Chevrolet Announces Certified Power Ratings for the New Chevrolet Corvette ZR1
PONTIAC, MI –When it was introduced at the North American International Auto Show in Detroit earlier this year,the 2009 Chevrolet Corvette ZR1’s power was estimated at 100 horsepower foreach of its 6.2 liters of displacement. GM Powertrain has completed SAEcertification of the ZR1’s supercharged LS9 V-8 and the results exceed theestimate: 638 horsepower (476 kW) and 604 lb.-ft. of torque (819 Nm).
The LS9’soutput is nearly 103 horses per liter, or just about 1.7 horses for each of theengine’s 376 cubic inches. It is the most powerful automotive production engineever manufactured by General Motors and enables the Corvette ZR1 to achieve atop speed of more than 200 mph (322 km/h).
“One ofthe most amazing things about the Corvette ZR1 is the level of refinement thatour designers and engineers have attained. Even with all that power, this carhas road manners that will allow our customers to enjoy it on the streets as adaily driver, and on the track,” said Chevrolet General Manager Ed Peper.
TheCorvette ZR1 goes on sale this summer. Its 638-hp supercharged engine iscomplemented in the chassis by heavy-duty components not offered in any othermodel, including a six-speed manual transmission with race-hardened gears anddual-disc clutch technology that delivers exceptional clamping power and lowerinertia, as well as strengthened axle components.
Fueleconomy testing has not been completed, but engineers are confident the ZR1will be the most fuel-efficient 600-plus-horsepower car on the market.
The LS9engine is hand-built by specially trained technicians at GM’s Performance Build Center in Wixom, Mich.
It is a unique, small-volume engine production facility that also builds theChevrolet Corvette Z06’s LS7 engine and other high-performance GM productionengines.
“Developingthe LS9 involved more than simply striving for a great horsepower number.Endurance and reliability testing have shown the engine to be robust andlow-maintenance, just like other engines in the small-block family,” said SamWinegarden, executive director, engine engineering for GM Powertrain. “That itis distinguished as the most powerful engine ever from General Motors is asource of immense pride among everyone involved with the LS9.”
The keyenabler of the LS9’s performance is the industry’s first production applicationof a new, positive-displacement Roots-type supercharger that has a uniquefour-lobe rotor design. Its design promotes quieter and more efficientperformance, while the large, 2.3L displacement ensures adequate air volume athigh rpm. Maximum boost pressure is 10.5 psi (0.72 bar). It is teamed with anintegrated charge cooling system that reduces inlet air temperature for maximumperformance.
“Thecombination of large displacement and the new, four-lobed rotor design broadensthe effective range of the supercharger, allowing the engine to make more powerat lower rpm and sustain it throughout the power band,” said Winegarden. “Thelow-end torque is tremendous and the high-rpm charge from the supercharger issimply amazing.”
A raisedhood provides adequate clearance for the LS9, while a polycarbonate window inthe hood provides a view of the engine beneath it.
The LS9features many unique design and manufacturing details that support itshigh-performance nature. They include:
- Aluminum cylinder block with iron cylinderliners that are finish-bored and honed with a deck plate installed.
- Forged steel crankshaft with a nine-bolt flange.
- Titanium connecting rods and forged aluminumpistons.
- Stronger, rotocast cylinder heads with 2.16-inch(55 mm) titanium intake valves and 1.59-inch (40.4 mm) hollow-stem,sodium-filled exhaust valves.
- Camshaft with 0.555-inch (14.1 mm) lift forexcellent idle and low-speed driving qualities.
- A dry-sump oiling system with 10.5-quart (9.9liters) capacity.
- Integrated oil cooler and piston-cooling oilsquirters.
- Intercooler cover visible through the hoodwindow that features ZR1-unique blue accents and “LS9 SUPERCHARGED” embossed onthe left and right sides.