How the 2009 Chevrolet Corvette ZR1 Works

The development of the ZR1 started when General Motors CEO Rick Wagoner looked at the $60,000 Corvette Z06 and wondered what the Corvette team could develop if it was shooting for a $100,000 'Vette. The result was a secret GM project labeled "Blue Devil" (after Wagoner's college mascot at Duke University) that took four years to become the most expensive Chevrolet ever built.

Along the way, the development team tested the bounds of automotive technology. An experiment with a turbocharged engine showed promise -- until the test car burned to the ground at GM's test track. Still, the team pushed on and created a car that is expected to appeal to the kind of buyers who normally shop at high-end Italian car dealerships. Corvette Vehicle Line Executive Tom Wallace got more specific, telling Motor Trend magazine that he expected the ZR1 to compete with the Ferrari 599, Lamborghini Murciélago and "any Porsche" [source: Motor Trend]. Keep reading to learn what the ZR1 has that allows it to compete with the best cars in the world.

Supercharger

What puts the ZR1 on the same playing field as other supercars is the engine's power. When the turbocharging experiments failed, the Corvette team turned to supercharging. A supercharger, also called a blower, is a device that shoots compressed air into an engine by forcing it through rotating chambers. The more air an engine has, the more power it creates. A belt on the engine turns the supercharger, allowing it to suck outside air into the engine. The ZR1 uses a Roots-type supercharger, which has four lobes that lock together like gears. Most superchargers have only three lobes. The lobes on the ZR1's supercharger also rotate 160 degrees -- lobes in most superchargers rotate only 60 degrees. The four-lobe design and extra rotation increases thermal efficiency and has nearly the same power efficiency as a turbocharger. With every rotation, the ZR1's blower forces 2.3 liters of pressurized air into the engine. To avoid the massive bulge on the hood that's usually associated with superchargers, the ZR1's blower is mounted low in the V of the V8 engine and uses side-mounted intercoolers and heat exchangers.

Though the supercharger on the ZR1 is one of its standout characteristics, its LS9 engine is no slouch, either. The engine shares its basic 6.2-liter design with other Corvettes but features some extra high-end materials and parts that are lighter and stronger than conventional engine parts -- like a forged steel crankshaft, steel main bearing caps, titanium connecting rods, forged aluminum pistons and roto-cast cylinder heads that have a more consistent density than other heads. There's more titanium on the intake valves (to save weight without losing strength), and the stems on the exhaust valves are hollow. Even the engine's flywheel has been modified for supercar duty. The flywheel on base and Z06 Corvettes is attached to the crankshaft with six screws, while the ZR1's is attached with nine.

Transmission

Sending the engine's power to the wheels is a six-speed Tremec TR6060 transmission with a close-ratio gear set. On the ZR1, the gearing is 16 percent longer than that of the Corvette Z06, which means the ZR1 can get to over 60 mph without leaving first gear. For higher gears, the spread on the ZR1 is 26 percent shorter than the Z06. Though this makes for a lower redline in fifth and sixth, it also means the ZR1 easily scoots to over 200 mph. To further handle the engine's torque output, the gear, shaft gear and shaft materials were strengthened, and a twin-plate clutch was used to improve shift feel.

The ZR1's chassis is similar to the Corvette Z06. It uses the same aluminum structure but has some carbon fiber components to offset the engine's extra weight (hey, superchargers can be heavy). The ZR1 also has GM's Magnetic Selective Ride Control System, which allows drivers to select the type of suspension responses they prefer. On the ZR1, the system uses Magneto-Rheologial shocks, which adjust automatically based on driving conditions for optimal ride and control. The ZR1 also has stiffened and larger anti-roll bars. All together, the suspension system is designed to make the ZR1 a comfortable road car that can provide blistering track times.

Of course, a car like the ZR1 needs maximum stopping power. Its front brakes are 15.5-inch carbon-ceramic rotors, and the back rotors are 15 inches. Both are radially and laterally vented discs (to avoid too much heat) and were originally designed for the Ferrari FXX and Enzo. The calipers are Brembo monoblocs with six pistons in front and four in the back.

Connecting the ZR1 to the road are larger tires than on other Corvettes. The ZR1 has Custom Michelin Pilot Sport 2 run-flat tires on the front. They sit on 10-inch, one-piece 20-spoke rims from Speedline and measure 285/30R-19. In the rear, the tires measure 335/25R-20 and sit on 12-inch Speedlines.

The ZR1 takes most of its styling cues from the rest of the C6 line, but to reduce weight, GM used a number of carbon-fiber panels. The fenders, hood, chin-spoiler, rocker panels and roof are all made of the lightweight but strong material, and some of the pieces have been left unpainted, so you can actually see the carbon fiber, which is an industry first. Usually, carbon-fiber yellows and cracks when exposed to ultraviolet light, but Chevrolet uses a special coating (that reportedly costs $60,000 a gallon) to protect the carbon-fiber on the ZR1.

The ZR1 also has a few specialized exterior flourishes. The more powerful braking system requires front and back brake vents that are larger than on other Corvettes. The brake vents aren't all about utility, though: The front vents feature horizontal gills, in an homage to the 1963 Corvette. The ZR1's hood also has a slight bulge in it (to contain the engine), which features a window that looks down on the engine. An air intake at the front of the hood helps bring air into the engine, and a larger chin spoiler helps the ZR1's nose stay planted. A full-width spoiler does the same for the rear.

For a $100,000 car, the ZR1's interior can be surprisingly basic. That's because Chevrolet wanted to appeal to buyers looking for a stripped-down track car, as well as those looking for luxury. While the interior design isn't changed much from a base Corvette's, the ZR1 has a boost gauge and ZR1 logos on the headrests and tachometers. A leather-wrapped interior is available.

With all of that hardware, it's not surprising that the ZR1 can produce some truly amazing numbers.

Of course, there are some downsides to the ZR1's performance -- not that anyone with $100,000 to spend on a car will notice. The ZR1 is the first Corvette to be subject to the gas-guzzler tax, even though the EPA hasn't released its estimated fuel economy for the car. Car and Driver magazine estimates to fuel economy to be 14 mpg in city driving and 23 mpg on the highway [source: Car and Driver]. Premium fuel is required, but that's a small price to pay for premium performance.

General Motors is hoping to position the ZR1 as a bargain alternative to other supercars. The ZR1 should compete with the Porsche 911 GT2, Ferrari 599 GTB and the Lamborghini Murciélago. While no head-to-head comparisons have been done, the ZR1 appears to be an able challenger.

On paper, it looks like GM's bet may pay off: The ZR1 can hold its own, at about half the price of other supercars.

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