How Tiny Formula 1 Engines Make 1000 HP!

hello everyone and welcome in this video we're going to be explaining how the tiny engines used in Formula One are capable of producing 1 000 horsepower now the current generation of Formula One engines started in 2014 as a general overview you have air come in through the intake pass through the compressor side of the turbocharger of course that heats up that air so it then passes through an intercooler this can be an air-to-air or an air-to-water intercooler that cooled air then passes into the cylinders where it's used for combustion the exhaust of course exits helps spool up your turbocharger and then goes out the exhaust at the back of the vehicle so the specifications are set in that this must be a 1.6 liter 90 degree V6 engine and your bore is set at 80 millimeters which essentially means your stroke is set at 53 millimeters giving you a per cylinder size of 0.267 liters so this is about half the size of the cylinders used in today's production course which tend to sit about half a liter for their cylinder size this engine revs up to 15 000 RPM that is the we'll get into why later on in the video so we have two clever additions to this Formula One power unit they are both electric motors one of which is called an mguk which is directly linked to the vehicle's crankshaft and one of which is called an mguh which is directly linked to the turbocharger shift and so as you can imagine if you have a turbocharged engine as you start to create more exhaust gases you start to produce more boost which means you create more exhaust gases which means you create more boost and that just runs away right you have to have a solution to this so in traditional turbocharged engines we use wastegates so we can allow some of that exhaust pressure to bypass the turbo and thus not have this endless feedback loop where we continuously build boost now you can use wastegates in Formula One but there's a more clever solution in order to harness as much energy as possible instead of wasting that energy going out the exhaust so instead of wasting that energy you can use that energy to spin up this mguh this Electric motor which is connected to that exhaust portion of the turbocharger as well as the intake and so as you spin this motor up it can act like a brake it's essentially like regen from your turbocharger so you're using this to break that Force that's trying to spool this up further and keep it at a certain level of boost and then that energy that this harnesses can then be sent to a battery or to the mguk so your mguh essentially serves three purposes you can use it to keep your turbocharger spooled up when you're off throttle basically acting like anti-lag you can use it to charge the battery there it's basically acting like a wastegate and limiting how much boost you can create and that's harnessing that energy and sending it to a battery so you can use that energy later and then you can use it to directly power the mguk so sending its power to the mguk which is directly linked to the crankshaft in order to get more acceleration at the wheels now your mguk has two basic functions first of all it can be used to send 120 kilowatts of power directly to your crankshaft so giving you greater acceleration or you can use it to use basically like brakes it can be used for regen so negative 120 kilowatts or in other words you're using the regen to send 120 kilowatts of power from the mguk back to the battery to save that energy for later use so if our mguk is making 120 kilowatts or about 160 horsepower that means in order to get to a thousand horsepower for the overall unit we've got about 850 horsepower coming from the engine alone but how is this actually possible so as far as powertrains are concerned there's basically two rules that run the show in Formula One the first is you have a total limit of 110 kilograms of fuel that you can have stored on your vehicle so this is how much energy you have in order to complete the race so you have to complete a set number of laps whoever does it in the least amount of time that's basically your goal and you're given 110 kilograms of fuel and order to do it so the more energy you have the faster you can complete this task but everyone has the same amount of energy 110 kilograms of fuel now as far as the second rule that comes down to fuel flow so there is a cap on how much fuel you can have going into your engine which is dictated by this equation here fuel flow is equal to RPM times 0.009 plus 5.5 with a limit of 100 kilograms per hour so you can never have more than 100 kilograms per hour of fuel going into your engine so what is this equation look like when you plot it out well basically it's a linear function and it caps out at 10 500 RPM so at 10 500 RPM you're allowed to use this maximum fuel flow of 100 kilograms per hour this is why you don't see engines running up to 15 000 RPM there's really no reason to do it so if you were to plot out power using this fuel map up you can't use more fuel above 10 500 RPM you're limited right so why would you go to a higher RPM because you're just going to have more frictional losses yes you can get more air into the engine but you can't put any more fuel into the engine so there's no real reason to do it so you'll see driver shift at say you know 12 000 RPM they're going to want to keep it within the peak of the power range which is going to be you know Peak power is going to be somewhere around like 10 500 11 000 RPM where you achieve that Peak and then you want to use your gears to keep you within that as you go through the race okay so we still don't understand how we're able to achieve a thousand horsepower so what do we know well we know that our power is ultimately limited by Fuel we can never exceed 100 kilograms of fuel per hour so how much energy is in 100 kilograms of fuel well we know from teams they state that the fuel used in Formula One is 99 the same as the pump gas that we're already used to so the EPA states