5 Genuinely Impressive "Flaws" Of The C8 Corvette

hello everyone and welcome as you can see I am sitting inside of a cutaway of a c8 Corvette while also sitting next to a functional c8 Corvette in this video we're going to be discussing five aspects of the new Corvette that at face value you might be disappointed to hear the fact that it's break by wire that it's stopping distance is worse than the c7 Corvette that it understeers that it uses a pushrod engine and finally that it comes with all season tires and you're thinking what none of this is any good but if you look closely at any one of these aspects you'll find there's actually a brilliant reason as to why so for number one we're gonna start off with one of my favorite facts about this new Corvette so when I was chatting with the Chevy engineers about this one of the fascinating things about their break by wire system is that it can bring the car to a stop even if the brake fluid boils what Chevy calls this eBoost now before you panic about the electronics failing and you're not having any brakes don't worry Chevy thought about this too if the electronics were to fail the master cylinder still builds pressure from your foot and you can stop the car but usually it's just using your foots travel to determine how much pressure the electric pump should generate for the brake pads this means you can actually create different brake modes altering how the brake pedal feels if you'd like and Chevy does this depending on what drive mode you're in what's more fascinating to me is what happens when things start to get hot so let's say you brake really hard and then you accelerate up to 120 miles per hour and then you brake really hard again and then you accelerate again and then you brake really hard again and again and again and again we start to really heat up that brake fluid and you know perhaps you haven't been keeping up with your maintenance and a little bit of water has ingested into that brake fluid well as that brake fluid gets really hot you could start to boil that fluid well once that fluid turns into a gas gas is compressible which is why boiling brake fluid is so dangerous if you have air in your brake lines it's very difficult to stop because instead of applying pressure to the brake pads you're just slightly compressing some of the air in side the lines and you're not getting much brake force your foot can only press the brake pedal down all the way once you've floored the brakes if it ain't stopping you're not stopping scary stuff but what if you have an electric pump creating that pressure when you floor the brake pedal and the fluid has boiled the pump doesn't have a hard stop like your foot does with the floor it just sees that you want high braking pressure and because there's air in the line you're not getting it so it pumps and pumps and pumps compressing that air as much as possible so you actually build up enough air pressure within the line to force that pad against the rotor and stop the car incredible number two is stopping distance now the previous generation in Corvette the c7 had one of the shortest stopping distances of any production car out there so Motor Trend tested a 2014 Corvette Convertible and that stopped from 60 miles per hour down to zero in just 90 feet well Motor Trend tested the new Corvette the 2020 c8 and it stopped from 60 miles per hour down to zero in 97 feet 7 feet longer so why did this happen well I asked Corvette engineers about this and there are a couple of reasons for it first off it should be noted that from a physics standpoint there's nothing about the c8 that indicates it should have a longer stopping distance because it has the engine in the rear and has a rear focused weight distribution under braking as that weight shifts forward it has the weight more evenly distributed amongst the four tires versus the previous generation Corvette which is beneficial for braking but this also brings up the first challenge unlike the previous generation Corvette which had a 50/50 weight distribution this has a 60/40 weight distribution so when you slam on those brakes the weight distribution shifts from the rear to the front and a loading shifts where the majority of the load is on those front tires so that means you're switching from a rear brake bias to a front brake bias and Chevy says that managing that from an ABS standpoint is challenging but once that transition occurs ABS is easy to manage now once you've started breaking from then on out it should have a better distribution and better tires and so it should still have a better stopping distance right well here's the thing if you want to design a car that stops as quickly as possible that's very different from designing a car that goes around a track as quickly as possible so what Chevy claims they did is that they limited the maximum braking force on the rear tires because if the rear tires are overloaded stopping as fast as they possibly can then any provided steering input from the front of the car makes the rear end very twitchy the back wants to kick out obviously this isn't ideal if you're trying to go around a track as quickly as possible so in order to improve the track friendly nature of the c8 Corvette the rear brakes are just slightly limited meaning stopping distance is also slightly limited number three if you've watched any video of the new Corvette driving on a track you've probably heard the reviewer state that the car understeers it's a go to talking point and I do think it's fine to make that claim I drove one on a track and I found understeer to be minimal but there was a touch of it I think the danger here is simply stating it understeers that's bad and then not diving in any further because you can design a car to do anything increase the size of the rear roll bar it oversteers decrease the front tire pressure it may oversteer take out the front sway bar understeer gone changing the alignment tire pressures roll bars and so on all of this changes which end of the car is more likely to lose traction first whether it's the front end understeer or the rear end oversteer but when you're creating an insanely capable car and you're offering it at a pretty reasonable price tag for what you're getting this one here is at about 72,000 as it sits well it's a recipe for inexperienced drivers to get themselves into a bit of trouble you have to know your audience and understeer is safer and easier to predict