- Dec 19, 2007
Detroit 2008: The King is back atop the hill - 2009 Corvette ZR1
Click the ZR1 for a high-res photo gallery of the new King of the Hill
The King of the Hill has returned! The new Corvette that has been variously known as the "Blue Devil" and SS for at least the past five years has now been officially designated as the ZR1. The new monster from Bowling Green has revived the ZR1 designation for the first time since the C4-based original faded away in 1995. Stories and spy photos of this mythical machine have been circulating the web and print media since well before the current C6 generation Corvette debuted in 2005.
The program has reportedly been killed and revived several times, but it is now very much alive and we have all the details of the fastest, most expensive production 'Vette of all time. Given the recent developments with fuel economy regulations (35 mpg fleet average by 2020) this new King may well turn out to be last and greatest member of this blood-line. The Corvette will no doubt live on with a C7 set to debut in the next few years. But like the descendants of the Porsche 917/30 Can-Am car of the early 70s, nothing may reach the heights of this ZR1. Of course, the same has been said many times before and look at where we are today. For now just follow the jump to find out what $100,000 will soon be able to buy you.
Related: Detroit 2008: The Heart of the King, the LS9 is born!
[Source: General Motors]
click on any image to enlarge
At the initial introduction to the new ZR1 in the design dome at the General Motors Technical Center, Vice Chairman Bob Lutz explained the rationale behind the car. The team wanted to create a car that was both the fastest Corvette of all time, one of the fastest cars ever built and yet something that was still easy to drive on the road at lower speeds. According to Lutz, they wanted something that was docile around town, while still providing a smooth, never ending rush of power. While the Z06 is supremely fast on the track, many drivers have complained that the car can be scary to drive in the real world. The goal was to create a total performance machine that went well beyond the Z06.
To that end Vehicle Line Engineer Tom Wallace, Chief Engineer Tadge Juechter and the team have thoroughly re-engineered the C6 to create the ZR1. The aluminum and magnesium frame of the current generation Z06 forms the basis of the new model. On the outside, the visual changes from the Z06 are subtle but become more apparent as your eyes pour over the car.
At the front end, the main visual difference is the C6R-inspired splitter. As would be expected on a Le Mans winning race car, the splitter is made of carbon fiber. Moving around the sides past the front wheels, the normal single fender vent has been replaced by a pair of larger vertically stacked vents. There is clearly a lot of hot air that needs to be extracted from this engine compartment. Following the pattern set by the mid-engine cars like the Ferrari F430, Chevrolet has decided to show off its new engine, at least as much as they can with a front engine layout . Front and center in the middle of the once solid hood sits a transparent lexan window to display the new LS9 V-8 which we'll get back to later.
Along with the front splitter, the roof of the ZR1 is also made of visible carbon fiber. One of the problems with using unpainted carbon fiber for body work is that the resin oxidizes over time, turning yellow and cracking just like the old plastic rear windows on convertibles. To overcome this, GM materials engineers put a lot effort into developing an additive for the clear coat that could be applied to the carbon to preserve it for the life of the car. The ZR1 is the first car ever to have a carbon fiber clear coat that will last the life of the car. The chemical additive costs $60,000 a gallon and the clear coat with the additive mixed in comes to $2,000 a gallon. The visible carbon isn't the only such material on this car. The entire front clip is made of the same material, although those parts are painted.
Like the original 1990 ZR1, the heart of this new model is the engine. Like the Lotus designed LT5, the new LS9 shares the important dimensions of the classic Chevrolet small block V-8 including its ninety degree vee-angle and 4.4 inch bore spacing. Beyond that they share almost nothing. The LT5 was a dual-overhead cam four valve per cylinder design. The LS9 keeps the single camshaft in the valley of the block. While the LT5 kept the classic 5.7L displacement, and the current Z06 engine has grown to 7.0L the LS9 settles in at 6.2L. In its final iteration, the original LT5 in the 1990 ZR1 produced 405 hp and 71hp/L with the Z06 just beating that at 72hp/L although it's 7.0L displacement brings the total to 505 hp.
The new King drops the displacement back to the 6.2L of the current base Corvette. From there it's a whole new ball game. The LS9 adds a supercharger nestled in the valley of the block with an air-to-liquid inter-cooler sitting on top. The blower is a new 6th generation unit from Eaton. The 5th generation superchargers had three lobe rotors. The new unit has rotors with four lobes. This helps to improve the efficiency of the unit and lower parasitic losses. GM hasn't finalized the calibrations of the LS9 yet, so they aren't announcing power output. Tom Wallace did however say that the engine would produce a minimum of 100 hp/L and speculation has ranged as high as 650 hp. The final rating will probably be somewhere between 620 and 650.
In keeping with the desire to build a car that was eminently usable, GM made a major effort to minimize the hood bulge. The windowed hood has a maximum height only one inch taller than the Z06. Helping to achieve that, the engine has been lowered in the engine compartment to compensate for the increased height.
All that power is pretty useless if you can't get it to the ground. That requires a stiff chassis and a mechanically sound suspension system that can keep the rubber on the road. Speaking of rubber, the ZR1 has more of it than any previous production Corvette. Steering forces are transmitted through Michelin Pilot Sport 285/30ZR19s while tractive forces go through 335/25ZR20s at the rear axle. Those steam rollers also transmit the braking forces, which this car also has no shortage of.
Back in the C4 days, Corvettes were able to generate some insane handling numbers with their enormous for the time tires. The problem is they often could only manage this on a smooth test track surface. The flexible chassis and stiff springs meant the car often had trouble keeping its tires in contact with the pavement on real roads. The current C6 is an order of magnitude better. The chassis vastly more rigid, allowing the suspension to do it's job of following the road. Nonetheless the Z06 is still mighty stiff and often difficult to drive quickly on the road. The ZR1 actually has softer springs than the Z06 but uses the same magneto-rheological dampers as the Ferrari 599. The fluid in these units is filled with iron particles and the viscosity can be instantly changed by varying an electric current passing through it. Sensors in the car take measurements every 0.001 seconds and adjust the dampers every 0.002 seconds. The grip is promised to be superior to the Z06 on road and track while being much more comfortable.
During the presentation, Tadge held up a 15" Brembo carbon ceramic brake rotor. He explained that the Ferrari Enzo used these rotors on the front wheels. The ZR1 team put them on the rear wheels(!), while the fronts get 15.5" diameter pieces. The brake linings are squeezed around the rotors by 6-piston calipers in front and 4-piston units in back, also supplied by Brembo. Helping to distinguish the ZR1 from the more pedestrian Z06, the calipers will be painted a bright blue, while the lesser car keeps its red calipers. Moving up the drive-line from the wheels, the engine is backed up by a Tremec 6060 gearbox with unique ratios from the Z06.
So what does all this hardware do for you? Again, GM isn't talking final numbers yet, but it did replace the 200 mph speedometer in the Z06 with a new unit that goes up to 220 mph. The ZR1 is not cheap by any stretch of the imagination. At just over a third of the cost of a Ferrari 599, this is without a doubt a bargain among supercars. We can't wait for our chance to spend some quality time behind the wheel on the new road course that Maximum Bob had constructed at the GM Proving Ground. Then we want to try it on real world roads to see if this monster is really as livable as it's creators claim.