that one gallon of gas is equivalent to 33.7 kilowatt hours one gallon of gas weighs about six pounds or 2.72 kilograms so we can take a hundred kilograms which is our limit divide that by 2.72 and that means we have about 36.8 total gallons of gas and if we use our EPA conversion rate we multiply that by 33.7 kilowatt hours that means the total energy we have within 100 kilograms of gasoline is 1 240 kilowatt hours now that's just some napkin math why should you believe me right well I found a Mercedes document which states in 100 kilograms of fuel the total energy content is 1240 kilowatt hours now they actually State kilowatts which is a unit of power not energy but again keep in mind this is a mid-pack team let's cut them a little slack I'm kidding chill out okay so we know that our engines are limited in power by Fuel which is limited to 1240 kilowatt hours per hour in other words our engine has a limit of 1240 kilowatts now that would be if we were operating at 100 thermal efficiency we know these engines can exceed 50 thermal efficiency so dividing that number by two meaning our engines can create 620 kilowatts or about 830 horsepower plus 120 kilowatts from our mguk giving us a grand total of about 740 kilowatts in other words about 1 000 horsepower now naturally your next question might be well how in the world are they achieving 50 thermal efficiencies it's impressive for today's internal combustion engines to reach 35 thermal efficiency so how are these so much further in efficiency well there's three pieces of technology that I want to discuss the first one being pre-chamber ignition so if you think about today's combustion engines when they're making maximum power when you floor it in your car and it's making maximum power it might be using an air fuel ratio of about 11 to 12 to 1. this means it's running rich in other words there's more fuel injected into the combustion chamber than you can possibly burn this is ideal for making maximum power but if we're thinking about Formula One where we're limited on our fuel flow and we're limited on how much fuel we have well then it's really dumb to use a rich mixture because it means some of that fuel isn't going to be used we want to use it as efficiently as possible so how can you run a leaner air fuel mixture in your engine well that's what pre-chamber ignition helps achieve so you basically have two combustion Chambers a really small one next to your spark plug and the larger one the one we already know with our piston cylinder devices so what happens is with formula one you're allowed one injector per cylinder so this is a passive chamber you have direct injection that direct injector is very close to our little pre-chamber right here and so you have a richer air fuel mixture next to that spark plug thanks to the timing of your direct injection and the rest of the cylinder so the rest of the cylinder is going to be a bit more lean so this Rich pocket right next to the spark plug is going to start to combust it'll create these little turbulent jets that expand out very quickly and help to combust that leaner air fuel mixture now a company Molly which creates turbulent jet ignition engines says with a passive system like this you can get away with high loads with a air fuel ratio of 14.701 with an active system meaning you were actually to have another fuel injector within this tiny little pre-chamber well then you could achieve air fuel ratios of about 30 to 1 Lambda 2. so this of course is a passive system in Formula One but it means you can use leaner air fuel ratios than we're used to in our combustion Vehicles okay the second part of efficiency for F1 engines within the rules it is stated that you are are limited to a geometric compression ratio of 18 to 1. now we don't have production gasoline road cars using 18 to 1 compression ratios it would be very efficient the higher your compression ratio the greater your efficiency but what happens when you start to get in these really high compression ratios well you run into knock and it destroys your engine but you can have some clever tricks if this is your limit so I don't know what they actually do in Formula One I don't know what the compression ratios teams are using are but here's just an example of what you can do with something like an 18 to 1 geometric compression ratio so you have your intake stroke occur you close your intake valves early that means once your intake valves are closed your piston continues to move down so your compression stroke is actually limited by when that intake valve closed so it's not that high let's say it's 15 to 1. so you compress all of that mixture then you have combustion occur your cylinder your piston starts to come back down 3 reaches its initial compression ratio meaning 15 to 1 in this case we're talking about our expansion ratio but we have further distance that we can travel we still have pressure within that cylinder and so we give it a little bit more distance that that piston can travel and thus we can extract more energy out of that exhaust so that is a more efficient way of operating now it is worth mentioning that within Formula One there is no variable valve timing there is no variable valve lift so whatever you choose to do it is set so you're typically going to probably choose an RPM 10 500 RPM 11 000 RPM something like that to have your most efficient operating Point as far as the design for the engine of making power and so your fixed your valve timing is going to be fixed this is kind of where you get into those like discussions where people say oh like Formula One is the most brilliant technology that's ever been invented it's like all engineering is very cool based on its rule set right like production cars have a complete different set of rules than Formula One cars both of them have ingenious engineering included within them so comparing them and saying one is better than the other that's a bit silly like if you could use variable valve timing variable valve