if you're not exactly certain what you're doing behind the wheel but that doesn't mean the driving experience has to be dull Chevy has a few clever tricks to make this thing even quicker on a track one that's very cool is the ability to corner balance the car meaning the combined weight of the rear left and front right tire matches the combined weight of the front left and rear right tire which aids in hand Chevy has put threaded spring seats so you can adjust the preload of the springs and alter the height for corner balancing with 20 millimeters of travel up or down from the standard position for track use they also recommend dropping your cold tire pressure from about 30 psi all around 223 psi in the front 24 psi in the back obviously driving on a track you're going to put a lot more heat into the tires which raises their hot tire pressure significantly so they're targeting a hot tire pressure of about 32 psi they also recommend adjusting camber if you're gonna see some track use so the car is set at negative 0.5 degrees up front and in the rear for camber and they recommend for track use setting the front to negative 3 degrees and the rear to negative two point five degrees all of this is to say does it understeer yeah a little but the suspension has adjustability built in if you want to change that number four we're talking about engines now I used to say that push rod to valve per cylinder engines had no place in a modern car because I used to be dumb some things never change but push rod engines aren't dumb they're brilliant they're simple they have fewer moving parts than many alternatives they make great low-end torque they're compact they have an admirable engine weight and you know if you keep things simple you can keep costs down as well interesting to note now that they've stuck the engine in the back they don't have to worry about the intake manifold disrupting the drivers sight line so the intake manifold is now larger and for the first time on a Corvette it uses equal length runners the exhaust manifold also sweeps up now instead of down all of this helps to increase power to 495 horsepower and 475 feet of torque with the performance exhaust from the 6.2 liter v8 engine and for the first time the base stingray gets a dry sump oil system with three scavenge punks improving oil circulation for better track performance also a quick shout-out to Mobil 1 they've been a great partner to the channel in fact when I quit my engineering job back in 2014 it was a result of Mobil 1 inviting me to drive the all-new c7 Corvette on a track after well I had run out of vacation time a two-week notice fixed that and I spent my first time driving on a track in the c7 Corvette I even got a little trophy out of it for posting one of the quickest section times fun fact all c7 and c8 Corvettes are factory filled with Mobil 1 motor oil and they've been recommended service Vil for all Corvettes since 1993 in the case of the c8 it's using Mobil 1 ESP formula zero W 40 finally we get two tires one of my favorite subjects and this car is sitting on all season tires what a mid-engine car with its site set to supercar territory and it comes standard with all seasons I was just as disappointed as you are when I sat inside of one for the first time and then I drove it I don't know what magic Michelin has worked with these but you forget they have the words all season typed out on them on your first launch or your first hard corner these are very grippy tires they have nearly 1 G of cornering grip I measured a zero to 60 time up 3.4 seconds up to 40 miles per hour it's averaging 0.9 G's of acceleration and remember that's a rear-wheel drive car on all seasons stopping from 60 to zero happened in 112 feet meaning 1.07 average G's of deceleration on a rough road as a quick comparison I've taken my Mazda mx-5 on that same road and done the same braking test and it's sitting on Bridgestone re 71 our tires which are a very aggressive summer tire they have a short tread life and these tires stop my car in a hundred eleven feet just one foot shorter than these all seasons on the Corvette so their summer performance is excellent and yet they're still all season tires what I was also shocked to hear is that they're apparently rather decent in the snow now when I look at them I certainly have a hard time saying hey you should use these in the snow that's not what I'm saying I certainly think you should get the right tire for whatever situation you're in but I am saying that Corvette engineers drove these through Michigan winters and they were genuinely impressed with the grip these have in the cold and in the snow and there's one more trick engineers claimed about these tires apparently they're a little bit less sensitive to vertical loading versus the summer tires that are offered with the z51 package so what this means is say for example you're in the car and you're going over a crested corner well that's gonna change and pull off some of the loading on these tires and apparently in these situations this tire behaves a bit more predictably first I thought this might be a result of using softer side walls but the all-seasons have a very similar sidewall to the ps4 s tires offered with the z51 the difference is the all-season compound is softer and since the tread blocks have cuts in them they're also softer and this in a sense means the rubber behaves similar to using a softer spring which in scenarios like going over a crest means it feels more predictable even if the ps4s has more grip overall so hopefully one of the main takeaways that I'm trying to convey with this video is becoming clear and that's you know you don't have to have this quick decision immediately when you hear well something understeer something has all season tires some Break by wire that doesn't necessarily immediately mean it's bad and there's often very good reasons for why things are done and so if you dive a little bit deeper you can start to figure these things out and that's what I think is really cool about many of the aspects of this c8 Corvette and also I have to give a huge thank you to Chevrolet because I asked them I I saw this Corvette cutaway and I send them an email and I said hey can we put that thing in my garage and they were like yeah so I think that's incredible I'm stoked to have it here thank you all so much for watching if you have any questions or comments of course feel free to leave them below

