductance of an eMachine that fundamentally limits it's ultimate power capability (for any given supply voltage), and inductance increases as the square of the turn counts, you'll find the trend for maximum power eMachines to be towards, smaller, higher speed, lower torque architectures, and these could/will need gears in order to meet the low speed (and zero speed) tractive effort requirements
If lower KE motors have more turns then why are they relatively cheaper?does the wire gauge decrease?
finally someone civilized who uses km/h
Diego Amado XD ikr
We use mph in England 😜
Oh right, I forgot you still use imperial for distances and speeds (and a few other things I think?). The majority of the world does use metric though.
The proper SI unit for speed is m/s, but you can then convert either to km/h or mph for the layman.
SteelSkin667 well that’s made of two si units second and metre it’s not a si unit it’s self
What if it was applied in a heavy duty towing application? Wouldn’t multiple gears be feasible for torque multiplication at lowers speeds, also would a higher gearing yield more range out of the battery? Stressing it less at higher speeds should lower power consumption right?
I don't think it's necessary for towing, but i also think that a second gear with a decent gap, could drastically enhance the range of EVs at highway speeds.
no gearbox AND clutch. I reckon anyone who works on their own cars would love the simplicity of electric drivetrains
o0bananaman0o haha, yes except for the electric part.
usually people who love working on their own car loves when it has more stuff to fix.... just look at Land Rover owners...
Anyone who owns a TESLA will love that you do not have to take your car to the shop and leave it for a few days for any minor repair. Tesla Rangers will come to your home or business and do the repair where the car sits. They can repair 90% of any issue without needing to go to the shop. If you do need the car to go to the shop, TESLA puts you in the newest/best car they have on the market, as a loaner while they fix your car. Elon wants the loaner to be better than the car they are fixing.
Some EVs (like the BMW i3) go have simple clutches to disengage the motor from the drivetrain when a sudden shock is detected to prevent damage. So whenever I go over the crest of a hill at high speed in the i3 and get some air the computer engages a clutch and the motor is isolated from axle. If you are not prepared for it it can be a bit shocking because you obviously lose regen braking at the same time since the motor isn't connected. So after it contacts the ground again the car freewheels like it's in neutral for about a second and then the computer reconnects the motor.
There was an issue also when the rear wheels of the i3 were off the ground... and accelerator depressed fully the wheels would speed up to very high rpm in that fraction of a second with the lack of resistance and when the wheels hit the ground suddenly slow... A few of my fellow "enthusiastic" i3 drivers had the motor mounting bolts loosen due to the repeated shocks and that had to be fixed in a recall by getting the clutch to disengage earlier.
How much does a repair cost thought? Or are they kind of doing it complementary for being a part of the new generation so to speak.
That was great. Another great way to show this is: drawing a graph that show on a combustion engine at what speed is the car going at each gear on top efficiency and another on the electric motor
Someone had asked me about this and as I started my research your notification popped up. Interesting... I just simply forwarded your video. As usual... awesome job!
Thanks, and thanks for sharing!
I think you could have pointed out better one aspect that is in my opinion the key difference for gearing between electrical and combustion engines. A combustion engine might at best have a wide flat range of torque so you have at best more or less linear increasing power. An electrical engine on the other hand has almost constant power curve over the whole range and a corresponding degressive torque curve which is theoretically infinite at the start. The torque is more or less proportional to the current which needs to be limited and is limiting the torque therefore. Mostly only for that reason the full power is not there instantly and once the torque is not limited anymore the power curve is becoming flat even without a power limitation. And the maximum current is more or less proportional to the engine size and therefore weight. So having torque at low rpm is essentially a trade-off between engine weight and transmission weight (usually favoring a slightly bigger engine and passing on the multiple gear transmission). I am sure that is what you meant, but I think it might not have become clear to everyone watching the video.
I am a car guy and love traditional combustion engines, but electric-powered cars are outperforming them- just as cars were outperforming horse-powered transportation at a distant place in time.
The future is efficient and torque'y, but completely mute.
For racing, Hybrids is the way to go. Getting the best of both worlds!
Even as an engineer I have to say, I watch racing mainly because of the racing. The engineering is also nice, but the fun part is racing. And my answer was like that, because he said, that electric cars are outperforming petrol cars and my opinion on that is, that this will never happen in racing. Maybe on the streets but an electric car will never beat a f1 car over a normal race distance!
Yes thats true ofc. But with batteries I dont see it happening.
I am talking about racing? FE is not even remotely close to F1.
KOrbiid By design. FE is designed to be slower than F1. You can't just kill your main product. What they should do is allow electric cars in F1.
Thanks for the metric units.
