Great video and very interesting......but the historical follow-up 4.5 years later is a bit painful to read: "The Nissan GT-R LM Nismo...the car made its racing debut at the 2015 24 Hours of Le Mans. Three cars were entered for the race by Nissan Motorsports, numbered 21, 22 and 23. The cars qualified in the last three places of the LMP1 class with times over 20 seconds slower than the pole position time set by the #18 Porsche 919 Hybrid. The #21 car was actually out-qualified by the fastest LMP2 car. After the three cars failed to achieve a time within 110% of the pole position time, they were demoted to the back of the prototype grid.[29] The #21 car retired from the race after 115 laps with a suspension failure, while the #23 car retired on lap 234 with gearbox issues. The #22 car finished the race, but was not classified as it failed to complete 70% of the race winning car's race distance. The car was never raced again."
On your explanation of the aerodynamic advantages: The other LMP1 cars are mid engined so the rake of the rear diffusor can still start relatively early. But the the mid engined cars also have a front diffusor which i imagine is harder to implement with Nissans front engine.
Or, you can make an effort to think, watch a couple of videos on simple calculus and what it means to have a function... and expand the limits of your thinking. Does it not sound like something worth doing? Or does self-pitty seem like a better way of presenting yourself to the world.
your force direction convention is opposite your acceleration direction convention lol. typical vehicle dynamics and free body diagrams would show the forces on the depicted system, so the forces would be reverse of your convention, but your explanations are great
Haha yeah, sometimes you get caught up in the heat of explaining and draw arrows the wrong way and hope people don't notice... It made sense to my mind in the 30 seconds at the time as it couldn't decide to work on force on ground or force on tyre :) Thanks for watching!
Nice Video. Nice Explanation. I'd like to watch more of you videos but for one reason. Please improve your audio. The reverb is really annoying. Probably a Headmic would help. It would make your videos even easier to follow and to understand. Literally. Maybe some audio editing would help too. Sorry for any mistakes in my language. I'm not a natural speaker.
Thanks for your feedback Julian! You may not believe it, but I went to quite considerable lengths to try and clean up the audio on this video, including filling the room I was recording in with cushions to absorb the noise! I do agree that it is a still a problem, perhaps I will have to look at investing into a lapel mic... Thanks for watching!
SpecialKLSX I ended up buying a shotgun mic, I couldn't find anywhere nice to hang a bedsheet... Tell me if you reckon the audio sounds good on my latest video about the Regera
Fastest acceleration is rear wheel drive only. Ever. Period. Weight transfer is king for the first 60ft, and the first 60ft decides everything. Le Mans is not about acceleration. It is an endurance race. Long duration durability, fuel economy and tire life are larger concerns in a race like this than any other type of race (they're always important). The ability to dynamically adjust which wheels are using their traction the most is a HUGE benefit to tire life. Regenerative breaking to extend fuel economy is a HUGE benefit. So the question is much simpler than you represent it. The question is, "Can we build a car that is fast enough to be competitive, and still gain those other benefits of a hybrid powertrain?" At Le Mans, fastest means nothing. It's a different race with different considerations. This LMP is not designed to be the fastest. It is designed to win Le Mans.
@@ChristnThms I don't see how that makes any sense. All the fastest accelerating cars are AWD. AWD is rear wheel drive, but with extra power from the front wheels.
But you're wrong, and not doing any research. The reason is weight transfer. At the moment of acceleration, weight transfers from the front to the rear. This is why the front end rises during acceleration. When you accelerate hard enough, the front wheels will come completely off the ground, this completely negating any forward thrust they can provide. The reason that high performance production cars are often AWD is that the weight and crappy traction provided by street tires doesn't facilitate weight transfer very well. But, even in street cars, RWD is king.
This has blown my mind. I have no idea what you just said but thank you for the video. I'll try to get increase my knowledge over time. I'm an avid GT and endurance fan but have very little understanding of the lmp1 classes
In the P=F*V part, you state that the force goes down as the velocity increases. This is under the assumption of constant power delivery. So yes, to put the same amount of power down, there will be less force at high speed. However, the required power, to overcome aerodynamic drag scales with V^3. Pdrag_aero=1/2*rho*A*Cd*V^3.
Cheers for making that video, it was very informative. My thinking is that static friction and dynamic friction play by two completely rule books. As these cars are raced on the limit of static friction, tire compound and surface area therefore require a different spec sheet. Nissan are on the frontier of applied physics and this is what excites me the most. Good on them for being so bold.
thanks for very interest and informative videos..admittedly I don't always understand everything your explaining but that's me not your explanation..keep them coming ..love them all
This is actually quite genious. It puts weight on the front axle which is helpful while turning especially in slow speeds where you dont have downforce to make the front work. Also most the power is still going down on the rear than the front so its more efficient use of power. It might be a very oversteery car though when you dont have weight or downforce to put down that 700 electric horsepower.
