Chevrolet Corvette C6 ZR1 

Production period:	2007 to 2013
Class :	sports car
Body versions :	Coupe , convertible
Engines:	Gasoline  : 6.2 liters (476 kW)
Length:	4435-4459 mm
Width:	1844-1927 mm
Height:	1246 mm
Wheelbase :	2686 mm

The Chevrolet Corvette C6 ZR1 is built on the sixth edition of the US sports car Corvette produced by General Motors ,In December 2007, General Motors presented the new edition of the Corvette ZR-1 from that previously built in 1989.

History

This is the current top model of the Corvette based on the C6. The new Corvette ZR1 now has a maximum output of 476 kW (647 hp) and a maximum torque of 823 Nm. The sports car was the strongest, fastest and most powerful Corvette ever built by GM.

In the development of the ZR1 the competition model, the Dodge Viper played no unimportant role. As in 2007, the new Dodge Viper with 441 kW (600 hp) appeared, the former Corvette top model, the Z06 with 376 kW (512 hp) could not stop it. "Who likes to finish second?" Corvette spokesman Dee Allen asked shortly after the premiere of the new Viper, fueling the hope that General Motors would not let this shame sit on its shoulders for long. When CEO Rick Wagoner announced that it was "very important" for him "to have the strongest, most powerful and best-handling sports cars in the United States", it was clear that a new model would be added.

Exactly one year later, the Corvette ZR1 was unveiled at the Detroit Motor Show. "With the ZR1 we want to show what an American supercar can do. That at a price that makes European sports cars look old. They are twice, three times or four times as expensive, "says Chevrolet boss Ed Peper, who is also responsible for the Corvette.

Bodywork 

The new Corvette ZR1 differs by several features from the normal C6. The car is even lower on the road, has a larger radiator, thus a larger cooling air opening, a large hood on the hood and deeper gills in the flank, also a ZR1-specific front spoiler and a special rear spoiler in full width with raised exterior elements.

For the body is - Corvette typical - glass fiber reinforced plastic (GRP) used. However, carbon fiber reinforced plastic (CFRP) is used for the redesigned front fenders, the roof, the bonnet and the front and rear spoilers . A special feature of the ZR1 is a window in the CFRP bonnet, which reveals the view of the engine / intercooler . For reasons of rigidity, as with the Z06, no Targa roof is offered.

Due to the use of carbon fibers in the body, the empty weight is only 1453 kg. With 2.25 kg / hp, the strongest Corvette has a lower power to weight ratio than a Lamborghini Murcielago , a Ferrari F430 or a Porsche 911 GT2 , but a lower power to weight ratio than a Porsche 911 GT2 RS (power about 2.21 kg / hp).

Engine 

The LS9 engine (6.2-liter all-aluminum V8 with supercharged and integrated intercooler ) of the ZR1 is also a new development, delivering 476 kW (647 hp) at 6500 rpm and achieving a maximum torque of 823 Nm at 3800 rpm , The engine of the new ZR1 is a "small block" according to GM diction and is based on the LS3 engine of the Corvette C6 6.2 with 6.2 liters and not on the LS7 engine of the Z06 with 7.0 liters displacement.

The engine is a modified LS3 engine from the C6 with 6.2 liters and eight cylinders. Titanium valves and forged pistons found in the ZR1 version collection, just as one Eaton - Roots - compressor , the bar provides boost pressure for a maximum of 0.72. The LS9's "R2300" compressor is Eaton's sixth generation, with a special housing and new rotors that mesh four teeth, making them quieter and more efficient, while the large 2.3-liter Roots pistons provide the necessary air volume ensure high speed. A liquid-air charge air cooling system lowers the temperature of the charge air by up to 60 degrees Celsius.