Channel: Engineering Explained

Views: 1,081,239

Rating: 4.9084535 out of 5

Keywords: corvette, c8 corvette, 2020 corvette, 2020 chevy corvette, corvette stingray, corvette z51, corvette z06, chevy corvette, 2021 chevy corvette, mid-engine corvette, engineering explained, corvette engineering, v8 engine, corvette v8

Id: a2MxuknropY

Length: 12min 49sec (769 seconds)

Published: Wed Jul 15 2020

Reddit Comments

[u/dat_distraction]

I'd wager the extreme track alignment is necessary due to the intentionally soft ride quality. I've heard a lot of comments about how well the C8 rides on the street. This is partially the dampers, but is also directly attributed to soft(er) springs. Increasing spring rate is going to make the car more harsh no matter the shock trickery.

Watching some autocross footage, the car does have a lot of controlled body roll. In some corners it's just barely picking up the inside rear tire. For a car this large and long, that's impressive. With this much roll, your suspension is going through a large portion of it's range. I'd wager it doesn't have a ton of camber gain, so you compensate for that by running a ton of static camber.

In the past corvette generations, GM has notoriously had VERY conservative street alignment specs. Usually no more than 1* negative. Most autocross guys are running 2* on the front if not more and usually whatever the max rear camber they can get. The rear of the C5/6 can't usually get more than 1.5* negative without offset bushings. The C7 was a little better. I'm amazed you can get 2.5* from the factory setup.

Honestly, it'd be a neat aftermarket product idea if you could manage to create a "quick and easy" method of flipping between the alignment specs. You can easily mark a camber bolt for the 2 different alignments, but tie rods are difficult to consistently adjust.

[u/pm-me-ur-car-pic]

A set of all seasons are going to compare well to a set of track tires that aren't warmed up. High performance summer tires or track tires need to warm up a bit before they reach peak grip. I get the point he's making and those are some very grippy all-seasons, but that wasn't entirely fair. (That's putting aside that the braking test used two different cars, but obviously he doesn't have access to multiple sets of tires on the same car right now so that point is moot.)

He sort of hinted at the ability of the all seasons to handle crests and such on track but I seriously doubt they could hold up for a track session. Would just overheat and totally loose grip at best or get horribly scrubbed and completely shredded at worst.

In my mind the best benefit of the all seasons over the summers is tire life. A low profile set of summer tires, even on a luxury car that's driven as such, usually doesn't last that long. The only tires I can get for the 20s on my s class are performance summer runflats and they don't even make it to 15k miles. People who use their vettes like a GT instead of a sports car will appreciate the extra longevity.

[u/TaskForceCausality]

All season tires and understeer aren’t the stuff of gearhead dreams- but most car buyers aren’t gearheads. As YouTube capably shows, most people with performance cars have no idea how to drive them well.

If Chevy set up the C8 with sticky summer tires and aggressive neutral handling, they’d be class action sued by every boomer who wrecked their Corvette. Understeer and conservative tires keeps Mr Greyhair out of the ditch, and those of us with the training to get more out of the car know what to change.