Great video! Finally more car physics videos! I do have a question that's been bugging me awhile: if surface area doesn't matter why does wider tires give better grip when compared to narrow tires? Assuming that the weight of the tires are the same and mew is constant? Thank you
Glad you enjoyed the video! As I briefly mentioned when talking about balancing the FWD characteristics, tyre area does in fact matter, hence the need for wider tyres at the front. Increasing the contact patch and tyre size raises the amount of total energy the tyre can take without overheating, thus ensuring optimum temperature for optimum Mu. In addition to this, the tyre curves that I mentioned offhand come into play. As the normal loading increases significantly on tyres, the effective mu value will taper off, this is the same reason why weight transfer during cornering is bad and why we want a low CG. Running a wider tyre/bigger contact patch reduces this mu taper as the normal load per unit area is lowered. I can do another video on this if you would like? Cheers, Kyle
KYLE.DRIVES I understand, thank you. Another question I've been wondering has to to with car spoilers. I've seen your videos on the subject already but my question is putting a spoiler upside down? Or putting an airplane wing shape to create lift not downforce. Not for racing obviously but for regular cars doing regular driving. My thought process is if you create lift on the front and back of the car let's say driving on the freeway going 75/80 mph, can the wings take off a substantial amount of weight off the car causing an increase in gas mileage? Basically at freeway speeds turning a 4,000pound car into a 3,500 pound car. Thanks for the prompt response
Dr Noro A few things on this point, first you have to differentiate between mass and weight, reducing the force on the tyres does not make the car have less mass i.e. it will still take the same amount of force to accelerate it at a given rate. This is why racecars with considerable downforce can still accelerate so quickly. Obviously the increased rolling resistance from the higher force on the tyres will be a factor, but at highway speeds rolling resistance is a small component of overall losses. What you must remember is producing lift or downforce inherently creates drag, as the up or downwash produces vortices behind you. The most efficient configuration for drag will always be zero lift, zero downforce. Solar car teams often aim for just enough downforce to keep the thing from flying off the road in gusts, but keep this number as low as possible to reduce drag. You may want to look up Sunswift eVe, I have had many conversations with the people who designed the aerodynamics on this car, and it does make a bit of downforce, despite being a world record breaking solar car.
Dr Noro I just wanted to add that a usual roadcar already creates lift at higher speeds (certain sportscars of course don't), so you don't want to add to that, because all you want is a stable car. Audi even had to subsequently add a small wing to their first TT generation, because it was too light in the rear at speed.
In my opinion what nissan has done here is the ideal because as well as what's discribed here there's the delivery of power to consider. A petrol engine has to wind up to produce power i.e. there is a maximum amount of torque available at any given engine speed. With a motor however isn't quite the same. A motor, whilst horrendously inefficient at large slip figures, will draw as much energy as possible to reach the point at which motor slip energy draw equals energy consumption. What this means is motors are capable of much better torque curves then petrol engines. So since the rear wheels provide the best grip due to weight transfer under acceleration that's the best place to put the motors. However, the petrol engine provides more power for weight i.e a tank of fuel verse the batteries and so is perfect for doing the majority of the grunt work at higher speeds. Driving through the front wheels has all the advantages described particularly since as described the centre of pressure is being dragged by the front wheels which is more stable then pushed by the rear. Just my opinion. Great bids, really like the way this guy explains stuff.
you did a prety good job of explaining what's going on apart from the part where you are saying it also has an electric hybrid sistem.....i was reading an article about this car (it was top gear i think), where they were told that the hybrid part is not electric but an 8kg rotor located in vacum, so when you brake, the energy instead of charging batteries is used or transfered in to kinetic energy of rotation of that mass (huge rpm's, about 60000 i think), so when they need to deploy that energy it is conected mechanicly to the rear wheels via cluches and drive shafts :D so if i understanded it corectly, energy for braking is harvested and used to rotate the flywheel (accelerating 8kg to 60000 rpm needs a lot of energy), and that kinetic energy (i calculated it at about 14,2MJ if you assume it has 60cm diameter) is sent to rear wheels when needed like a quite big burst of energy :D i hope you find that interesting and understanded what was i trying to say because i am not native english speaker :D
Yeah I know, sorry, as I made this video the information out on this car was very limited, and most articles stated it was electric with only a bit of speculation about it being a flybrid. Since I uploaded the video it has been confirmed a flybrid, and that is just something I will have to deal with being wrong in the video (might put an annotation on it). Even top gears article released 1 day before I made the video listed it as electric: www.topgear.com/uk/car-news/nissan-gt-r-le-mans-car-2015-02-02 "Because while the fronts have to cope with 550bhp of internally combusted goodness, the rears have to manage somewhere in the region of 700 electrically generated horsepowers." This actually isn't the first flybrid car, I believe Porsche had a prototype flybrid GT3 back a bit. Thanks for watching!
KYLE.DRIVES Audi uses a similar flywheel system (except with less capacity) in their LMP1 car since 2012. The system was actually developed by Williams for the 2009 F1 season (when KERS was introduced to F1), however the concept was banned from F1 before they had it race ready. Williams kept developing the system and supplied these units to Porsche (for the GT3 car that almost won the N24 in 2011) and later to Audi (for the cars that won LM24 in '12, '13 and '14). So the flywheel hybrid is not new, it has been around for some time. Nissan have not yet revealed if they are also using the Williams system or one from a different supplier. Either way, it is expected to work the same way the Williams system does, and that has nothing to do with clutches or drive shafts like janezick suggested. The hybrid system works just the same as any other electric hybrid, except that the electric energy generated under braking is not stored in a battery. Instead it is transferred to a motor/generator unit that powers a flywheel. The energy is therefore stored in form of kinetic energy of that rotating mass. Then the MGU is set to generator mode and slows the rotor down, generating electric energy that can be used to power the wheels. Compared to a battery this gives the advantage that it is possible to transfer much higher amounts of energy in a very short time. Keep in mind that an LMP1 race car at mulsanne corner is slowed down from 320kp/h to 80kp/h in about 5 seconds. Thats a lot of kinetic energy that can be harvested in very little time. You'd need very special batteries in order to charge them that fast, and these batteries then need a lot of cooling and cause a lot more wheight. Also, these calculations about capacity can't be right, mostly because the diameter of the flywheel is much less than 60cm. It is more like in the region of 15 to 20cm i believe. It would not make sense to use an energy storage with 14,2MJ capacity anyway. According to LMP1 rules, a car is allowed to recuperate a maximum of 8MJ of energy per lap at Le Mans. Since at LM you get about 7 loading cycles per lap, that means even if you want a bit in reserve you don't need an energy storage bigger than 1,5 or maybe 2MJ.