During my last days on active duty in the Army, I had the opportunity to learn to drive a diesel-electric locomotive. While it isn't gearing in the traditional sense, I learned that the locomotive starts out with the motor windings configured in parallel. The gives increased torque. When the train reaches roughly 30 mph, the engineer eases off the throttle, and the windings switch to series configuration, which provides less torque but greater speed. I don't know whether or not the Tesla truck uses this same principle, but I would expect that this would be a great advantage to help get the rig moving with a heavy load. It would also be advantageous for off-road vehicles that often need high toque at low speed. It would be similar to a two-speed transfer case.
Interesting thank you
I'm very curious on the use of gears for efficiency, can you get more range from a lower revving motor? Or is power usage not proportional to the rpm?
great question
Is more work being done at higher rpm? Where? How much?
No, the same load is being driven by the same motor. The only difference is an increase in amperage for more torque and a decreased voltage for less speed. However it may be easier if I say the wattage, the total measure of electric power, remains the same.
ll.., l.
@@whatitis5646 Amp hour does determine power usage o a lower rpm does conserve battery usage.
You could also think of the electric motor itself as the transmission, as is the case on many locomotives. On diesel locomotives, for instance, the traction motors generate very high torque when accelerating from a low RPM, and generate proportionally less torque at higher RPMs, thus outputting the same power at a wide range of RPMs. This effect is called motor stalling, and it essentially causes the motor itself to act like a continuously variable transmission. Hence the motor acts like a low gear when accelerating from low speed, and acts like a high gear as it reaches the desired speed. The reverse of this effect allows the motor to act as it's own brake, which is called dynamic braking, or regenerative braking when it's used to recharge the battery during deceleration. This is why diesel and electric locomotives are able to generate the huge amounts of torque required to start massive freight trains, whereas steam engines have difficulty pulling large trains at low speed.
+Engineering Explained
So we know now why most electric cars don't need gears in normal applications, however would multiple gears improve higher speed applications? Even if it were a 2-speed or CVT.
Most EV owners are well aware of the heightened power consumption when sustaining high speeds. In your usual Leaf or Renault Zoe, the motor is spinning at 7500 or 8000 rpms. Cars such as those also start to experience a loss of available torque at speeds of +50 mph which makes overtaking awkward.
Aside from the well known case of early Tesla Roadsters destroying their 2-speeds, should every OEM EV be limited to be a 1-speed.
That's the questions we need to ask
anytime you convert power through differential gearing, theres a power loss. Combined with the added weight that a transmission adds and you lose any efficiency you would have gained.
" Cars such as those also start to experience a loss of available torque at speeds of +50 mph which makes overtaking awkward." It is not about the loss of torque but a loss of available power.
Tesla Model S and X can achieve 155 mph... how much faster would you like to go in an off the shelf vehicle? For racing applications it is totally different.
Speed isn't the factor... only torque. Electric motors have instant torque and depending on the size of the motor and gear ratio determines torque.
Lucas DiGrassi is growing on me. He takes the time for interviews, he's passionate and has big goals in mind. A worthy world champion.
Does electric motors electric efficiency decline with speed? I mean, does it consume more electricity to drive the same electric motor at 20k and at 10k RPM if both are are the same RPM (like 170 kW in Formula E)?
I had the opportunity to work with a 11 kW motor (says the manufacturer) and I had it working at up to 48 kW but just after the peak power it just started dropping (a lot) but I still had the engine sucking up 48 kW electrical energy.
I'm just wondering if that was just the controller that wasn't properly set up, if there was too much friction losses or if the electric motor itself becomes less efficient.... Could that be a reason to have multiple gears so you avoid running in that high rpm low efficiency state?
Sounds like you over-saturated the coils. You hit a point where throwing more electricity at a motor just produces heat, not power. You should be careful, heat can destroy a electric motor fast. Excess heat will demagnetize the rare earth magnets in the motor.
You can also use different windings on an electric motor as gearing... resistance is the reason for gearing to begin with so it should not be a surprise that windings are used as gears for efficiencies of fuel/energy
If you use two windings, of different lengths, you really have three "gears" 1=short winding, 2=long winding, 3=both windings in series, with two SPDT switches (and something to prevent both switches being set to the same tap point, which would short out the circuit.
So overall, would there be any benefits to have a CVT in an electric car? I ask because if you're going to have any gears at all, why not have it be the most efficient type?
Chaotic-Good Antinormie CVT has big losses and whole point of cvt is to keep the engine at constant power/engine speed at peak efficiecy to neglect own loses. Electric motor by design make constant power over most of their rew range. Simplest reduction gear is most efficient way to trade frequency for torque.
