The New Porsche 911 GT3's Engine Is A Masterpiece

hello everyone and welcome in this video we're talking new porsche 911 gt3 and more specifically diving into the details of its glorious 4.0 liter naturally aspirated boxer 6-cylinder engine and so that it's abundantly clear a portion of this video is sponsored by mobile 1 however this is not in any way sponsored by porsche now i don't know what the perfect engine is i think there's an argument to be made for any high revving v8 v10 or v12 and growing up i was a ferrari fanboy and just assumed everything they did was the best and one day i was lucky enough to get the opportunity to drive a 4-5-8 and a porsche gt3 back-to-back and i'll be honest i was looking forward to the 458 much more than the gt3 and yet once i actually drove them i found myself suddenly drooling over the 911. it was better in my opinion and to my surprise it even sounded just as good as the 458 screaming v8 at the heart of the 911 gt3 is a masterpiece of an engine in today's world of excessive numbers 500 horsepower might not sound like all that much and yet this 500 horsepower is enough for the 911 gt3 to outlap its much more potent rivals on the nurburgring like the mclaren 720s or ferrari 488 hosting a sub 7 minute lap time equally impressive it's only seconds behind the nearly 900 horsepower porsche 918 and the nurburgring is a high speed track power definitely matters here so how have they done it well let's talk a little bit about why this engine is so impressive and to do so i'm going to compare the 4.0 liter boxer 6-cylinder to a twin-turbo v12 used in the rolls-royce ghost now obviously these are completely different applications one wants to be very fast and the other wants to have enough power so that the driver or more likely rear seat passenger doesn't feel like they've wasted 400 thousand dollars on a car that's super heavy the point is both cars want lots of power they just want it for different reasons so porsche's naturally aspirated boxer 6 makes 502 horsepower and 346 pound-feet of torque in 2015 the rolls-royce ghost engine was making 563 horsepower and 575 pound-feet of torque of course the rolls-royce is making more power and torque it's bigger and it's turbocharged but what if you start to compare them on a per liter basis so let's say we have a one liter single cylinder engine that represents our gt3 engine because it's naturally aspirated it's pulling air into that cylinder that starts at atmospheric pressure so in an ideal world this engine can pull in and fill up this cylinder with atmospheric pressure ultimately this amount of air is mixed with the correct amount of fuel and that creates a certain force to push the piston down the more air and fuel the more potent the combustion and thus the greater the force the gt3 engine is capable of creating 86.6 pound-feet of peak torque for each leader of the engine so our one liter representative example here is making 86.6 pound-feet of torque now this is where the rolls engine has a huge advantage because it's turbocharged so the engine starts with the ability to bring in at max atmospheric pressure then on top of that the twin turbochargers act as compressors forcing additional air in meaning we now have more air than atmospheric pressure more air we can burn more fuel and thus we can make a greater force pushing down that piston and yet when this rolls engine is operating at peak torque that force only translates into 87.2 pound-feet of torque not even a single pound-foot over the naturally aspirated porsche engine if you want to dive into engineer nerd talk the porsche engine has a brake mean effective pressure of 14.8 bar while the rolls engine is just 14.9 bar this being the average pressure forcing the piston down during the power stroke how can they be so close the answer here isn't that the rolls-royce engine is garbage the 6.6 liter v12 is made by bmw a company quite capable of producing fantastic engines like this v12 but it does help illustrate just how impressive the gt3 engine is the secret to porsche's potency is that naturally aspirated engines aren't actually limited to atmospheric pressure with the right design naturally aspirated engines are capable of achieving a 10 to 15 percent increase over atmospheric pressure in the cylinder potentially even slightly higher under perfect conditions this is by no means easy which is why this porsche engine is so impressive i only know of one other naturally aspirated production car engine making more torque per liter and that's the ferrari 458 so how does porsche do it well for starters they're using a variable intake manifold with two switchable resonance valves and six individual throttle bodies when an intake valve opens the low pressure within the cylinder creates a suction wave traveling back through the intake runner which can be reflected back as a high pressure wave also when an intake valve closes the air rushing into the cylinder is suddenly cut off building a high pressure area near the intake valve that then bounces around as a pressure wave inside the manifold if you were to take a single point on an intake manifold and measure the pressure you'd find the pressure wasn't perfectly constant but has some fluctuation as the pressure waves bounce around inside the manifold you can use this to your advantage if you have the high pressure wave time correctly it will help force additional air into the cylinder before the intake valve closes essentially providing a bit of boost to your naturally aspirated engine with a boxer engine you can have pressure waves bounce back and forth between the cylinders helping each other out now the problem is this will only be optimized for certain engine speeds or rpm here's where porsche's solution comes in they have two resonance valves to manipulate the resonance frequency of the intake system so they can optimize for different rpm i found a patent filed by porsche in 2005 that describes how a system like this works though that doesn't necessarily mean it's exactly what's happening in the gt3 engine the patent describes an intake manifold that has two connecting pipes and each connecting pipe has a throttle valve which allows it to connect or disconnect the two cylinder banks from each other at low rpm say up to 3000 rpm both connecting pipe throttle valves are closed so air comes in and is split between the two chambers at mid rpm say between 3000 and 6000 rpm the first