will lift things like active Chambers it's like these are technologies that exist and are better than What's Done in Formula One they're not allowed to do it based on their rules okay so finally we get to the third part of this efficiency discussion which is our mguh so there is still some exhaust gas pressure remaining of course within that cylinder once combustion has finished that exhaust is used to spool up this turbocharger and it's also used to put energy back into the battery using that mguh so using the mguh you're able to harness some of that energy that would otherwise be wasted with this style of combustion engine now I wanted to find a bit more concrete evidence for efficiency claims discussed in Formula One and so I came across a study on lean pre-chamber gas saline engines which just so happened to be co-authored by a former 15-year Renault Formula One engineer who according to his LinkedIn was responsible for Hybrid engine specifications both ice and mgu and responsible for 3D cfd engine simulations injection mixture preparation combustion knock in this study it stated 47 Peak thermal efficiency achieved at Lambda equals 2.1 with the gasoline fed pre-chamber and indicated thermal efficiencies above 48 can be expected with a realistic electrified turbo charging system hmm what does that sound like so they're expecting close to 50 percent thermal efficiency using pre-chamber ignition as well as electrified turbocharger systems now something I've always wondered is we've got these tiny engines just 1.6 liters and they're making about 850 50 horsepower so how much boost are these turbochargers actually providing and I've not been able to find a legitimate source that states you know what this boost level is so let's try to calculate it so we know that our fuel flow is 100 kilograms per hour what is our airflow well let's just start off assuming a naturally aspirated Engine with 100 volumetric efficiency in other words we have our 1.6 liter engine it's revving at 10 500 RPM we're going to multiply those together that's going to give us the total amount of airflow going through it divide that by two because we only have one intake stroke per 2 RPM and that means going through our engine we have 8 400 liters per minute because the metric system is beautiful that means we have 8.4 meters cubed per minute now we can multiply that by air density at sea level so if we were at sea level the amount of air going through the engine at 10 500 RPM with a naturally aspirated engine would be 10.29 kilograms per minute now we know our fuel flow is 100 kilograms per hour so let's get our airflow in terms of kilograms per hour simply multiply this by 60 and we get 617.4 kilograms per hour okay so our air fuel ratio is our airflow divided by our fuel flow so we have 617.4 divided by 100 that gives us an air fuel ratio of 6.17 now this is extremely rich right we're injecting way too much fuel or we need to inject a lot more air using boost using our turbochargers so ideally our air fuel ratio would be 14.71 that's the ideal stoichiometric air fuel ratio so if we take 14.7 divide it by 6.17 that gives us the amount of air which we would need to have an ideal ratio which would be 2.38 atmospheres in other words our absolute pressure would be about 35 PSI or 2.4 bar meaning our boost pressure subtracting our atmospheric pressure would be 20.3 or 1.4 bar so a boost pressure for this 1.6 liter engine making 850 horsepower is only 20 psi that seems incredibly low so kind of the reality check on why this number is so low and I do think it's probably lower than I expect two reasons first of all it's a high revving engine the higher you rep the more power you can make per liter but again you're limited by that fuel flow right so the other huge part of it is that it is so efficient so you know you may have a modern turbocharged engine running really high boost in order to make significantly less power than this but it's operating at such a low efficiency so because it's so efficient and because it's really efficient at a really high RPM it's able to achieve a really high power number using a low amount of boost on a relative scale now we don't actually know what the pressure is Within These engines because we don't actually know what the air fuel ratio is maybe they're able to get closer to say a Lambda to I don't think they're going to go that high but let's just say for example they were able to use an air fuel ratio of 1.5 what is ideal 1.5 times what is ideal mean a very lean air fuel ratio about 22 to 1. so we take our 22 divided by 6.17 we get 3.57 atmospheres in other words our boost pressure here in this case would be 38 PSI or 2.6 bar quite High and the reason being is because you're running really lean and so to run really lean you inject a lot more air within that cylinder than you actually need so that you can run the engine in a way which you have found to be the most efficient now one final comment on what this boost pressure might be again I don't know what it is but my best guess would be between these numbers right here based on what air fuel ratio it's using but one thing you need to keep in mind is this is going to change depending on the circuit so if you're at a really high elevation circuit like Mexico City well then you're going to have a higher boost pressure because the air is thinner so you're going to use the turbocharger to compensate for that to compensate for that low atmospheric pressure base that you're starting at so hopefully you've learned something here about Formula One engines thank you so much for watching and now I would recommend using the comments section to explain why the team that you're rooting for is so much better than everyone else and also congratulations to Max verstappen on winning the 2023 Formula One championship

Channel: Engineering Explained

Views: 1,362,375

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Id: KjrNcuc89Pc

Length: 18min 47sec (1127 seconds)

Published: Fri Mar 03 2023