A transmission has a efficiency of around 85-95%, depending on the rev. So in you can save 30% power during acceleration for about 30 seconds, but loose 5-15% during crusing for the next 10 min you are way worse off with a transmission
Ooh, Formula E! I've recently become a big fan of them.
I like that they post all of their races here on UA-cam.
I think with a gearbox an electric car could use much less power to keep the car in speed at -for example- 120km/h, thus the range of the car would multiply.
not really, as you only use power to get the engine to certain rpm (a lot of work), then to keep it at that rpm (not too much work), this is why cars are economic when they keep the speed but consume much more fuel when accelerating. Most of energy is used to spin the wheels, not the motor and to lauch a car in specified direction, not to spin the engine itself, so it won't have any great impact on range.
I agree. Most modern electric motors run on 3 phase alternating current with a frequentcy converter, and i was thaught that when the frequenty increases (aka let the motor spin faster) the inpendance also increases therefore losing efficiency.
So if there is a gearbox the engine can rev lower and have less internal resistance.
@@Sjef0194517 But if the internal Resistance is higher less Power is transferred, because less current is Running in the Motor.
The main reason to have a gearbox on a electric motor is to accelerate faster and to climb hills easier. When a electric motor gets bogged down (like on a steep uphill climb) it can heat up very fast and destroy itself. Not to mention it's much less efficient running at low rpm with high load. Better to use a gear ratio to turn it into high rpm and low load.
Porsche seems to agree with you
Nice final frames with the rain :) I have an 2016 Tesla P90D and it surely feels like it can have a second gear engaging from 70mph on. While the car has an enormous amount of power in the low speeds, it loses that power advantage to gas cars after 70mph. And yes, I do acknowledge that this means more complexity and more strain on the battery. But just imagine the crazy acceleration up to 150mph :)
That is what I am saying as well. I don’t own an electric vehicle but take that Formula-E car for example. It does 225 kph with the electric motor and just 1 gear. If you were to just slap on ONE more gear then you could easily get 375kph or maybe 400 kph out of the car. I understand that the electric motor is high revving and all but you can’t tell me that, speed-wise, it wouldn’t benefit from just 1 more gear!!! Crotch rockets oftentimes redline at or around 15,000 rpm and they have more than 1 gear. I know it’s apples and oranges but still. I would like to know your thoughts on my opinion, if you don’t mind.
You went from a white board drawing images to a very good art.
Always with very good explanation.
Can you do a video which explores homemade diesel fuel? How is it made?... Does it have any negative affects on modern diesel cars like a Mercedes BlueTec?
Thank you so much, love your videos and all the work you put into making them!
I’ve seen two fuel cars that start on regular diesel and once warmed up switch to used filtered cooking oils. Interesting. The exhaust makes me hungry for fish and chips. Seems to work alright. It may not work really well when it gets cold outside as the bio diesel may gel up. I saw that happen to a huge barrel of diesel used to run a diesel electric power system. It was fall and winter grade diesel was supposed to be delivered and accidentally got summer diesel. After a short tome the lights went out. It’s really hard to heat and drain a 5,000 gallon diesel tank. Tough lesson learned.
I have a question. How much electricity is actually being consumed at the various speeds of the motor? Say, 5000, 10,000, and 20,000? I would think highway driving, even with an electric motor, that keeping the RPMs low would be just as fuel conservative as it would be for a gas engine. And I would think if an electric motor is good for torque and very low RPMs, why not gear it to run at low RPMs with a kinetic reservoir like a flywheel. Then there's the argument of which is better, volts or amps.
Well, you've certainly got the ideas down! The biggest problem is cost, and complexity, not the theory behind it.
It's a given that a motor performing more work will consume more power, gasoline or not. An electric motor has more spots where it can remain efficient compared to a petrol motor, but of course running it at maximum power will use the maximum power it is capable of using. Kind of how maximum brightness on a phone eats up a bit more than turning it down. Not by too much, but still a percentage.
Of course, ultimately in these independent lab scenarios, weight and complexity bring up more and more questions about how we could go about new technologies to further improve the electric motors. I say we are still in the infancy of what kinds of new technology/innovations are available to us, but perhaps we'll have another "Roaring 20s" of our own after coronavirus!!
Electric motors do not really use more energy in high rpm. The power consumption is because of the load on the motor, not the speed of the motor. If you step down the rpm via gears, the load or force on the motor increases, increasing the power consumption greatly. Since it is efficient in all rpm, this would have no benefits. Electric motors can stick,slip and melt at low rpm, so it may even be less efficient or dangerous.
@@zazethe6553 Electric motors are more efficient at higher RPMs in some tables.