Hannes Größlinger hi, about that flywheel system i was not suggesting that it is mechanical system but the top gear said it was, because they got an exclusive inside look at it and they described it as purely mechanical system as is said here on page 5: www.topgear.com/uk/photos/nissan-le-mans-racer-lmp1-gt-r-explained-2015-02-09 About energy i know nothing about regulations so you probably are right i did my calculations on assuming it is 60cm flywheel but it is surely much smaller because the whole car is like 1m tall so there is no room for such a big flywheel, so you have your point there i agree :D thanks for some usefull information btw, it is nice to se that, there are someone who still tries to explain you something that he knows about rather just arguing about things he knows nothing about :D
You might be right. I looked into that again, and it turns out there are 2 different solutions on flywheel hybrids on the market. The Williams System in the Audi is electric, as i explained. But there is a second company, called "Flybrid Systems" who work on a purely mechanical version. The flybrid system was also already used at Le Mans in 2011 by the swiss team Hope Racing. BTW concerning the flywheel diameter: that top gear article says that the outer edge of the flywheel is spinning at more than Mach 2, which can't be right since in vacuum there is no Mach number. But if we assume they mean Mach 2 relative to normal ambient air, that would be tangetial speed of around 680m/s and at 60.000rpm that means a diameter of ~22cm.
Hannes Größlinger yes if you use your assumpsion about 1,5MJ storage and 8kg mass, you get around 26cm diameter if you use an equation for rotational kinetic energy, which is similar to what you have calculated ;D
The width of the rear tires doesn't look like it can provide a whole lot of grip when coming out of a turn after power is sent to the rear....I it looks like big wide front tires are gonna be doing all the work provide all the grip pushing in and out of those turns...it most certainly isn't going to have over steer issues and the driver most likely won't have to worry about feathering the throttle trying to find that grip in the rear. Given the agility of LMP1's I don't think being FWD is going to be too much of a problem for it...all I see is grip and good fuel mileage due to the slim rear wheels
So having electric at the back and ⛽ at the front does that mean there is more torque to the rear or just more instant torque making the car more like rwd handling with 4wd traction
Good video and I like your explanation. One thing though, from what I know (I really hope I am correct here as I work for Nissan so if I'm wrong it will be embarrassing) the flybrid system can send power forward as well as rearwards and the car has a very complex AWD torque vectoring system. From the video I was under the impression that you believe the flybrid systems power only goes rearwards. Feel free to correct me if I'm wrong. One thing I don't quite understand is how the air tunnels work and I would be very interested to hear your ideas on the subject of them.
Joseph Topps You are correct, since I made this video they have said that they are currently harvesting and delivering just to the fronts, and have not yet installed the driveshafts to the rear (at least from what I've read to date...). Not sure on where they are at with the AWD torque vectoring system, you may know more than me on this! The air tunnels are a clever way of extracting air from the floor, kind of like an extended front diffuser I guess is the easiest way to explain it... You may want to watch my video on underbody aerodynamics, it explains some things relating to this: ruclips.net/video/HXxkNF2L__8/видео.html Thanks for watching!
Thanks for your reply. As far as I know the propshaft runs high up in the body and it uses to portal axles either side to raise the driveshafts out of the air tunnels. I think the torque vectoring will be quite similar to the GTR road car in principle where an onboard computer does the calculations and adjusts the differentials accordingly. Only in this case it's distributing drive from two different systems combined as opposed to just a combustion engine. I have tickets to the WEC at Silverstone but from what I have heard recently Nissan may not be present because of development issues which I suppose is to be expected with such a radical car.
Ty man, i'm only a child from italy but I understood quite everything. Ty to have try to teach me something more about this car (i'm sorry if i have done some mistakes
Kyle's right, You have to have something different to stand out in racing. That's why Audi raced the diesels, that's why the Bentley's are in PWC. It's when all the cars look the same as in F1 and IndyCar, people lose interest. It's also why in NASCAR you have 3 makes that look different, but have the same draft co-efficient in the wind tunnel before they hit the track All racing works on the same premise - win on Sunday, sell on Monday, always had, always will, no matter if the cars are internal combustion or electric.
FRONT TYRES WILL BE WEARING OUT TOO EARLY!!! On the last two years, Nissan introduced "Delta Wing", a "full rear" project even for mass distribution. This year, they moved into a "full front" one. What are they thinking about? Ok, a full front means more grip on the front tires and a better direction, but... which front tire can last more than 30 minutes in a full front race car? I remember that in the former WTCC, Alfa Romeo was one of the best race car for qualifying, BUT their tires used to be burned after 2/3 of those "sprint" races... AND WTCC had less than 300 Horse Power, much less then the half of a Le Mans Prototype. So, what the hell? Can you imagine in a race lasting 24 hours? Nissan should be pitting every 15 minutes, which means 96 pits in the whole race... brilliant video, you look like an engineer, as I am too, so with quite soft tyres Nissan can make a good qualify for Le Mans, but... race is another thing ;-)
Alessandro Argese A le mans prototype is more focused on aerodynamical grip than mechanical grip, in wtcc you almost don't have any aerodynamic features at all, so the tires need to do a lot more work than on an LMP car.
