Are Hypercar Engines Better Than Formula 1? — 24 Hours of Le Mans

formula one is too predictable that's unfortunately been true for well over a decade despite my love for the sport but for the first time I went to an endurance race the endurance race mined you as Cadillac invited me to come out and witness the 24 Hours of Le Mans and it was incredible where Formula One has a very rigid rule set surrounding the powertrain Lamar hypercars are much more open so you have much more variance and it's awesome to see these different strategies hello everyone and welcome in this video we're covering the absurdly cool powertrains used in Le Mans hypercars I was able to see Cadillac's powertrain up close while chatting with the engineers it's a 5.5 liter naturally aspirated V8 which is limited by the rules to 500 kilowatts or about 670 horsepower now you might say wait a minute 5.5 liter naturally aspirated V8 making 670 horsepower these are identical stats to the Corvette Z06 engine so is this the same thing no absolutely not not some differences you'll notice right away well just about everything from the Billet valve cover to the 3D printed oil reservoir these are completely different engines despite sounding similar on paper in fact much of the Corvette lt6 engine is defined by its flat plane crankshaft design while the Cadillac has a cross-plane V8 and it actually revs a little higher 8800 RPM rather than 8600 RPM now cross-plane V8 engines tend to have significantly less vibration but you don't really tend to care too much about vibration and racing and yet flat plane crankshaft V8s tend to make more power and you do care about power and racing so why in the world is Cadillac using a cross-plane V8 in this instance well a major difference is how the engine is used with the Corvette Z06 the engine isn't structural and so the engine mounts provide isolation numbing the interaction between the engine and the rest of the car with the Cadillac the engine is structural it's a major part of the chassis and is integral to the handling of the car and because it's structural every little vibration the engine makes is connected to the rest of the car so using a cross-plane crank in this case cuts down on that vibration okay but what about power well power is limited in the rules to 500 kilowatts so maybe a flat plane crankshaft could make significantly more power but as long as you can make 500 kilowatts with your cross plane V8 well you really don't care because you're making that maximum power so it plays less of a role in your decision making so with Le Mans hyper cars sure there are plenty of small rules but when it comes to the engines there's really just one major rule it needs to be a petrol four-stroke engine the end you have so much flexibility so because of this flexibility you see so much variance amongst the cars racing so as far as displacement is concerned you see engines as small as 2.6 liters going up to Cadillac's massive 5.5 liter you've got different layouts you can run a V6 a V8 you can run a rotary engine if you want you've got different aspirations so Cadillac is the only team running a naturally aspirated engine everyone else has chosen to run twin turbos but you have that choice electrification it can be a hybrid if you want it doesn't have to be a hybrid there are teams that aren't running hybrid setups now thinking about naturally aspirated versus turbocharged is a really interesting discussion because if you think about a 24-hour race well you're going to have all kinds of different conditions right sometimes it will be cooler sometimes you'll have higher or lower pressure differences in humidity and so with a turbocharged engine if you're limited to 500 kilowatts well you can very easily make sure you can always make that by adjusting your Boost so if it's hotter outside if you have lower pressure well then you just increase your Boost right with naturally aspirated engines you don't have that ability right but that doesn't mean Cadillac has less power so essentially all that is done is that you ensure that this 5.5 liter V8 can make 500 kilowatts in even the worst conditions and so then anytime you have better conditions than that you're just pulling back a little bit whether that's adjusting timing or your fuel injection you're pulling back the tune there so that you're always making exactly 500 kilowatts and even if you're at an unideal time of day say it's really hot outside you can still make that Peak power and still go very similar speeds right so your speed isn't so much dependent on ambient conditions in regards to how much power you make even with a naturally aspirated engine because you're essentially creating it from the get-go to make sure that in any condition you can make that 500 kilowatt powertrain is also a very interesting discussion so with the Cadillac you have your engine as well as your hybrid motor both connected directly to your transmission now this is a seven-speed sequential gearbox and then that's powering the rear wheels but the hybrid system does not have to go to the rear you could also put it up front the only thing you really have to keep in mind with the rules is is that you have a 500 kilowatt limit at the wheels this is not at the crank of the engine this is at the wheels so you actually have torque sensors on your axles and combined between the front and the rear axle you can never be putting down more than 500 kilowatts of power now as far as the hybrid system at Le Mans you are limited to just 30 kilowatts so it is important to realize that that is included within that 500 kilowatts of maximum power so if you're putting down 30 kilowatts with the mguk well then your engine can only make a maximum of 470 kilowatts but you need to ensure that at any moment you're not using that hybrid motor you still have the ability to have 500 kilowatts just from your engine so the hybrid really is giving you an advantage in efficiency which is critical in endurance racing so it seems crazy that there are teams that aren't using hybrid but hybrid makes so much sense in the endurance environment because again efficiency is so critical in maximizing how many laps you're going to get minimizing how much fuel you're using and time that you're spending in the pits now you might think it it's a very obvious decision to put your electric motor up front because now you have all-wheel drive and with all-wheel drive you get better acceleration at low speeds and you have better performance in the rain right you can put that power down more easily well there is a rule that kind of mitigates how much this Advantage plays to your favor because with the front wheel driven mguks you are limited to using it when you are traveling