Hey jason! I tried to make a suggestion on your website, but was unable to due to a glitch in the system. I just wanted to recommend a video in which you explain the benefits and shortcomings of polyurethane bushings, spherical bushings, and standard rubber/OEM bushings in a suspension. I once had a very experienced automotive engineer tell me that he prefers rubber bushings and that it's a common misconception that poly bushings are superior, but his explanation was too complex for me to comprehend... I understood that the principle was that poly bushings limit movement in the suspension components, leading to less responsive handling, inaccurate alignment, and reduced mechanical grip. I was hoping you would be able to explain this more in depth and in a manner that a fresh ME student would be able to grasp, and I'm sure many others would appreciate the insight. Thank you!
Very clear and precise explanation.. tq bro.
Happy to hear it, thanks for watching!
And another thing from my observation is that the gear ratio can be chosen to go close to the maximum acceleration possible the limiting factor being grip. For example I’ve calculated for bmw i3 a 0.54g acceleration from the motor and I figured this roughly matches the grip of the tires given that they are not super sticky and the weight distribution is 50/50, rwd because the friction coefficient is around 1 and 50% weight on the axle means a value around 0.5. This confirmed when you drive the i3, you feel the tires are slightly below the traction limit because they squeak a bit.
With a normal (ice) car they would make a short ratio and give you more wheel torque than needed to make up for the clutch slip, to have extra traction when fully loaded, and to make them drift, but sometimes it becomes difficult to control and you loose traction (see m3 vs i3).
But tesla with awd goes with faster acceleration but the power is much higher also.
That was so cool, thanks man I learned much!
I could see a use for a low crawl ratio for 4x4 vehicles. I single planetary could be attached at the front of the motor(s). It would be locked up for road use, but when climbing steep hills or rocks, you could unlock it for an extra 4:1 or so. If the conditions of the shift are controlled, you could do it to multiple gearboxes at the same time if you had independent axle or wheel motors. You could also use it to boost motor speed during regenerative braking to put more power back in the battery.
Thank you for using metric units.
Assuming the widths (which affects grip way more than circumference as far as I'm aware) of the wheels stays the same (let's say 8.5") how much quicker would going from a wheel diameter of 18" down to 17" or 16" make your vehicle accelerate? The smaller wheels (in theory) should act the same as having a higher final drive which will effectively increase acceleration and decrease top speed in each gear (and top speed in general).
More formula E videos please!!!!
Instead of explaining why electric motors have no gears, explaining why ICEs have gears would be way better, because former is more intuitive anyways :) But I'm sure you explained the latter already so it's still nice to have videos about electric vehicles. I love to see rising popularity of these vehicles as a power engineer.
Rimac uses 2 gears and the concept one is one of the quickest and fastest production cars in the world
matthew clark the concept one is not a true production car....doesn't meet the sales volume to be classified as one.
Yes so technically the fastest production car today would be the Tesla model s
Christian Thompson not true...what's its top speed vs Porsche
But Tesla P100D is quicker than Rimac 1 from 0-60 mph because of one gear.
Tesla is fastest accelerating production car in market. It doesn't have highest top speed though due to software limited top speed. Mostly because batteries overheating so Tesla has to reduce speed down. Roadster might be able to go on high speeds if Tesla will fix overheating issue
Great explanation! I am a fan from Brazil and it is very satisfying to watch this video. I am also a eletronics engineer student and I am currently working with a project for university about eletric car and I had this very question about gears in eletric cars. Thanks!
why don't they make street e cars with gears to maximise the distance a car can cover with one battery charge
Electric cars you can buy normally use a CVT.
So the power usage is lowest whilst still providing enough power.
Again, it's not necessarily worth the efficiency losses that go into adding a geared transmission. Also adds weight and complexity. Electric motors are efficient across a wide range of RPM, so adding gears could potentially mean reducing efficiency.
IIGrayfoxII What EV has a CVT?
With a synchronous motor the efficency doesn't change as much with rpm as a combustion engine does. So the efficency gain with more gears is not as big as the gain on combustion engines. But it makes the car heavier, which decreases the efficency, which smallers the gain even more. And of course it costs more, and the price is beside the range one of the biggest problems for electric cars at the moment.
you mean like tesla?
Great video. I’d like to suggest doing a video on tires and proper rotation and tread wear guidelines. For example, I’m having a disagreement with coworkers on replacing 2 or 4 tires at a time on their front wheel drive vehicle. I maintain that if you are only replacing 2 tires you need to make sure those new tires go to the rear of a front wheel drive car to prevent over steering. They think new tires or best tread tires should be in the front because it’s the drive tires on front wheel drive. I try to explain that regardless of front wheel, rear wheel, or all wheel if you have miss matched tread depth tires the best 2 should be on the rear to prevent oversteer where the rear end lets loose which is harder to control than under steer. Anyone with an opinion please chime in? Thanks!
