The Combustion Engine Perfected - Porsche GT4 RS

let's see what a little bit of a launch feels like [Music] it's so good hello everyone and welcome we are sitting inside of the porsche cayman gt4 rs so what is special about this vehicle is that it takes the engine out of the gt3 the 911 gt3 and they put it inside of the cayman so that is a four liter flat six naturally aspirated revs to 9000 rpm and making 493 horsepower and as you can see we are on a track however as you can also see i am not wearing a helmet so we're going to be treating this like i'm driving on a road i've already done uh some nice healthy track stints on it where it really pushed the vehicle to get to know the car so now we're just going to be talking about it what it's like some of the engineering behind it and what it's like to drive so this engine 493 horsepower now you'll notice it's about 10 horsepower down from the 911 gt3 so did they intentionally detune this no that's not what happened so what happens is they've turned the engine and the transmission 180 degrees so the engine is now in the middle rather than at the rear and that means you have a different exhaust path so you have to turn that exhaust around when you turn that exhaust around you then have to route it up and over those rear axles and as a result of that pathway you have some additional pressure losses in that exhaust it's basically unavoidable because of the bend you have to make within it and so as a result you make just slightly less power certainly still plenty and it is a very noticeable difference from the gt4 you've got individual throttle bodies with this engine it is extraordinarily responsive and i think uh that's probably the biggest thing that you notice is the amount of control that you have with this engine with the throttle and with the combination of this just beautifully tuned naturally aspirated engine there's two things that i think this car does really well that many modern cars do not uh and it's almost ev like in that sense and what i mean by that is you have really good response so when you put your foot down get that power very quickly you also get exactly what you asked for so if you ask for 50 you get 50 100 you get 100 so it does that very quickly and you don't have really any perception of a delay aside from a gear change if you're sitting in a low gear like i am now but in a track situation where you've got in the correct year second you put your foot down you get that power and when you're at sixty percent you ask for a hundred percent you get that immediately that is something that you know is rare in the combustion world um and porsche just nails it with this engine so i really like the responsiveness from the engine as far as the acceleration 0-60 in 3.2 seconds so versus the standard gt4 with the manual transmission this is a full second faster to 100 kilometers per hour and versus the gt4 with pdk this is half a second faster to a hundred kilometers per hour and so that's two reasons significantly more power and also more aggressive gearing finally i think everyone's prayers have been heard in that we have a very aggressive gearbox in a cayman gt4 this is what porsche says is the most aggressive gearing used in any porsche gt car so this is the gearbox out of the 911 gt3 rs the previous generation and they've stuck it in here matched with of course that engine and so you might wonder okay is it that simple it's not that simple so when you turn the engine and the transmission around making mid engine car instead of a rear engine car that of course means turning the transmission around which means you would have seven reverse gears not seven forward gear so is there is some rework involved in making this transmission work but it is a very aggressive transmission and the core has more power so as a result it is significantly quicker i mean 0 to 60 and 3.2 seconds again going back to this it's almost ev like and this is a combustion engine we're talking about so it's rear-wheel drive and it's getting these insane 0 to 60 times with a combustion engine and it has this insane response with a combustion engine so it's kind of showing you that a combustion engine can do it all uh in this day and age with all the modern engineering and tuning that goes into it now the top speed of this vehicle is a hundred and ninety six miles per hour and as porsche hey we're like were you targeting anything was 200 miles per hour in consideration they said no we don't really care what the top speed is for this car we're just trying to make it you know a really fun really enjoyable car to drive and you know the top speed is simply a factor of how much power does it have what are the aerodynamic drag and what's your gearing and so as far as the gearing in the standard gt4 you reach your top speed in sixth gear and then you have a seventh gear as an overdrive and this car again going back to that aggressive gearing which i love they're giving you your top speed and your final gear so you're reaching that in seventh gear and that 196 mile per hour is simply a factor of you know how much power do you make how much drag do you have and your gear ratio so that's where you end out at 196 miles per hour so we've talked about the engine we've talked about the transmission moving to the differential it uses a mechanical limited slip differential they did look into potentially using an electronic style limited slip dip ultimately that would mean changing the entire transmission housing and there was a lot of rework required and then you start to get into gt3 territory so they thought you know for the scope of this project that didn't make sense to do they're trying to keep this thing kind of pure kind of analog a driver's machine and not kind of broaden the scope of the project way too wide so from those differentials going out to the wheels and brakes the brakes are larger than the gt4 and they have also changed the rear caliper pistons in order to improve trail braking they've also increased the precision of the abs system now as far as the tires this is the first time in a cayman you can get michelin cup 2 r tires so extremely grippy tires uh finally offered on the cayman gt4 and these are porsche specific tires so they've worked with michelin hand in hand in order to create uh you know the the right compound and the right features of this tire to suit this vehicle as far as the wheels it comes standard with aluminum wheels you can also get optional magnesium wheels and porsche was asked you know why uh not use something like carbon fiber and i thought they had a really interesting response as far as using carbon fiber for wheels several things made them concerned first of all brake temperatures getting into you know 800 degrees c or so that heat can damage those wheels it's not good for carbon fiber to get really really hot in addition to that these are track cars right like these are meant to be thrown around on a track and you might find yourself in a gravel pit and that gravel can then hit that carbon fiber it could cause internal damage that you don't see and then you're you know reducing uh the the structural integrity of that wheel and you may not be able to actually know that visually looking at it and then finally and i thought this was really interesting carbon fiber requires a bit larger spokes so you can't have these thin very aesthetically pleasing spokes like you have with the aluminum or with the magnesium wheels and it really does look good especially with those center caps and you've kind of freed up that real estate to make a good looking