It’s official! The all new 2015 Corvette Z06 had its LT4 engine certified by SAE and the numbers are sure to leave any Corvette enthusiast smiling. At 650 horsepower and 650 lb-ft of torque, the Z06 will be the most powerful production car ever made by General Motors.
“The LT4 Small Block sets a new benchmark for power and torque at GM,” said Steve Kiefer, vice president, GM Powertrain Engineering. “The engine also puts the new Corvette Z06 on par with the most powerful supercars offered in America, while delivering performance with impeccable manners that make it suitable for daily driving.”
General Motors says their new engine for the Z06 produces 40 percent more peak torque (180 lb-ft) than the previous Z06’s 7.0L LS7 and 7.5 percent more than the supercharged 2013 Corvette ZR1’s 604 lb-ft of torque. The LT4’s 650 horsepower rating is 29 percent greater than the LS7’s 505 horsepower and 12 horsepower more than the ZR1’s LS9 engine.
“Torque is the pulling power of an engine and the LT4’s abundance of it at every rpm in the engine’s speed range helps the 2015 Corvette Z06 accelerate quicker and respond nearly instantaneously,” said Jordan Lee, chief engineer for Small Block engines. “It’s the very definition of power on demand.”
Here’s the official graph:
GM describes the LT4 as a “veritable fountain of low-end torque” as it produces 457 lb-ft just off idle and 625 lb-ft by only 2,800 rpm. The LT4 maintains 90 percent of peak torque, or 592 lb-ft, from 2,500 to 5,400 RPM.
“The new LT4 engine builds on the design strengths of our previous supercharged engine and leverages the technologies introduced on the Corvette Stingray – direct injection, cylinder deactivation and continuously variable valve timing – to take Corvette performance to an all-new plateau,” said Lee. “Our new, very compact supercharger also helps the engine make power more quickly, and perhaps more importantly, it helps produce more torque earlier in the rpm band.”
“It’s also worth mentioning that the LT4’s supercar performance numbers are achieved with an engine that is nearly the same size as the very compact LT1 engine introduced in the 2014 Corvette Stingray,” Lee said. “The power density of the LT4 makes it one of the smallest and lightest 650-hp engines in the industry.”
The new LT4 engine is based on the same Gen 5 small block foundation as the Corvette Stingray’s LT1 6.2L naturally aspirated engine, incorporating several unique features designed to support its higher output and the greater cylinder pressures created by forced induction, including:
- Rotocast A356T6 aluminum cylinder heads that are stronger and handle heat better than conventional aluminum heads
- Lightweight titanium intake valves
- Machined, forged powder metal steel connecting rods for reduced reciprocating mass
- High 10.0:1 compression ratio – for a forced-induction engine – enhances performance and efficiency and is enabled by direct injection
- Forged aluminum pistons with unique, stronger structure to ensure strength under high cylinder pressures
- Stainless steel exhaust manifolds and an aluminum balancer that are lighter than their LT1 counterparts
- Standard dry-sump oiling system with a dual-pressure-control oil pump.
The 1.7L Eaton supercharger is more compact than the one found on the LS9 and it spins at up to 20,000 RPMs – 5,000 more than the ZR1 too. The smaller rotors spin up faster which enables the boost earlier in the RPM band.
The MSRP of the Corvette Z06 has not been released, but the Corvette Team has previously said if you could afford a C6 Z06 then you can afford the C7 Z06. We think the car will start slightly north of $75,000. Considering that the ZR1’s MSRP started at $105,000 and the new Z06 will be more powerful for nearly $30,000 less is an amazing gift to Corvette buyers.
Click here to download the official press release PDF.