In practice, it was just different for the sake of it. FWD is inherently shit from a mechanical point of view due to the weight transfer, as he described, and this severely limits how much power you can put down to the ground.
Hey 😊 I've got a question. The new Nissan 2015 lmp1 car use a flywheel to store energy from breaking, but how do they make sure the flywheels speed keeps increasing as the car is slowing? And when they deploy the energy stored, how do they make sure the car accelerates, when the flywheel must be losing speed?
Robin Swann Do you know how a CVT transmission works? By varying the ratio of input or output shaft they can maintain the speed of one of the shafts while the other is accelerating or decelerating.
That would make it all wheel drive wouldn't it? If the rear has axles connected to it to receive power, that would mean it has a capability of being AWD.
I am not exactly a big fan of this car. Because of its thinner tires, there is less contact with the street, so there wont be as much grip. But the bigggest problem is with the aerodynamics: because of the front engine, the "wall" going from the cockpit to the wing is shorter wich results in a smaller surface. And as this is extremely importand for high speed corners, the car will be less stabile than the audis and porsches.
At some point you saying "now" becomes very, and I mean very, distracting.. you should make a drinking game out of it, no one would survive woohoow! Anyway, great explanation!
In retrospective, I'm not sure if it was a successful marketing, considering how it stood out for being awful and unreliable, iirc they even hard to drive without the Hybrid working at all... mentioning the thing is also a sure way to kill the mood at a Nismo event.
No arguments made about driver comfort! I foresee lots of heat coming from the front and into the cabin and poor visibility with all that muscle in the front. I also doubt this will steer as quickly as the other cars.
IMO, the new lmp one form Nissan is just marketing gimme unless they manage to explore some major loophole in the rules. They can't have the ideal floor shape, cause a electrical motor is larger and heavier compare to their petrol counterpart. Unless they have major breakthough so significant all electrical motor are stone tool compare to what they have. I had looked into some commercial off the shelf motor, they all huge and big.sure you can have a high power compact one, but it still big and heavy compare to gas engine and its service life under frequent flat out operation is just a fraction of under continuous power. Plus, ther efficiency sucks. Further more, a competitive design need years of refinement to achieve its competitive stay. Engineers need to learn their own design to make it better (I kid you not). And, without a relatively stable baseline. That refinement is out of window. For the track record, the deltawing was not competitive and even out pace by LMP2 car in som race. But that layout is far more promising than what Nissan have here.
Contents are very good, although a little too quick and a bit confusing at times. Problem is the Australian accent. Hard to fully understand when you are not Aussie
Try watching J lenos youtube channel with the designer of the car. Everything your saying is wrong. According to the guy that actually dedigned the car,the aerodynamics are such that it creats a tremendous amount of downforce on the front end of the car.
dakken74 Look, that guy explain the basic physics. The other explains the results within the limitation of the rules. A lot of shit is going on in LMP, the rule book is so thick it makes laureates and engineers cry.
So it is a front wheel drive but an all wheel drive ..... Ay LMAO, Fucking Nissan with their bullshit, misleading advertising, same way they do when they send ringers to Nürburgring to later trow the stas casually into their production cars. Good video by the way, thanks .
Hey I think you should release a video about the LMP1 GTR after Le Mans since its much different than description in this video its only FWD no power to the rear! let us know whatcha think!
Sean Kandel Good idea! I do get a lot of comments on this video talking about how the current specs are different to the ones when this video was made, so it is probably worth a re-visit...
Great video and very interesting......but the historical follow-up 4.5 years later is a bit painful to read:
"The Nissan GT-R LM Nismo...the car made its racing debut at the 2015 24 Hours of Le Mans. Three cars were entered for the race by Nissan Motorsports, numbered 21, 22 and 23. The cars qualified in the last three places of the LMP1 class with times over 20 seconds slower than the pole position time set by the #18 Porsche 919 Hybrid. The #21 car was actually out-qualified by the fastest LMP2 car. After the three cars failed to achieve a time within 110% of the pole position time, they were demoted to the back of the prototype grid.[29] The #21 car retired from the race after 115 laps with a suspension failure, while the #23 car retired on lap 234 with gearbox issues. The #22 car finished the race, but was not classified as it failed to complete 70% of the race winning car's race distance. The car was never raced again."
On your explanation of the aerodynamic advantages: The other LMP1 cars are mid engined so the rake of the rear diffusor can still start relatively early. But the the mid engined cars also have a front diffusor which i imagine is harder to implement with Nissans front engine.
11:46 "... let's assume it's constant." I am literally unable to assume anything else.
+Keyboard Dancers Mu is a function of load. If the load on the tire increases mu decreases. This is called tire load sensitivity.
+Andreas Bühler Sadly my limited math(s) doesn't really amount to much so I must accept this man's analysis.
Or, you can make an effort to think, watch a couple of videos on simple calculus and what it means to have a function... and expand the limits of your thinking. Does it not sound like something worth doing? Or does self-pitty seem like a better way of presenting yourself to the world.
This didn't age well, the car was a total failure, running almost LMP2 lap times.
your force direction convention is opposite your acceleration direction convention lol. typical vehicle dynamics and free body diagrams would show the forces on the depicted system, so the forces would be reverse of your convention, but your explanations are great
Haha yeah, sometimes you get caught up in the heat of explaining and draw arrows the wrong way and hope people don't notice... It made sense to my mind in the 30 seconds at the time as it couldn't decide to work on force on ground or force on tyre :)
Thanks for watching!
Nice Video. Nice Explanation. I'd like to watch more of you videos but for one reason.
Please improve your audio. The reverb is really annoying. Probably a Headmic would help. It would make your videos even easier to follow and to understand. Literally. Maybe some audio editing would help too.