4:04 who saw that guy get rear ended?
I know this is an old video, so you may not see this comment. But the question I have always had about gearing and electric vehicles pertains to efficiency, in terms of what we call gas mileage in an ICE car. I understand that low gears are not necessary for electric vehicles to get adequately started moving, but couldn't there be some efficiency gained in terms of 'mileage' or range by giving them overdrive gears? If you had some very aggressive overdrive gears could you not save energy and increase the range of the vehicle by allowing the electric motor to hum along slowly while keeping the vehicle steadily cruising at 60-80 MPH?
Why do electric cars need brakes at all? Motors are capable of applying torque equally forward and backwards so surely they can slow down as fast as the tires can grip.
For emergency situations. And depending on the state of battery charge (completely full or completely discharged), the regenerative braking might not work at all.
Expect to see a brake-less electric car soon.
Surely it is wrong. Decelerating at grip level from high speeds needs much more power dissipating(recuperating) than regular electric motor can provide.
Great video, your work on these keeps getting better and better.
You sir, have a subscriber.
Love it, thanks for subscribing!
0:56. Everything I needed to know said in about 10 seconds. An electric motor has a single gear calculated for its top speed but has the same torque from 0rpm up to its max so it’s useful at all the lower speeds.
Rimac has 2 gears
Exactly
Tiago Ferreira Doesn't mean they are right. They could have just used a larger motor with the same weight as the gear box.
difflocktwo they aren't right. But they have the fastest car in the world.... why?
Yes because they want an extremely high top speed.
You don't even need to post this.
Battery lifespan is a major concern, but I wonder what the lifespan of the electric motors will be with them possibly spinning at very high rpm a lot? What about the magnets in the electric motors, will they degrade over time? Time will tell.
Electric motors last, generally, far longer than ICE for a simple reason. The only part that wears out is the bearing that allows the rotor to stay in place. Depending on the quality, it can easily last over 1 million km. What will wear out way before that will be the transmission.
I think once they can figure out a battery tech that can survive far more charge/discharge cycles and maintain a good power density than current lithium/lead acid batteries we will see a HUGE EV explosion.
But until then dinosaur powered cars will stay the king.
Magnets do wear out with extreme heat, nothing that liquid cooling cant solve...but only dc motors use them , ac motors dont need magnets, they are basically opposed pulsing electromagnets..
Jordan Anderson Check out Jay Leno's Baker electric on UA-cam. 100 years old, still works perfectly. Batteries are new of course. but the motor will last generations. Our whole industry runs off electric generators and motors. They will last a looong time even at continuous duty. You can design any part to last as long as you want, but there are compromises.
Modern batteries will probably last a million miles in a car. The batteries will out last the car and owner.
These motors are AC induction, so no magnets or contact points.
It'll be interesting to see if multi-gear transmissions ever catch on in production EVs. From what I understand, it's really just the cost of materials holding them back from being a reality (need VERY sturdy components to handle all that torque) - but in a road car, the benefits are also minimal. The original Tesla Roadster was supposed to have a 2-speed automatic, but they could never keep it in one piece... ultimately, it didn't matter.
Not having any gear changes is also one of the things that makes the experience of driving an EV unique. A lot of the early automatic transmissions in the 1940s had the same selling point - no gear changes whatsoever on an original Buick Dynaflow. Back then, there were some people who thought the Torque Converter alone would be sufficient as a manual transmission replacement... turns out people weren't willing to part with all that efficiency and performance. But those early automatic Buicks are definitely a much, much different experience to drive than pretty much all of their contemporaries.
Love EE, love Formula E - keep up the great work homie.
But wouldn't having multiple gears allow it to use the electricity more efficently? I mean, that's why we have them in bicycles.
Well a human has a very narrow power band compared to an electric motor, so we really need a few gears on our bikes to make them more practical. There are a few bikes that doesn't have multiple gears, one of them being the "fixie" and I think there are some velodrome race bikes that has a fixed gear ratio. The fixie isn't really a practical bike, and the velodrome racers can't start without having someone help giving them a push. Other than those it's mostly children's bikes (and possibly BMX?) that comes with a single fixed gear.
Blahorga Slisk....If I can I buy today car for my daughter with fix gear sow she can start slowly and have speed limits...every beginners should have car with fixed gear or looked automatic with two gears :D
lolinskimk6 ...gear boxes go to hell in short time with instant 20 000 rpm
He said in video, that adding gearbox is too little advantage comparing to added complexity and weight (which reduces range). It is just not worth it.
If you watch the video, you will learn.