wheel so this gt4 rs is 23.6 seconds faster on the nurburgring than the gt4 and there's a lot of reasons for that has significantly more power has better tires has better gearing has better suspension uh porsche says the cup 2r tires versus a cop2 tire are worth about five to six seconds on their evergreen alone pretty impressive what you're getting out of these tires now as far as the suspension uh this is really a no compromise kind of track focus suspension here where they have nearly doubled the rear spring rate stiffness and more than doubled the front spring rate stiffness so quite a bit stiffer than the gt4 and what i've been surprised by is you know yes this is a smooth track and you're not really going to notice it all that much compared to a harsh bumpy road but the ride is actually pretty well controlled and that's what you can do with modern damping you know they've got different damping settings you can select here and it is really impressive to me how stiff these springs are and yet you know how comfortable this has been going around the track you also have all ball joints for the suspension so you know they're not really compromising in terms of comfort if there was a decision to be made between hey do we make the car more comfortable or do we make it more fun to drive make it more sporty to drive it always went towards more sporty i mean that's why you have these like you know little straps for handles right the compromise is made to make this thing more fun to drive that's the name of the game that's part of why you have this air box right behind me that's exposed and i get to listen to this engine when i put my foot down i mean it's a beautiful sound and it's right in your face because it's right there and porsche said that was one of the biggest challenges in developing this car because that could also provide you know negative sounds to you so what they really had to focus on is making sure that you got the joy from that engine but you didn't hear the bad parts i mean this is a large surface area you've got these six pistons pumping it kind of acts like a subwoofer uh and so they had to do a lot of tuning with this uh you know air filter cover to make sure that these materials didn't cause bad vibrations and cause you know that loud uh subwoofer sound within the cabin depending on where your foot is on this throttle so it's pretty clever and the end result is you get to hear beautiful engine sounds right inside here i mean it's in your face now as far as the car overall this vehicle weighs about 50 pounds less than the standard gt4 so they have taken weight out there's a lot of use of cfrp throughout the vehicle whether that's up front or the rear wing using that for the seats as well a big focus on getting the weight out and you know making sure lightweight just makes everything better right even the rear windshield is thinner in order to pull some weight out now as far as aerodynamics this does have more downforce than the standard gt4 the way porsche talks about it basically if you take all of the adjustments that you can make with the downforce whether that's up front with the diffuser or the rear wing you can maximize the downforce at basically the low downforce setting of the porsche gt3 and so their thinking is you know they want this to be more of you know a friendly approachable it's not as reliant on downforce it's still fun out on the road where you can't rely on downforce whereas the gt3 has more downforce making it a more capable track car at higher speeds up front you will notice two nacka ducks on the hood those are feeding air to cool the front brakes and if you go towards the back you will notice uh the swan neck uh supports for the rear wing and i asked abortion about this you know why do you change this basically if you have the supports underneath uh it influences the downforce a bit so they explained it as you know if you look at a plane the plane has the engines beneath the wing and that's for multiple reasons but part of that is the top of the wing is doing a lot of the lift and a wing on a car is that upside down right so the bottom of the wing is the important part so by supporting it from the top and having cleaner air flow beneath that wing where it kind of comes back together after it's past that swan neck support you have that laminar flow underneath the spoiler and that gives you better cleaner downforce so as far as some differences mechanically of this versus a 911 gt3 two of the things that the gt3 has that this does not the gt3 has rear wheel steering and the gt3 has a double wishbone rear suspension this is using the pearson struts front and rear and so the double wishbone gives you a bit more predictability at the limit with that gt3 and you also have the advantage of that rear wheel steering but as far as the overall you know what is this thing like to drive it's exceptional it's truly exceptional i mean i have a hard time finding faults uh the response is the biggest thing that i really appreciate about it in that you don't have to wait for things that you're asking for i mean when you're putting this in the the proper track modes and you're really going for it everything happens exactly when you want it to happen it's very predictable to drive i can get a little playful i was very impressed with the front end grip you know this was you can get those front tires overheated and start to get a bit of understeer but i found myself continuing to turn the wheel in more and it still had more and it would still turn in more and it was like wow like the front end grip is really good the ability of this thing to corner the handling is there and it's very responsive and that's what i like and that goes hand in hand with that throttle control that is so good and as a result you know you just feel so connected because of the responsiveness and it really is the same story with the brakes i mean the brakes feel really good as far as the steering the steering is light um there's no modes right there's one set setting porsche says we think this is good and that's what it is i like that about it uh it's light but it's also communicative and you know what's happening with your front tires you can kind of feel that lightness as you start to understeer you can feel it build as you go into the corner so the steering feels good to me though it is fairly light but if i had to come up with one downside it's not with this car but with every other cayman out there this vehicle proves that the cayman can use more aggressive gearing and it's using more aggressive gearing with a more powerful engine usually you get the opposite if you don't have much power you have to use really aggressive gearing so that you can you know get some decent acceleration this car does both things to make it faster shorter gears and more power so it shows that every other cayman can get away with significantly shorter gearing but they don't do it they don't give you that so that is my complaint let the other caymans have some fun as well the gearing in this is fantastic the engine in this is exceptional overall driving this thing on the track it's wonderful thank you all so much for watching if you have any questions or comments feel free to leave them below

Channel: Engineering Explained

Views: 434,393

Keywords: combustion engine, boxer engine, best combustion engine, best gas engine, porsche gt4, porsche gt4 rs, cayman gt4, cayman gt4 rs, porsche cayman, porsche gt3, porsche gt3 rs, engineering explained, car review

Id: 24cWC_siABI

Length: 15min 21sec (921 seconds)

Published: Fri Apr 01 2022