Sorry for any mistakes in my language. I'm not a natural speaker.
Thanks for your feedback Julian! You may not believe it, but I went to quite considerable lengths to try and clean up the audio on this video, including filling the room I was recording in with cushions to absorb the noise! I do agree that it is a still a problem, perhaps I will have to look at investing into a lapel mic...
Thanks for watching!
KYLE.DRIVES Try hanging a bedsheet in the middle of the room.
SpecialKLSX I ended up buying a shotgun mic, I couldn't find anywhere nice to hang a bedsheet... Tell me if you reckon the audio sounds good on my latest video about the Regera
@@KYLEENGINEERS hi kyle. Do yo have info recommendations (books,papers,thesis,etc) about front wheel drive race car dynamics?
I would like more detailed info on the KERS, energy recovery system, ratios, variations, and current regulations for 2017. Thanx
Fastest acceleration is rear wheel drive only. Ever. Period. Weight transfer is king for the first 60ft, and the first 60ft decides everything.
Le Mans is not about acceleration. It is an endurance race. Long duration durability, fuel economy and tire life are larger concerns in a race like this than any other type of race (they're always important). The ability to dynamically adjust which wheels are using their traction the most is a HUGE benefit to tire life. Regenerative breaking to extend fuel economy is a HUGE benefit.
So the question is much simpler than you represent it. The question is, "Can we build a car that is fast enough to be competitive, and still gain those other benefits of a hybrid powertrain?"
At Le Mans, fastest means nothing. It's a different race with different considerations. This LMP is not designed to be the fastest. It is designed to win Le Mans.
This is also how the Ford GT won in their return to Le Mans -- they didn't build the fastest or best handling car; they designed a car to win Le Mans.
Fastest acceleration would be AWD.
Wrong. The fastest accelerating cars are rear wheel drive. Geometry and traction are not negotiable.
@@ChristnThms I don't see how that makes any sense. All the fastest accelerating cars are AWD.
AWD is rear wheel drive, but with extra power from the front wheels.
But you're wrong, and not doing any research. The reason is weight transfer. At the moment of acceleration, weight transfers from the front to the rear. This is why the front end rises during acceleration. When you accelerate hard enough, the front wheels will come completely off the ground, this completely negating any forward thrust they can provide.
The reason that high performance production cars are often AWD is that the weight and crappy traction provided by street tires doesn't facilitate weight transfer very well. But, even in street cars, RWD is king.
Great video! Very interesting to finally get an explanation on what Nissan means with "better aero packaging"!
This has blown my mind. I have no idea what you just said but thank you for the video. I'll try to get increase my knowledge over time. I'm an avid GT and endurance fan but have very little understanding of the lmp1 classes
Drinking game: every time a sentence opens up with "now", drink!
In the P=F*V part, you state that the force goes down as the velocity increases. This is under the assumption of constant power delivery. So yes, to put the same amount of power down, there will be less force at high speed. However, the required power, to overcome aerodynamic drag scales with V^3. Pdrag_aero=1/2*rho*A*Cd*V^3.
Man this is very interesting, i would have never thought of it this way in a million yrs
Nice explanations, i haven't found a channel that explain as easily the car physics as yours until now ^^
Cheers for making that video, it was very informative. My thinking is that static friction and dynamic friction play by two completely rule books. As these cars are raced on the limit of static friction, tire compound and surface area therefore require a different spec sheet. Nissan are on the frontier of applied physics and this is what excites me the most. Good on them for being so bold.
thanks for very interest and informative videos..admittedly I don't always understand everything your explaining but that's me not your explanation..keep them coming ..love them all
This is actually quite genious. It puts weight on the front axle which is helpful while turning especially in slow speeds where you dont have downforce to make the front work. Also most the power is still going down on the rear than the front so its more efficient use of power. It might be a very oversteery car though when you dont have weight or downforce to put down that 700 electric horsepower.
Great video! Finally more car physics videos! I do have a question that's been bugging me awhile: if surface area doesn't matter why does wider tires give better grip when compared to narrow tires? Assuming that the weight of the tires are the same and mew is constant? Thank you
Glad you enjoyed the video! As I briefly mentioned when talking about balancing the FWD characteristics, tyre area does in fact matter, hence the need for wider tyres at the front. Increasing the contact patch and tyre size raises the amount of total energy the tyre can take without overheating, thus ensuring optimum temperature for optimum Mu. In addition to this, the tyre curves that I mentioned offhand come into play. As the normal loading increases significantly on tyres, the effective mu value will taper off, this is the same reason why weight transfer during cornering is bad and why we want a low CG. Running a wider tyre/bigger contact patch reduces this mu taper as the normal load per unit area is lowered. I can do another video on this if you would like?
Cheers,
Kyle
KYLE.DRIVES I understand, thank you. Another question I've been wondering has to to with car spoilers. I've seen your videos on the subject already but my question is putting a spoiler upside down? Or putting an airplane wing shape to create lift not downforce. Not for racing obviously but for regular cars doing regular driving. My thought process is if you create lift on the front and back of the car let's say driving on the freeway going 75/80 mph, can the wings take off a substantial amount of weight off the car causing an increase in gas mileage? Basically at freeway speeds turning a 4,000pound car into a 3,500 pound car. Thanks for the prompt response
Dr Noro A few things on this point, first you have to differentiate between mass and weight, reducing the force on the tyres does not make the car have less mass i.e. it will still take the same amount of force to accelerate it at a given rate. This is why racecars with considerable downforce can still accelerate so quickly. Obviously the increased rolling resistance from the higher force on the tyres will be a factor, but at highway speeds rolling resistance is a small component of overall losses. What you must remember is producing lift or downforce inherently creates drag, as the up or downwash produces vortices behind you. The most efficient configuration for drag will always be zero lift, zero downforce. Solar car teams often aim for just enough downforce to keep the thing from flying off the road in gusts, but keep this number as low as possible to reduce drag. You may want to look up Sunswift eVe, I have had many conversations with the people who designed the aerodynamics on this car, and it does make a bit of downforce, despite being a world record breaking solar car.