throttle valve opens fully changing the resonance frequency and allowing for dynamic supercharging and thus better filling the cylinders then at high rpm for example above 6000 rpm both throttle valves are opened allowing for optimization for high engine speeds porsche also employs variable valve timing for both the intake and exhaust valves so they can manipulate the valve timing throughout the rpm range so the pressure waves match up as closely as possible to the valve timing to optimize torque and it doesn't simply end there as this is a high revving engine the airflow within the intake manifold starts to move very quickly at high rpm like 9000 rpm in the porsche airflow is at its peak and this air mass has inertia to take advantage of this you can time the intake valve to close during the compression stroke meaning the piston is moving up but the inertia of the incoming airflow is such that it will continue to pump air into the cylinder before closing off the valve and the complexities don't end there in addition to a central throttle valve as well as the two within the intake manifold each individual cylinder has its own throttle body individual throttle bodies can not only optimize efficiency but they can also mean a very short path between atmospheric pressure to the intake valves assuming the main throttle valve is open which optimizes engine response because the air doesn't have to travel far to enter the cylinders now i mentioned 9000 rpm and while there are a few exceptions this is among the highest rpm you'll see used in production car engines porsche uses a very wide bore with a relatively short stroke to allow for the high engine speed the wide bore means they can use big intake valves so airflow is no problem at 9000 rpm a fun example the audi r8 v10 actually has pistons that move faster than the porsche pistons i believe the fastest of any production car engine and yet the porsche engine is actually able to rev higher an additional 300 rpm over the audi thanks to using a shorter stroke to further ensure that the timing and robustness of the valve train is optimized for high rpm use instead of today's commonly used hydraulic lifters porsche actually uses rigid mounted lifters technology that is often more commonly used in racing where engine rpm is so high and the valve clearance is set manually using shims so you're wondering wait a minute i now have to manually adjust my valves again according to porsche nope the valve clearance is set at the factory with shims and it's designed to last the life of the engine how can it last so long the rocker arms have a diamond-like carbon coating providing an outer layer that is as the name implies a bit diamond like it's very hard very wear resistant and very slick and of course even more so once coated in oil speaking of oil engines that are revving to 9000 rpm with high g-forces from cornering like you might experience on a track need to make sure oil is circulating regardless of what the car is doing that's why the engine comes with a dry sump oil system with seven scavenge pumps meaning seven areas of the engine it can pick up oil from what kind of oil well a quick shout out to my partners at mobile one they've been a great supporter and sponsor of engineering explained and mobile one comes factory filled in the new porsche 911 gt3 in fact more than one million porsches have come factory filled with mobile one over the last 25 years mobile one is protecting that engine whether it's sitting in traffic in los angeles or setting sub 7 minute lap times at the nurburgring and on that lap time it's genuinely mind blowing there's only one production car and there should be a serious asterisk next to the word production there that has less power than the gt3 and a faster ring lap time and that's the radical sr8 an open cockpit car developed obviously for track use and while the porsche has about a 50 horsepower advantage it's also nearly double the weight of the reticle and yet has a lap time several seconds behind i wouldn't exactly call the radical sr8 a production car and thus you're looking at what is possibly the fastest production car around the ring with 500 horsepower or less weight is kept down to just 3126 pounds or about 1400 kilograms even though the car is 1.9 inches wider than the standard 911 this is thanks in part to a hood and rear wing made of carbon fiber reinforced plastic lightweight noise insulated glass and titanium engine components and great news for the elitist manual snobs like myself and many who watch this channel not only is there a 7 speed ultra fast dual clutch transmission porsche's pdk but they are also offering an optional 6-speed manual transmission how beautiful something that is nearly extinct among cars in this price range so yes there's still a car worthy of the aspirational high schooler's bedroom wall or okay fine esteemed and mature adults such as myself that are capable of recognizing the fine art that is manual driving who am i kidding i daily an electric car because i'm a loser but i do quite appreciate companies still willing to pump out manual transmissions whether it's a track focused porsche 911 or true enthusiast's wildest dream car like my subaru crosstrek wait maybe i really am a loser the handling of the gt3 is improved thanks to a multi-link rear suspension and double wishbone front suspension and none of these parts are carry over from the standard 911 of course there's no grip without tires and the gt3 now offers optional michelin cup 2r tires basically a street legal track tire and the sub 7 minute ring time was also set using cup 2rs the final element of grip the gt3 comes with manually adjustable aerodynamic elements significantly improving downforce even in the normal street use setting down forces up 50 percent over the previous gt3 and in the track position applied both front and rear downforce is increased by 150 percent anyways i'm going to go back to my supercharged mx5 and continuing to tell myself that it's just as fun while occasionally looking at that bedroom poster of the new gt3 with concealed envy what an incredible machine 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: 789,701

Keywords: porsche, porsche 911, porsche 911 gt3, 2022 porsche 911 gt3, boxer engine, 4.0l engine, naturally aspirated, best engines, best engine, best porsche, best porsche 911

Id: 8xByM10KM2k

Length: 13min 17sec (797 seconds)

Published: Wed Feb 24 2021