The compression of the engine was reduced to 9.0: 1 due to supercharging. The upper speed limit of the ZR1 engine is 6600 / min. The LS9 was exclusively hand-assembled at GM's Performance Build Center, an exclusive small-unit engine manufacturing facility in Wixom . Here, the LS7 engine of the Corvette C6 Z06 and other high-performance engines for GM production vehicles were also built.

To achieve a lower center of gravity, the LS9 engine of the ZR1 is installed even lower than in the Z06. The power is transmitted by a manually connected six-speed transmission, whose first gear reaches over 100 km / h. The new 2-disc clutch and 6-speed gearbox, drive shafts and chassis have been adapted to the higher engine or performance.

Internally, the LS9 engine of the ZR1 is also called "Blue Devil". The name comes from the name of the university's basketball team on which GM's CEO Rick Wagoner has studied; the " Duke University - Blue Devils " .

The LS9 engine of the ZR1 offers a high torque even at low speeds, then a straight-line torque curve and thus a continuous power development up to the maximum speed of 6600 / min. Test runs of "GM Powertrain" showed that the engine already achieves an output of 224 kW (304 hp) at 3000 rpm and a torque of almost 434 Nm at just 1000 rpm . The peak torque values ​​are around 4000 rpm, while the maximum power is reached at 6500 rpm. The engine constantly produces over 90 percent of its torque in the range of 2600 to 6000 / min. 

Transmission 

The Corvette ZR1 is equipped with a "Tremec TR6060" six-speed manual transmission and a special two-disc clutch system. The gearbox has been redesigned to deliver more than 800 Nm of torque to the LS9 engine, providing improved shifting characteristics. The two-disc clutch system has clutch discs with a relatively large diameter of 260 millimeters, to distribute the high torque of the engine in this way over a larger area.

The maximum speed of the ZR1 is reached in sixth gear; This means that the sixth gear can also be used as a "real drive". In contrast, in the normal Corvette C6 and the Z06 the maximum speed is reached in fifth gear - the last gear is used in the so-called overdrive as Schon- or Spargang.

Suspension

The spaceframe aluminum chassis of the ZR1 and the spring-damper combination of the suspension is adopted by the weaker sister model Z06 and amplified accordingly. The adjustable and electronic damper system got a special racing mode. It is a so-called magnetic-selective-ride control with track-level suspension . The damper map of the suspension can be selected in two stages, called "Tour" and "Sport". Already in the "Tour" mode, the Magnetic Ride System springs very tight. Still, the ZR1 is a bit more comfortable than the Z06 because it has softer springs. Only the stabilizers of the ZR1 are stronger than those of the Z06.

For the first time in the Corvette is also a standard brake system with perforated discs made of carbon-ceramic ( carbon fiber reinforced silicon carbide ), installed for better cooling of the system and larger calipers with increased surface area. At the front, six-piston fixed calipers act on 394 mm (15.5-inch) brake discs, behind four-piston fixed calipers on 380-mm discs. Also new is the anti-lock braking system (ABS) and Electronic Stability Program (ESP) from Bosch. The ESP is three-stage and can be switched off. The chassis thus allows lateral acceleration of significantly more than 1 g  - without semislicks, The Michelin tires of the ZR1 are specially made for this model.

Performance

The top speed is electronically limited to 330 km / h in terms of tire durability. The speedometer is therefore "only" up to 330 km / h. The acceleration from 0 to 100 km / h is achieved in 3.4 s, from 0 to 200 km / h in 10.3 s and from 0 to 300 km / h in 32.5 s. The small course in Hockenheim is circumnavigated in 1: 08.3 minutes.

In July 2008, GM development engineer Jim Mero rounded the Nordschleife of the Nürburgring in a record time of 7: 26.4 minutes. In the summer of 2011, Jim Mero was able to improve this time to 7: 19.63 with a 2012 ZR1. This ZR1 reached behind the Porsche 911 GT2 RS, the second fastest driven lap time of a production car at the Nürburgring. This makes it the fastest and most powerful vehicle General Motors has ever produced in its more than 100-year history.