Corvette ZR1 Delivers The Goods With Supercharged Engine

No doubt vexed by the power of the new Dodge Viper SRT-10, GM has upped the anti with the launch of the 647 bhp Corvette ZR1. Not the latest Corvettes are lacking, as they have made quite a mark in endurance racing over the past couple of years with the 7-liter Corvette Z06.

Instead of getting more power out of that big engine, GM has opted for a new version of the 6.0 liter job, now enlarged to 6.2 liters. Not only that, but this new engine is supercharged to increase power throughout the range, producing 140 bhp more than the Corvette Z06 7.0 liter unit. When the new engine was announced, GM estimated the power output at 620 bhp, but the power has been certified as 647 bhp or 104 bhp per liter! Pretty awesome.

What GM calls the all-new LS9 V-8 engine, is in fact just the latest version of the small block design, with aluminum block and heads. It is still an old-fashioned pushrod-ohv unit, though. In naturally aspirated form it develops 

430 bhp at 5,900 rpm, but with the supercharger power is up to 647 bhp and torque of 600 lb ft (819 Nm). The torque is also much more that from the 7.0 liter mill by 25 per cent so this engine will have masses of power at almost any speed.

This is enough power to take the new Corvette to 60 mph in under 4 seconds, and to give a top speed of 200 mph.

Eaton four-lobe blower gives the power

The hand-built engine gets its power from a new Eaton Roots type supercharger with four lobes instead of three, which is said to improve response up to the red line of 6,600 rpm. It has an inter cooler to improve performance, and gives a big increase of power throughout the range.

The engine is coupled through a twin-plate clutch to an up-rated six-speed manual box, and the torque tube and drive-shafts have been beefed up. The twin-plate clutch combines low pedal effort and less inertia, meaning quicker shifts, and less wear on the synchromesh.

To improve handling, the suspension has been tweaked and lowered, and magnetic damping is standard. As a result, tests show that the ZR1 can corner at over 1.0 g, which used to be the hallmark of real racers.

Carbon-ceramic disc brakes

Weight is reduced by carbon-ceramic, drilled disc brakes 15.5-inch diameter (394 mm) at the front and 15-inch diameter (380 mm) at the rear. Six-piston front calipers and four-piston rear calipers are used. Of course, these improve braking performance especially from high speeds, and are now found on most 200 mph supercars.

Michelin has developed some Pilot Sport 2 tires specifically for the ZR1 - P285/30ZR19 at the front and P335/25ZR20 at the rear.

To make the car look different, it has a transparent window in the carbon fiber hood, a carbon fiber roof panel and cross member and front apron. Of course, these panels reduce weight a tad, too.

What about the weight? Pretty cool, this Corvette ZR1 weighs just 3,350 pounds (1,519 kg) , a good deal less than the Aston Martin V12 Vantage RS concept, which is fairly light. So, the ZR1, with a power-to-weight ratio of 405 bhp per tonne, will be a stunning performer.