Fun fact: dual-motor Teslas (75D, 100D, P100D) have different gear ratios on each axle (but a single ratio per axle). The rear ratio is optimized for acceleration since the weight shifts back there during a launch, while front ratio is optimized for highway speed cruising and better regenerative braking, since the weight shifts forward during braking. So launching at a traffic light, you're in a rear-wheel-drive muscle car, but once you're past the on ramp you're in a front-wheel-drive economy car. On a highway, the rear axle is essentially in neutral until you're ready to pass that slowpoke Dodge Challenger. Best of both worlds, which is why the dual-motor configurations actually get better range than the older RWD only models.
I'd love to have a stick in eCars....
pSyk there was a Chevy S-10 I seen once that was converted to EV, but it also retained the 3 pedals and 5 speed. Wonder what that would be like to drive, I'd bet if you actually shifted it'd be very fast, as you can even get decent acceleration just in 5th gear alone lol
Look up the Detroit Electric SP:01
Some of the FE cars have a gearbox for better torque management...but it's flappy-paddle operated (stick would take up too much room in those cockpits).
pSyk why with it you lose space money and you slow the car down
In trade for range and entertaining driving. Quite a treat!
You ask a question, but answer another one.
As you explain things really effectively and comprehensively I still feel unsatisfied, because I'm really eager to learn why electric cars on the market have no 2nd or 3rd gear to allow them reach higher, than 160km/h, speeds. I only know that Tesla, when developing the first Roadster, had massive problems developing the gearbox hence they eventually gave up altogether and released a car with just 1 forward gear.
I hoped you'd actually tell more about these difficulties - why is it more challenging to create a gearbox for electric cars (Tesla tried with vendors for 5 years before they concluded they failed).
this is dope
Jason, have you ever considered automotive engineering since you majored in mechanical engineering? I saw the video on why production cars haven't reached 300 mph and I wondered if you ever considered working in that type of field to help improve the automotive industry or help break records such as the 300 mph milestone.
Any car going above 350 km/h will go through a full tank of fuel in around 7 minutes. I'm not even low balling the number, that's how much energy is required to sustain the speed due to air friction. It's not practical because it wastes too much energy to travel just a short distance. At low speed the energy per km drops.
christian linero where would you be driving your 300 mph car?
I still love the sound of a V8.
It is great and everything but it's time to move on now.
Me too, but do our neighbors? Or do you like it when you're sleeping or working? I don't.
David McClelland
Until EV's can go at least 400 miles on a full charge and charge as fast as filling up at a gas station, i'll pass.
al kiou
One of my neighbors has a loud motorbike, and no one seems to be complaining about it, even in the morning and night.
+Ghost Toast obviously you are not old enough to recall winter's of decades past. Winter now is more like a cold fall
electric vehicles use electric motors with iron core on the stator. why not use ferite core instead of iron. ferite core transformers for example are much cheaper, more efficient and many times lighter than iron core ones. the only difference is the magnetic flux those core types can take before saturation and the frequency you can use them. ferite cores saturate at lower magnetic flux, but can take much higher frequency signal before having hysteresis loss. engineers might say the problem is the motor would reach much higher rpm and would have much less torque, but if you make it have 10 phases instead of 3 and have 100 sectors instead 9 it would have the same torque, but higher max rpm and higher efficiency
incoming electric car haters
JohnnyDebt yes, there will be...but they dont hate them, i for one dont...but to ban vehicles with internal combustion engines, thats what triggers!!!
Don't forget the human drivers :) they're worse for the environment than the petroleum.
JohnnyDebt
I don’t hate EVS
I just believe consumers have a right to choose between combustion and electric
Not everyone wants an electric car
Golden Retriever yes, agree with you on that 100%
Golden Retriever At some point you will have to. Oil is a finite resource.
But toque... you can put a lot more torque into tarmac higher gear ratios. The "acceleration" will be much higher, if a higher gear reduction is used at the beginning. And then switched to "cruise mode" to keep it going. Can come handy in electric jeeps - for pulling heavy loads. Can come in handy it traffic jams for... no, in traffic jams high torque causes jerky movements which merely increase the risk of accident, lol.
Question: "Why do electric cars only have 1 gear" Answer = "COST"
Question: why is electric cars soo expensive if they're built with low cost??
Because they aren't (yet) built in high enough volumes! But that's changing and changing fast. the next ModelYear platforms are likely to achieve cost parity with ICE, and the one after that will be cheaper!
Because batteries are crazy expensive...
@Max Torque the Nissan Leaf and Tesla Model S is both mass produced...
@Rondo Cat if that be the case battery EVs will never take off... as they'll never be able to build an affordable EV...
