Screw the C8 Corvette Stingray - You Want the C8 Corvette Z06
It will be the first turbocharged Corvette!by Ciprian Florea, on
Now that the 2020 Chevrolet C8 Corvette has been unveiled and is on its way to dealerships, everyone is wondering what the new-generation Z06 will bring to the table. Original rumors talked about a turbocharged 5.5-liter V-8, but it seems that Chevy will actually go with a different design. The new mill will be twin-turbocharged, a first for the nameplate, but it will be closely related to the engine in the race-spec Corvette C8.R and loosely based on a Cadillac unit. Let’s find out more about that below.
Sources Say the C8 Corvette Z06 Will Have a Flat-Plane-Crank, Twin-Turbo, V-8
Chevrolet is actually working on a brand-new unit for the C8 Corvette Z06
While the old rumors that Chevy will use a twin-turbo version of the 5.5-liter V-8 in the C7.R made some sense, it turns out that Chevrolet is actually working on a brand-new unit for the C8 Corvette Z06. What’s more, it will be a flat-plane crank engine instead of Chevy’s traditional pushrod design. It will also have a dual-overhead-cam, another significant departure from previous Corvette V-8 engines. That’s the word from Motor Trend, which quotes a "deep source" from the "Corvette team" working on both the C8.R and the C8 Corvette Z06.
The insider information can be confirmed by footage of the C8.R spotted testing at Sebring. Specifically, the exhaust note is entirely different from the C7.R and more consistent with a flat-plane-crank design. The higher-pitches exhaust note, the higher rpm, and the longer times between upshifts are all typical of the flat-plane crank design; as are the quicker downshifts during which the unit spins up to high rpm faster than a pushrod.
The Same DOHC Twin-Turbo V-8 is Being Used in the Corvette C8.R Race CarQ
Chevy can't afford to make mistakes here, so it's adopting a flat-plane crank design strictly for the sake of performance
But why is Chevy using a flat-plane crank V-8 instead of the more traditional pushrod design? Well, the fact that it will be shared with the C8.R is the best explanation. You see, the C6.R and C7.R were very successful on the race track, so the C8.R has a big pair of shoes to fill. Chevy can’t afford to make mistakes here, so it’s adopting a flat-plane crank design strictly for the sake of performance. And if this works in a race car, it’s not a bad idea to transfer it to a road car, right?
Flat-plane crank engines come with many advantages, especially for mid-engined cars. The smaller, lighter crankshafts can spin up faster and lose less power to rotational inertia than cross-plane-crank engines. The different firing order also enables better exhaust scavenging, which improves performance and combustion efficiency. Granted, the flat-plane-crank design isn’t as balanced as the cross-plane unit due to stronger vibrations at higher rpm, but this is where the dual-overhead cams come in to help the engine spin beyond 7,000 rpm without damaging other internals.
The Twin-Turbo V-8 in the Corvette Z06 Will Be Derived From Cadillac’s Blackwing V-8, But It Won’t be the Same!
Currently used in the CT6-V sedan only, the mill cranks out a solid 550 horsepower and 627 pound-feet of torque
So, is Chevy actually spending time and money to develop a brand-new engine? Hell no, that would be crazy, and GM wouldn’t risk it. Luckily, GM already has a base for this flat-plane-crank engine: Cadillac’s Blackwing mill. A twin-turbo, 4.2-liter V-8, this mill is also known as the GM RPO LTA and features a dual-overhead-cam, just like the upcoming Corvette Z06. It’s Cadillac’s first-ever twin-turbo V-8 ad the first Cadillac-exclusive dual-overhead-cam V-8 since the Northstar engine was dropped in 2011.
Currently used in the CT6-V sedan only, the mill cranks out a solid 550 horsepower and 627 pound-feet of torque. The engine is described as exclusive to the Cadillac brand, and Chevrolet claims that it hadn’t even tested it in the C8 Corvette, but this doesn’t mean that it won’t have access to it. Although Cadillac has made it pretty clear that Chevy won’t get the Blackwing engine, the Blackwing’s block will be used as a base for the Z06’s twin-turbo mill.
Because the Blackwing is a cross-plane-crank and hot-vee design, Chevy wouldn’t be able to drop it under the C8 Corvette’s hood anyway. But GM will rebuild the engine around the same block, and it will probably use similar heads. But the bore will change as well, as the Blackwing’s current design is good for reliability and torque, but not so much for high rpm performance. This means that the Blackwing’s displacement will increase for the C8 Z06. We don’t know by how much yet, but don’t expect it to jump to 5.5 liters. Since larger displacement means bigger vibrations, Chevy will keep things smaller, probably around the 4.5-liter mark.
|Cadillac CT6-V Blackwing V-8|
|Suspension||Magnetic Ride Control|
|Brakes||Brembo V-Series Specific|
|0-60 mph||3.5 Seconds (est)|
|Top Speed||192 mph (est)|
C8 Corvette Z06 vs. C8 Corvette Stingray - The Differences
It's safe to assume that the upcoming C8 Z06 will arrive with almost 700 horsepower, if not a bit more
The C8 Stingray and the C8 Z06 will share many components, but they will also have significantly different parts. The Z06 will stand out in three key areas.
First, it will have a more aerodynamic body. While the C8 Corvette comes with an optional rear spoiler, the Z06 will be offered with a larger wing. It won’t be as extreme as the C8.R, but it will generate a lot of extra downforce. Chevy will also add a bigger splitter in the front and will enlarge almost all outlets in the front bumper and the rear fenders. Second, the Z06 will ride on a bespoke suspension system derived from racing. Specifics aren’t yet available, but the Z06 will be the most track-oriented C8 Corvette after the race-only C8.R.
Third, and likely the most important, the Z06 will have a turbocharged and much more powerful engine.
Turbos are a first for the Vette, a nameplate offered with naturally aspirated and supercharged mills only until 2019. The use of turbos will keep the engine smaller. While the C8 Stingray features a 6.2-liter mill, the Z60 will have a V-8 that will displace less than 5.0 liters. Naturally, the Z06 will be the more powerful car. The C8 Stingray comes with up to 495 horsepower and 470 pound-feet of torque on tap, but the Z06 will have in excess of 600 horsepower. While Cadillac’s Blackwing generates 550 horses, Chevy’s version will have to surpass the old C7 Z06. The latter came with 650 horsepower on tap, so it’s safe to assume that the upcoming C8 Z06 will arrive with almost 700 horsepower, if not a bit more.
If these rumors prove to be correct, the C8-generation Z06 will be a major departure from its predecessor. Not only the first Corvette to feature a turbocharged engine, but it will also be the most powerful Z06 yet. And if Chevy goes wild on the output, it could be more powerful than the C7-generation ZR1 as well. If things go well, the Stingray will remain the only naturally aspirated Corvette in production, and this might change in a couple of years. Just like the 911, the Corvette might go full-time turbo in the near feature. Sure, it’s a bit disappointing after all these decades, but hey, turbocharging comes with many advantages in the performance and fuel economy departments.
Read our full review on the 2020 Chevrolet C8 Corvette Stingray.
Read our speculative review of the 2020 Chevrolet Corvette Zora ZR1
Read our full review on the 2015 Chevrolet Corvette Z06.
Source: Motor Trend