KYLE.DRIVES Amazing. Thank you so much. I have more questions like this but I don't want to overload haha. That makes perfect sense.
Dr Noro I just wanted to add that a usual roadcar already creates lift at higher speeds (certain sportscars of course don't), so you don't want to add to that, because all you want is a stable car. Audi even had to subsequently add a small wing to their first TT generation, because it was too light in the rear at speed.
In my opinion what nissan has done here is the ideal because as well as what's discribed here there's the delivery of power to consider. A petrol engine has to wind up to produce power i.e. there is a maximum amount of torque available at any given engine speed. With a motor however isn't quite the same. A motor, whilst horrendously inefficient at large slip figures, will draw as much energy as possible to reach the point at which motor slip energy draw equals energy consumption. What this means is motors are capable of much better torque curves then petrol engines. So since the rear wheels provide the best grip due to weight transfer under acceleration that's the best place to put the motors. However, the petrol engine provides more power for weight i.e a tank of fuel verse the batteries and so is perfect for doing the majority of the grunt work at higher speeds. Driving through the front wheels has all the advantages described particularly since as described the centre of pressure is being dragged by the front wheels which is more stable then pushed by the rear. Just my opinion. Great bids, really like the way this guy explains stuff.
Lemans protoypes are mid engined, in front of the rear wheels (excluding the nissan of course) a porsche 911 is rear engined, behind the rear wheels.
The nissan is actually mid engined as well, the engine is right behind the front wheels.
Quintinohthree infront of the monocoque. But yes, arguably you are correct.
you did a prety good job of explaining what's going on apart from the part where you are saying it also has an electric hybrid sistem.....i was reading an article about this car (it was top gear i think), where they were told that the hybrid part is not electric but an 8kg rotor located in vacum, so when you brake, the energy instead of charging batteries is used or transfered in to kinetic energy of rotation of that mass (huge rpm's, about 60000 i think), so when they need to deploy that energy it is conected mechanicly to the rear wheels via cluches and drive shafts :D so if i understanded it corectly, energy for braking is harvested and used to rotate the flywheel (accelerating 8kg to 60000 rpm needs a lot of energy), and that kinetic energy (i calculated it at about 14,2MJ if you assume it has 60cm diameter) is sent to rear wheels when needed like a quite big burst of energy :D
i hope you find that interesting and understanded what was i trying to say because i am not native english speaker :D
Yeah I know, sorry, as I made this video the information out on this car was very limited, and most articles stated it was electric with only a bit of speculation about it being a flybrid. Since I uploaded the video it has been confirmed a flybrid, and that is just something I will have to deal with being wrong in the video (might put an annotation on it). Even top gears article released 1 day before I made the video listed it as electric:
www.topgear.com/uk/car-news/nissan-gt-r-le-mans-car-2015-02-02
"Because while the fronts have to cope with 550bhp of internally combusted goodness, the rears have to manage somewhere in the region of 700 electrically generated horsepowers."
This actually isn't the first flybrid car, I believe Porsche had a prototype flybrid GT3 back a bit.
Thanks for watching!
KYLE.DRIVES
Audi uses a similar flywheel system (except with less capacity) in their LMP1 car since 2012.
The system was actually developed by Williams for the 2009 F1 season (when KERS was introduced to F1), however the concept was banned from F1 before they had it race ready. Williams kept developing the system and supplied these units to Porsche (for the GT3 car that almost won the N24 in 2011) and later to Audi (for the cars that won LM24 in '12, '13 and '14).
So the flywheel hybrid is not new, it has been around for some time.
Nissan have not yet revealed if they are also using the Williams system or one from a different supplier. Either way, it is expected to work the same way the Williams system does, and that has nothing to do with clutches or drive shafts like janezick suggested.
The hybrid system works just the same as any other electric hybrid, except that the electric energy generated under braking is not stored in a battery. Instead it is transferred to a motor/generator unit that powers a flywheel. The energy is therefore stored in form of kinetic energy of that rotating mass. Then the MGU is set to generator mode and slows the rotor down, generating electric energy that can be used to power the wheels.
Compared to a battery this gives the advantage that it is possible to transfer much higher amounts of energy in a very short time. Keep in mind that an LMP1 race car at mulsanne corner is slowed down from 320kp/h to 80kp/h in about 5 seconds. Thats a lot of kinetic energy that can be harvested in very little time. You'd need very special batteries in order to charge them that fast, and these batteries then need a lot of cooling and cause a lot more wheight.
Also, these calculations about capacity can't be right, mostly because the diameter of the flywheel is much less than 60cm. It is more like in the region of 15 to 20cm i believe.
It would not make sense to use an energy storage with 14,2MJ capacity anyway. According to LMP1 rules, a car is allowed to recuperate a maximum of 8MJ of energy per lap at Le Mans. Since at LM you get about 7 loading cycles per lap, that means even if you want a bit in reserve you don't need an energy storage bigger than 1,5 or maybe 2MJ.
