There are few better cars to bring the pushrod V8’s bellow to Italian circuits than the Z06-R GT3. This monster, closely tied to the production C6 Z06, proves just how incredible the platform is. Though its engine specs don’t differ from the production car much, the GT3’s weight reduction, spiffy gearbox, and stiffer chassis made it a force to be reckoned with during its heyday in FIA GT3 and ADAC GT. As we see in this incredible display above, the Z06-R can reach some outrageous speeds along Imola’s long straights.
American Roots, German Refinement
Considering how closely this car is related to the production Z06 it’s based on, it’s hard to say whether it’s truly an American or European product. Callaway Competition, a German offshoot of the famed American tuner, took a production C6 Z06 and made it compliant with FIA safety regulations. After Callaway Competition replaced the original aluminum chassis with a steel unit to allow the welding of an FIA safety cell, they gave it the sort of footwork a racing car needs.
As we can see from this incredible footage above, big Alcon brakes, sporting six-piston calipers in front and four-piston calipers in the rear bring the Corvette down to reasonable speeds. Top-dollar Moton coilovers in the place of the standard leaf springs, give it the adjustability and road-holding it requires.
With 325-section slicks at all four corners, the cornering performance is mighty — as is the way it can deploy its tidal wave of torque without much wheelspin. That said, while it’s relatively soft and compliant over Imola’s curbs, this wide-tired machine requires its driver to have their wits about them. As we can see from the footage below, the car is very snappy when it eventually lets go.
Despite tacking on a great deal of heft with the steel additions, Callaway Competition managed to keep the weight down with lightweight components. Magnesium OZ Racing wheels, a plexiglass rear window, and a body made largely with carbon-reinforced plastic bring the Z06-R GT3’s weight down to roughly 2,650 pounds. This svelte figure, when paired with a broad powerband and excellent traction, allows the Z06-R GT3 to sprint through the quarter-mile in just 10.1 seconds — nearly two seconds faster than what the production Z06 can muster.
Some of that speed can be attributed to the addition of a sequential shifter, too. While the earlier versions of this car retained the factory TR6060, later versions — this one included — sported a Hewland six-speed sequential. Weight and quicker shifts make up all the difference in the quarter-mile since the engine didn’t get much extra over the factory output.
A Racing Car with a Road Car’s Powerplant
While keeping most of the motor standard, APP Racing Engines fitted the LS7 with a special dry-sump lubrication system, CP pistons, and a special camshaft to better suit racing conditions. These modifications only bumped power to 520 horsepower and 442 lb-ft of torque at 5,000 rpm, even despite lowering the redline. Due to the FIA-spec intake restrictor these cars were required to run, it made sense to drop the engine’s shift point to about 6,300 rpm from the factory 7,000 rpm — but that didn’t ruin the soundtrack any.