above 120 kilometers per hour so you don't get that acceleration from a dig and you're not going to get as big of an advantage as far as having all-wheel drive because you're only able to have all-wheel drive above 120 kilometers per hour now power versus energy is also a really interesting discussion so here we're just looking at a simple Dyno plot we've got power versus RPM and as the rules dictate whatever your engine's maximum rpm is you're allowed to make that Peak power of 500 kilowatts at 95 percent of whatever that chosen Max RPM is so there's this find curve right you can only make that Peak power when you're at 95 percent of your Peak RPM and then you have to follow this curve so really you want to keep your RPM as close to 95 as possible somewhere between 90 to 100 but honestly the closer you can make that range that means you're more often making your 500 kilowatts and then there's a very steep drop off if you were to exceed your Max RPM based on the rules you really don't want to do that because you really have to drop off how much power you're making so you're trying to keep it as close to this 95 as possible however you only have seven speeds right and you only have two gear sets that you choose at the beginning of the season for the entire season and you can only use one of those two gear sets so of course that means depending on the track you're going to have advantages in some places disadvantages at others so that gear selection is very critical in trying to ensure that you always keep the power as close to 95 RPM as possible so you can make Peak power now here's is where we have a key difference with formula one so Formula One you have a fuel flow limit in other words you have an energy limit so the more efficient you're able to use the energy flow that you have the more power you're going to make and the more power you make well the faster your car is with endurance racing with these hyper cars you have a strict power limit so the more efficient you are well that means you're using less fuel so you can have less fuel on the car that way you'd be saving weight or you can spend less time refueling your car because you're not using as much of it so that's a time saving so it's a different strategy as far as how do you take advantage of the rules in order to do better in this particular style of racing finally endurance racing has something called balance of performance and Engineers are inevitably going to hate this and fans are probably going to like this so because of all these open rules right there's so many different strategies so many different ways you can go with your car it may be the case that one car will do exceedingly better than the rest right and they don't want to have these major differences in performance because that's not as interesting to watch so balance of performance seeks to equalize this to allow for close racing and minimize any unfair advantages they do this with many different variables so you can add ballast to the cars all of them have to be capable of putting up to 50 kilograms of extra weight onto the car in order to change who has an advantage power is not actually 500 kilowatts as I've said throughout this entire video it's defined by balance of performance to be somewhere between 480 and 520 kilowatts so your team's engine your team's total performance out of the core could be anywhere from 480 to 520 kilowatts at the wheels you also have something called a virtual fuel tank this can be adjusted with balance of performance essentially it's the total amount of energy that you have available per stint per time you leave the pits go out and run around as many laps as you can that total total energy can be changed from Team to team also refueling times so for example hybrids obviously aren't going to use as much fuel so they may be given a slight penalty in the pits where they have to wait a little bit longer so cars that aren't running a hybrid don't have a disadvantage a huge disadvantage because they're not using hybrid and not quite as efficient and have to spend more time refueling in the pits tire sizes can be different there's all kinds of different changes that balance and performance can be implemented in order to make sure you have close racing now there are very obvious challenges when bringing up balance of performance right because inevitably you are going to penalize good engineering like how do you not how do you not penalize a team that designs something perfectly has this really fast car it beats everybody well now it's going to get taken down so that it's More Level Playing Field sandbagging is now going to be inevitable now they try to get around this by using simulation data rather than just looking at the cores and saying okay which one's the fastest they look at simulation data based on the cars based on the car's capabilities and say okay who should be the fastest and in what scenarios and how do we make it so that everyone's going to be relatively close but ultimately the whole goal of all of this is so that the racing is close and that it's entertaining to watch right this is entertainment the whole purpose of racing is entertainment and so balance of performance seeks to maximize entertainment and so when I think about you know when I started watching Formula One well Sebastian Vettel was winning pretty much every race and he had his dominant era and then that went to Mercedes and Lewis Hamilton won most of the races it was just his dominant error and it was very predictable okay Lewis Hamilton's probably going to win and now today Max verstappen wins most of the races right it's very predictable Whoever has the best car Formula One is very much so an engineering Sport and so whoever has the best car has a significant advantage over the rest of the field and is going to be the more likely one to win the race so what's cool about endurance racing is they seek to minimize these dominant errors and they really want it so that it's not predictable from the start of the race who's going to win that race yes there's going to be controversy surrounding it always that is just inevitable with how kind of finicky trying to tweak the rules so that cars are close it's just going to be that way but it's very entertaining admittedly to watch so thank you all so much for watching and if you have any questions or comments feel free to leave them below

Channel: Engineering Explained

Views: 434,432

Keywords: 24 hours of le mans, cadillac, cadillac lmdh, cadillac v-lmdh, cadillac v series, formula 1, formula 1 engine, 5.5L v8 engine, v8 engine, v8 vs v6 engine, formula 1 vs wec, wec, engineering explained

Id: O245IDby_pU

Length: 12min 29sec (749 seconds)

Published: Fri Jun 30 2023