If you have a motor and controller that controlls the stator field current then you can have a single tall gear ratio and manipulate the field current to get more torque at lower speeds, and have a high speed range at constant full power output. This is typical for a DC motor with brushes and a separately excited field (not using a permanent magnet stator field). For full acceleration the motor can output maximum torque at lower speeds with the stator field at full current. When the speed has reached the rated speed for full power the system goes into the constant power region of operation. As the speed continues to increase, the field current starts to be lowered while the armature voltage stays at it's maximum. While the speed increases the torque output decreases (as the field current is lowered), but the power output can remain constant at full power as the system accelerates up to the maximum motor speed (or some other design limitation). In the constant power region it has a similar effect as having a CVT transmission.
Engineering fail. HP = RPM X torque. An electric engine at 10,000 RPM produces ten times the power that its does at 1000 RPM. Obviously, you need a gear of some type would be highly advantage. In reality, most electric motor's use a drive scheme that drives the poles in a way that gives the effect of a mechanical transmission, but in an electric way. This is done by selecting the way the poles of the motor are being driven. Many poles = lower speed = more torque. Fewer poles = higher speed = less torque. No transmission required, because it can be done electronically.
Look at it like this. If a electric car has 600 HP at 10,000 rpm and 100 MPH, then it only has 30 HP at 500 RPM and 5 MPH, when it is getting started. But we all know electric cars are quick off the line.
tkorocky Nah, if you want HORSEpower ya gotta also divide by 5252.
While you are correct in an EV there are a few other factors. The battery for example will have a maximum current discharge limit. Power = Voltage x Current.
One question, how electric car move from 0 speed if it don't have power? I think this way of thinking is good for gas car, but not work for electric cars.
Sędziwój Poljak:)
Power is product of speed and force. 0 rpm zero motor makes 0 power, but it has max torque or force. It acelerates with constant torque until it reaches max power. When it reaches max power, torque start to drop, but product of torque and revs stays constant, so it makes constant power. It max rews are limited by internal structure and by overrewing motor would fell apart.
Fun fact: the BMW i8, which was shown in the video and is Formula E's Safety Car also uses 2 gears on it's electric motors. But it's a hybrid, not a pure EV. Its ICE has a usual 6-speed transmission...
They only have 1 gear "fast"
We make small compact brushed dc electric motors with high torque and low rpm (2400 rpm) Gives about 11 hp more than enough for a go cart.
I know you guys avoid customary units like the plague and metric units make more sense, but for the ones who still use the customary system in daily life, it would be nice to give the conversion in parenthesis next to the metric unit. It doesn't even have to be verbally said. Just written, so us customary folk can conceptually understand on a more relatable basis. Thanks.
acelakid94 Welcome from the club of metric units. Nice to see you finally understand our common predicament when we watch American videos.
Alex O. Haha but he's right they should have...
Remember last time someone added metric units to help you and you didn't have to Google the data. How you thanked them.
It's the little things in life you know.
I think you don't really need the imperial units to understand why a electric car doesn't need more than one gear. I guess it would be nice for you to immediately know if a formel e car is fast or not or how lare the tires are, but the math behind it keeps the same. And if the cars topspeed is 100 or 140 miles/h is, as my professor would say, trivial.
XilefR Sure, I don't _need_ it. The concept is simple enough to understand regardless of the units used, but it's nice to see a familiar number next to the foreign one. Besides, he says, "...what if you want to go 20 km/h?". People who use km/h know that's like a brief human sprint speed while I'm here doing the conversion to also have a similar real world comparison in my head while the main idea is further explained.
In the end its all about relativity and as a imperial unit user, *I literally cannot relate.* 😂
No, convert and adapt, the imperial system needs to be abandoned because its inferior.
2:55 hehe my 4.7L V8 4Runner idles at 500 rpm and will chug along at about 800 on a flat surface in 4th or 5th gear
First
The ideal setup for a performance vehicle (and trucks) is exactly how rimac does it. Single speed in the front and dual speed in the back. This video also didn't show that electric motors torque and consequently power drops off tremendously at high rpm so a second gear helps for not only top speed but also acceleration after 90-100mph.
For commuter cars, no, single speed is by far the best.
I like these types of videos with the vids in the background better than the one with the whiteboard
In a road car, an electric motor could greatly benefit from an overdrive gear for use at highway speed, right? Something to drop the revs down to something like 1500 or 1000 rpm at 70 mph. This would greatly improve mileage on long road trips.
I agree
Do any of the teams use electric gearing (as in variable frequency AC drives?)
That way you can match your torque/RPM ranges without any mechanical gearing
You should do a segment about pros and cons of induction vs permanent magent electric motors for cars
Thanks very much. In the example you cited where the motor will be doing 20000 rpm at 225 kmph, if we use a taller gear to do same 225kmph at, say 10000 rpm, we can increase the range. Isn't it?
