The 2006 Z06 is constructed around a perimeter-style frame just like other Corvettes, but the main rails beneath it are hydroformed out of aluminum instead of steel. The front engine cradle on the street car is made of lightweight and robust magnesium. And where the final year of the old Z06 included a carbon-fiber hood largely for commemorative-edition fanfare, the new Z06 takes advantage of that exercise by including carbon-fiber front fenders and wheelhouses plus sheet-carbon floorboards surrounding the model's traditional balsa-wood core. There's a lightweight, non-removable magnesium roof panel that simultaneously lower the Cg and greatly increases rigidity. And despite the addition of numerous beefier, heavier performance components such as larger brakes, heavier antiroll bars, and wider wheels, the 2006 Z06 weighs nearly 50 pounds less than the standard C6 (or some 3130 total) thanks to the extensive use of advanced chassis and body materials.
On the outside, the Z06 body includes several visual updates to separate this FIA stalking horse from the cooking C6. The more obvious changes include a central hood intake, flared wheelarches stretching a full three inches wider than standard, cooling ducts for the rear brakes, stouter front-fender vents, and reworked nose and tail caps. It's a relatively short list of differences, but the changes are substantial enough to ensure that the new Z06 stands out even more than the much loved C5 version. On the inside, unique lighter, grippier leather seats are joined by a smaller and much more attractive three-spoke wheel, standard HUD and air conditioning, and reduced sound insulation.
Still, like its predecessor, the majority of the upgrades have taken place underneath, starting as always in the engine compartment. Followers of the C5R racing effort are well aware of that car's potent powerplant, a bored-and-stroked interpretation of the familiar Gen-III V8. With a huge 4.125-inch bore and four-inch stroke giving a Rat-sized 427 inches of displacement, the "smallblock" designation was somewhat of a misnomer for that engine, even though it retained the same external dimensions as its LS1/LS6 forebears.
That same 427 is slated to continue in the C6R, but thanks to the much closer relationship between road and race trim demanded by new FIA/ACO/ALMS rules, the roadgoing Z06 will get its own 427 (Mat-motor? Rouse-motor?) for 2006. The numbers are nothing short of staggering: a full 500 horses at 6200 rpm, 475 lbs-ft @ 4800, a sub-four 0-60 dash, and quarter-mile sprints in under 12 seconds.a set of bogus plates and a false identity card would be nice additions to the glovebox. Despite being essentially a re-thought race motor, this new Z06 mill (called LS7 by GM) also promises remarkable tractability, thanks to receiving the same level of engine-management attention given its junior cousins.
While its exterior dimensions and general layout are shared with the LS2, the new LS7 is based on a separate block casting and assembled by hand at GM's new Performance Build Center in Wixom MI. The punched-out aluminum block carries lightweight titanium conrods attached to aluminum flat-top pistons giving 11.0:1 compression. Six-bolt, CNC-machined, forged-steel main caps are needed to keep the assembly together.
CNC machining is also utilized on the new aluminum heads, which boast an 18% improvement in airflow over LS2 units. Nearly straight tunnel-like intake runners feed the air/fuel charge through huge 2.2-inch titanium intake valves while 1.62-inch, sodium-filled hollow exhaust valves let spent gasses back out. A hydraulic-roller cam provides a significant .591-inch lift, even before taking into account the super-high-ratio rocker arms.
As on the C6R's race engine, hydroformed four-into-one tubular headers carry the exhaust from the heads, after which it's routed into a model-unique set of catalytic converters and dual-mode mufflers. The latter include a vacuum-operated valve that stays closed at low revs to manage noise and opens at larger throttle angles for minimum backpressure. The engine is lubricated by racing-style dry-sump oiling, which ensures complete lubrication under all cornering loads. Despite the massive displacement, lightweight internals give the LS7 a 7000-rpm redline in roadgoing trim .a figure more commonly associated with multivalve twincam Fours than traditional pushrod V8s.
The LS7's significant output is channeled through a lightweight flywheel and clutch assembly feeding a strengthened version of the previous model's Tremec six-speed transaxle. This rear-mounted gearbox includes a pump that routes transmission fluid through the front radiator stack for additional cooling, after which the chilled fluid is also used to help cool the lubricant in the limited-slip diff on the way back. The latter unit features an enlarged ring-and-pinion assembly and turns upgraded halfshafts and U-joints.
Huge 325/30ZR19 rear Goodyears put the power to the ground; the matching Eagle F1 Supercars up front are 275/35ZR18s . These ride on Z06-specific split-spoke alloys measuring 18x9.5 front and an imposing 19x12 at the rear . The basic suspension layout is shared with the standard Corvette, but performance-directed upsizing of the spring rates, antiroll-bar diameters, and braking hardware sets the Z06 apart. The stopping is done by 14-inch vented and crossdrilled rotors up front and 13.4-inch pieces out back, an increase of more than an inch at both ends. New six-piston calipers in front and four-piston units in back handle the clamping needs.
Corvette enthusiasts will undoubtedly applaud the comprehensive component list associated with the new Z06, but all that hardware is certain to come with a price. While the previous Z06 was able to hit showroom floors with a very digestible sticker thanks to its focus on just a few well-placed modifications, the more complete package that comes with the C6 version will inevitably equate to a tougher-to-swallow tariff.
Chevy insiders have sworn on their dead grandmothers' graves that the base Porsche 911 price was the program's target, yet it's hard to believe all that carbon, aluminum, and other specialized hardware can really be delivered in the high-60s; even a $75,000 sticker would be a spectacular value, especially compared to the six-figure tab of the Ford GT. On the other hand, anything more than that sum is likely to raise unfortunate accusations of ZR1-itis.it's hard to see how Chevy can win either way.