Hannes Größlinger hi, about that flywheel system i was not suggesting that it is mechanical system but the top gear said it was, because they got an exclusive inside look at it and they described it as purely mechanical system as is said here on page 5: www.topgear.com/uk/photos/nissan-le-mans-racer-lmp1-gt-r-explained-2015-02-09
About energy i know nothing about regulations so you probably are right i did my calculations on assuming it is 60cm flywheel but it is surely much smaller because the whole car is like 1m tall so there is no room for such a big flywheel, so you have your point there i agree :D thanks for some usefull information btw, it is nice to se that, there are someone who still tries to explain you something that he knows about rather just arguing about things he knows nothing about :D
You might be right. I looked into that again, and it turns out there are 2 different solutions on flywheel hybrids on the market. The Williams System in the Audi is electric, as i explained.
But there is a second company, called "Flybrid Systems" who work on a purely mechanical version. The flybrid system was also already used at Le Mans in 2011 by the swiss team Hope Racing.
BTW concerning the flywheel diameter: that top gear article says that the outer edge of the flywheel is spinning at more than Mach 2, which can't be right since in vacuum there is no Mach number. But if we assume they mean Mach 2 relative to normal ambient air, that would be tangetial speed of around 680m/s and at 60.000rpm that means a diameter of ~22cm.
Hannes Größlinger yes if you use your assumpsion about 1,5MJ storage and 8kg mass, you get around 26cm diameter if you use an equation for rotational kinetic energy, which is similar to what you have calculated ;D
Loved this! Thank you! Thought I will recommend some way to get rid of the echo in that particular room. Personal mic, maybe?
Ah, I see you've already had comments about that!
@@icc0017 the echo voice makes me sleepy lol
Its being pulled rather than pushed pulling force is better than pushing force
The width of the rear tires doesn't look like it can provide a whole lot of grip when coming out of a turn after power is sent to the rear....I it looks like big wide front tires are gonna be doing all the work provide all the grip pushing in and out of those turns...it most certainly isn't going to have over steer issues and the driver most likely won't have to worry about feathering the throttle trying to find that grip in the rear. Given the agility of LMP1's I don't think being FWD is going to be too much of a problem for it...all I see is grip and good fuel mileage due to the slim rear wheels
if they just make it where the rear wheels can steer a bit, it can make a huge difference in cornering? as well as making the tires last longer?
So having electric at the back and ⛽ at the front does that mean there is more torque to the rear or just more instant torque making the car more like rwd handling with 4wd traction
im new to your channel. What is the previous video of this video?
Good video and I like your explanation. One thing though, from what I know (I really hope I am correct here as I work for Nissan so if I'm wrong it will be embarrassing) the flybrid system can send power forward as well as rearwards and the car has a very complex AWD torque vectoring system. From the video I was under the impression that you believe the flybrid systems power only goes rearwards. Feel free to correct me if I'm wrong. One thing I don't quite understand is how the air tunnels work and I would be very interested to hear your ideas on the subject of them.
Joseph Topps You are correct, since I made this video they have said that they are currently harvesting and delivering just to the fronts, and have not yet installed the driveshafts to the rear (at least from what I've read to date...). Not sure on where they are at with the AWD torque vectoring system, you may know more than me on this! The air tunnels are a clever way of extracting air from the floor, kind of like an extended front diffuser I guess is the easiest way to explain it... You may want to watch my video on underbody aerodynamics, it explains some things relating to this:
ruclips.net/video/HXxkNF2L__8/видео.html
Thanks for watching!
Thanks for your reply. As far as I know the propshaft runs high up in the body and it uses to portal axles either side to raise the driveshafts out of the air tunnels. I think the torque vectoring will be quite similar to the GTR road car in principle where an onboard computer does the calculations and adjusts the differentials accordingly. Only in this case it's distributing drive from two different systems combined as opposed to just a combustion engine. I have tickets to the WEC at Silverstone but from what I have heard recently Nissan may not be present because of development issues which I suppose is to be expected with such a radical car.
Love the videos, very easy to understand you! Subed for great content!!
Ty man, i'm only a child from italy but I understood quite everything. Ty to have try to teach me something more about this car (i'm sorry if i have done some mistakes
it's 100% FWD now
RIP
Kyle's right, You have to have something different to stand out in racing. That's why Audi raced the diesels, that's why the Bentley's are in PWC. It's when all the cars look the same as in F1 and IndyCar, people lose interest. It's also why in NASCAR you have 3 makes that look different, but have the same draft co-efficient in the wind tunnel before they hit the track All racing works on the same premise - win on Sunday, sell on Monday, always had, always will, no matter if the cars are internal combustion or electric.
Is that The Stig behind the board? :P
FRONT TYRES WILL BE WEARING OUT TOO EARLY!!! On the last two years, Nissan introduced "Delta Wing", a "full rear" project even for mass distribution. This year, they moved into a "full front" one. What are they thinking about? Ok, a full front means more grip on the front tires and a better direction, but... which front tire can last more than 30 minutes in a full front race car? I remember that in the former WTCC, Alfa Romeo was one of the best race car for qualifying, BUT their tires used to be burned after 2/3 of those "sprint" races... AND WTCC had less than 300 Horse Power, much less then the half of a Le Mans Prototype. So, what the hell? Can you imagine in a race lasting 24 hours? Nissan should be pitting every 15 minutes, which means 96 pits in the whole race... brilliant video, you look like an engineer, as I am too, so with quite soft tyres Nissan can make a good qualify for Le Mans, but... race is another thing ;-)
Alessandro Argese The Delta Wing is technically powered by Nissan, and made by All American Racer & Panoz.