Nice video and graphics. It'll been cool if you added MPH as well.
Great video, but it just make me more curious. With the advantages and simplicity of an EV drivetrains (like what's used in the Nissan Note E-power),.Why don't all vehicles use them? No matter where the electric comes from like a battery, or an ICE used w/generator (or 100s of other options that become available)? And why do most BEVs, use motors with just poor performance (just to keep the driver from using to much energy)? And I guess I'm later to the party since I just saw ur Series Hybrid Cars - Explained post.
A multi-speed transmission can allow for a smaller motor and a less powerful battery pack for the same multiplied torque to the road through the tires. The losses through the extra gears is negligible in comparison to a bigger ampere draw from the battery from a 1-speed transmission. There are well-published charts from battery cell manufacturers that show the discharge rate at different "C" ratings. There is also a trade off in batteries between building a cell for maximum watts hours per kilogram versus building a cell for maximum watts per kilogram. In Formula E the race is always a balance between speed and range. Mark Yormark
my first time to view your video without the whiteboard marker.
keep improving man
Excellent presentation, and thank you for providing metric units.
Would the 3 speed not also have an advantage in saving battery power, needing less torque saving battery power, as it is ultimately an energy saving contest still.
I have had this question for a very long time: how are 2 different power sources (an ICE and an electric motor, for instance, not necessarily spinning at the same speeds) connected together so that they can combine their outputs to drive the wheels? I've wanted to know about this since F1 introduced KERS and supercars increasingly turn to hybrid technology to overcome turbo lag. I've read that the MGU-K is connected to the engine's crankshaft but that's all I managed to find out.
Enlighten me, please?
Have been wondering about this for a while. Thanks for the nice explanation!
Kind of a simple answer. The motor or motors drive the wheels directly. And BTW, I seen you on the newest GMC Canyon commercial.
My Puch Maxi S Moped which originally has 50cc’s, has a 70cc Zylinder and bigger intake and outtake. And it revs all the way up to 11’000 rpm and runs about 55-60Km/h
could you make a video about the types of brake fluids and their pros and cons , and in what type of vehicles they're used.
When I was a kid I had a remote controlled car with 6 gears. If you put it in the gear with highest top speed it would be really slow to accelerate and you would use up the battery in 10 min no matter how fast or slow you did go. Put it in low gear and you could drive for a hour. If you did go for the middle ground that gave ok acceleration and ok top spead you could drive for about 30 min and again speed did have little influence on how long time you could drive. As far as I know this still stands for electric engines of today at least to some degree (less then before because of higher max rpm), having gears will actually help on the economy as well as acceleration. Problem is to maker a gearbox that can handle the torque...
You know what ? You can do gearing inside motor winding as well, make two of them and in low speed make it in series, at high speeds make in in parallel do to back EMF. And surprise, you have gearing effect at some cost from electronics :)
It will feel like VTEC :D:D one very well defined spot, just inverted :)
I'm curious how this will work with a semi truck. With all the added weight, wouldn't it be necessary to have additional gears? I drive semis, hence my curiosity.
This was a great explanation! Have you done a video explaining basic ev drivetrain?
Yes, check out this playlist for more! :) ua-cam.com/play/PL2ir4svMoaYj48N0VWoic25P9LaU2wlbA.html
gearing can definitely add performance to an electric car. there is a limit to how high you can rev. its more efficient to be at say 5000 rpm at 200kmh than being at 15000 rpm at the same speed. excess rpm is both bad for wear and tear and also it means extra loss of energy. If FE was held on F1 tracks like monza, 3 gear could help with top speed better than accelerating.
Depends on the rules and if the 170kW is electrical pack discharge / measured at the controller, the motor, or the wheels. If it's measured at the wheels then you would be crazy not to have a gearbox. If it's limited at the controller, be a tough call, and may be circuit dependant.
3 gears makes sense. Remember from stand still, you huge power from the battery to get going. Torque is not free energy. Gears can reduce stress on the battery and increase the range.
Prius use tiny electric motors with cvt gearbox for more efficiency.
some main issues for road EVs with single gear:
1. relatively low top speed (most EVs have top speed of less than 100mph)
2. much slower acceleration from medium to high speed (50mph to 80mph)
2. significantly more energy consumption at motorway speed (a Tesla at 80mph uses significantly more battery than at 70mph)
these are putting me off EVs (assuming charging won't be much of a problem in 2-3 years' time with 300kw DC fast charge and 100kwh+ batteries on most affordable EVs)
but if the power isn't limited like it is in FE, then more gears will allow you to have even better acceleration as well as higher top speeds.