Back in August, we exclusively reported the upcoming mid-engine Chevrolet Corvette Z06 would feature a twin-turbo flat-plane-crank dual-overhead-cam V-8 based on the C8.R race car's engine. Now, we can report from an even higher-placed source that the range-topping C8 Corvette ZR1 will add a performance hybrid system to boost it to 900 hp.

Rumors of a hybridized C8 have been flowing for quite some time, but now we have exclusive confirmation from a senior official at GM. The ZR1 will build on the Z06's all-new engine with a performance- (not fuel economy-) oriented hybrid system to fill in torque gaps and increase total output to an even 900 hp.

See all 32 photos Our rendering of what a C8 Corvette Z06 could look like

Our source wouldn't elaborate on the engineering details, so we're still unclear whether street cars will share the C8.R's 5.5-liter displacement, which is unusually large for a flat-plane engine and would likely vibrate too much for customers' liking. Past rumors have suggested displacement ranging from 4.2 liters to 5.5 liters.

At a minimum, a hybrid system would sandwich an electric motor between the engine and transmission to bolster output. We've heard previously, though, the somewhat small frunk in the base C8 Stingray is protecting space for a pair of front-mounted electric motors which can both increase performance and, more critically, perform active torque vectoring to complement the rear axle's electronically controlled limited-slip differential. This first-of-a-kind all-wheel-drive ZR1 could see major benefits in handling and the ability to put down power while exiting corners. This is a strategy that's been employed to great effect on other hybrid supercars like the Porsche 918 Spyder.

See all 32 photos

Naturally, electric motors, a battery pack, inverters, and wiring will add substantial weight to the car, which is why it all needs to add enough power to balance things out. The big question is where Chevrolet will place the battery, which it will want to mount as low as possible to keep a low center of gravity. Other mid-engine hybrids mount it in the firewall between the engine and the seats. It's also possible it could be mounted in the bottom of the frunk or trunk, depending on how large it is. We expect it will be fairly small as it just needs to hold enough juice to boost the engine under hard acceleration. While some mid-engine hybrids have the ability to drive under pure electric power for short distances to meet emissions regulations in some countries and cities, we doubt this was a major concern for the Corvette team. Like the Ferrari LaFerrari, we think the ZR1 will be entirely concerned with performance, not efficiency.

Separately, our source corrected our previous speculation that the Z06, C8.R, and ZR1's DOHC engine would share design and engineering with the Cadillac 4.2-liter Blackwing V-8. Despite declarations from top GM and Cadillac brass the Blackwing is exclusive to Cadillac, we figured there would be some shared engineering resources to save money. That's not the case, our source says. Years ago, under a previous product plan that's since been whittled down, Cadillac was promised an exclusive engine and got it, so GM gave Cadillac and Chevrolet separate pots of money to design two different DOHC V-8s simultaneously.