Alessandro Argese A le mans prototype is more focused on aerodynamical grip than mechanical grip, in wtcc you almost don't have any aerodynamic features at all, so the tires need to do a lot more work than on an LMP car.
In practice, it was just different for the sake of it. FWD is inherently shit from a mechanical point of view due to the weight transfer, as he described, and this severely limits how much power you can put down to the ground.
Hey 😊 I've got a question. The new Nissan 2015 lmp1 car use a flywheel to store energy from breaking, but how do they make sure the flywheels speed keeps increasing as the car is slowing? And when they deploy the energy stored, how do they make sure the car accelerates, when the flywheel must be losing speed?
Robin Swann Do you know how a CVT transmission works?
By varying the ratio of input or output shaft they can maintain the speed of one of the shafts while the other is accelerating or decelerating.
Great Video!
GTR or GT 40 where would you put your money?
3 numbers 390
Sorry but u are wrong, Ben Bowbly said that the base setting is Full FWD without any rear power, rear wheel drive is only a option & only on staright.
That would make it all wheel drive wouldn't it? If the rear has axles connected to it to receive power, that would mean it has a capability of being AWD.
Themayseffect
it available to have a AWD kit, but it is designed for FWD to a full race, & even in AWD mode, the rear won't help for corner.
I am not exactly a big fan of this car. Because of its thinner tires, there is less contact with the street, so there wont be as much grip. But the bigggest problem is with the aerodynamics: because of the front engine, the "wall" going from the cockpit to the wing is shorter wich results in a smaller surface. And as this is extremely importand for high speed corners, the car will be less stabile than the audis and porsches.
Beautiful
I bet nissan seen this video and just fucking laughed lolol
soooo can a fwd pop a wheelie?
Are you an automotive engineer?
Aerodynamicist I believe
hail STIG
Your draw look great than me!
nissan doesn't use electric power, it uses kinetic. 8kg flywheel
I thought that car used a flywheel to recover wasted energy not electrics? anyway, interesting video all the same. thanks
I would love to knowWHY Nissan stop trying to make this project work... it was stillborn without the hybrid electric element and never worked.
5:58 wheels
Vids would be better with a microphone. Audio is too tinny in this.
At some point you saying "now" becomes very, and I mean very, distracting.. you should make a drinking game out of it, no one would survive woohoow! Anyway, great explanation!
In retrospective, I'm not sure if it was a successful marketing, considering how it stood out for being awful and unreliable, iirc they even hard to drive without the Hybrid working at all... mentioning the thing is also a sure way to kill the mood at a Nismo event.
So 4:42 going through a fast sweeping corner you would get lots of understeer
No arguments made about driver comfort! I foresee lots of heat coming from the front and into the cabin and poor visibility with all that muscle in the front. I also doubt this will steer as quickly as the other cars.
IMO, the new lmp one form Nissan is just marketing gimme unless they manage to explore some major loophole in the rules. They can't have the ideal floor shape, cause a electrical motor is larger and heavier compare to their petrol counterpart. Unless they have major breakthough so significant all electrical motor are stone tool compare to what they have. I had looked into some commercial off the shelf motor, they all huge and big.sure you can have a high power compact one, but it still big and heavy compare to gas engine and its service life under frequent flat out operation is just a fraction of under continuous power. Plus, ther efficiency sucks. Further more, a competitive design need years of refinement to achieve its competitive stay. Engineers need to learn their own design to make it better (I kid you not). And, without a relatively stable baseline. That refinement is out of window. For the track record, the deltawing was not competitive and even out pace by LMP2 car in som race. But that layout is far more promising than what Nissan have here.
It was hilarious to see this car fail as badly as it did at lemans
Yucannt Hahvitt It failed because the hybrid system was never enabled= great big anchor. The design was good.
is all fwd...
Good vid but you used the word "now" 2000 times :)
🤔
I'd say it's because they wanted it to look like a clown shoe.
Wow, 5 years later. It fucking drove like a clown shoe too.
Contents are very good, although a little too quick and a bit confusing at times.
Problem is the Australian accent. Hard to fully understand when you are not Aussie
Try watching J lenos youtube channel with the designer of the car. Everything your saying is wrong. According to the guy that actually dedigned the car,the aerodynamics are such that it creats a tremendous amount of downforce on the front end of the car.
***** So in other words exactly what I said?
+KYLE.DRIVES kids who think they know alot of cars lmao
dakken74 it's also because of the rules limit the amount of down force in the rear
dakken74 Look, that guy explain the basic physics. The other explains the results within the limitation of the rules.
A lot of shit is going on in LMP, the rule book is so thick it makes laureates and engineers cry.
They are driving awd I you were wrong if gtr was fwd it would have to much understeer so it will loose control
Jadyel Torres there are a million and one ways to get a fwd to be neutral under power. balance isnt the issue, its tire temperature and total grip
who brakes on a corner ?????? xD
Nissan is pronounced Knee-sohn. Lol
just take this video down already! its not factual. More power isn`t available to the rear...
I think this car is ugly
So it is a front wheel drive but an all wheel drive ..... Ay LMAO, Fucking Nissan with their bullshit, misleading advertising, same way they do when they send ringers to Nürburgring to later trow the stas casually into their production cars.
Good video by the way, thanks .
ak47law I it's 4 wheel drive only if they connect the electric engine.
Ohh,ok....It makes sense, my bad.
Just BS, watch it will lose.
Hey I think you should release a video about the LMP1 GTR after Le Mans
since its much different than description in this video its only FWD no power to the rear! let us know whatcha think!
Sean Kandel Good idea! I do get a lot of comments on this video talking about how the current specs are different to the ones when this video was made, so it is probably worth a re-visit...