Overachiever

Also from Issue 89

  • 1,000-hp Twin-Turbo C6
  • Buyer’s Guide: C4
  • 1988 Coupe
  • Tech: Performance Data Recorder
  • Harley Earl’s C2
  • 1967 Small-Block Coupe
  • 1969 L89 coupe automatic
  • Racing: C7.R
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Both of these rear-mounted gearboxes are connected to the LT4 engine by a carbon-fiber torque tube. As a result of the harmonic imbalances created by the C7’s cylinder-deactivation system, Chevrolet had to go to a stronger steel torque tube on the Stingray, which added mass compared to the C6’s aluminum unit. The 2015 Z06’s carbon-fiber torque tube has been engineered to handle the LT4’s tremendous amount of twist while being even lighter than than the previous alloy version.

As with the base Stingray, manual-transmission Z06s will come equipped with Active Rev Match that can be turned off via steering-wheel paddles if the driver wishes. Speaking of the steering wheel, it receives a flat bottom on the Z06; other than badging, this is the main difference between Z06 and Stingray interiors. (By the way, the Stingray moniker is indeed dropped from the Z06’s model designation.) However, the C7 Z06’s cockpit offers something new when you compare it to those of its C5 and C6 predecessors: a removable roof panel. Because the new Corvette’s aluminum frame was designed with this feature from the outset, it made sense to include it on the Z06. Even with the roof panel removed, the C7’s structure is 20-percent stiffer than the C6 Z06’s fixed-roof alloy frame; with it in place, it is a full 60-percent stiffer.

Exterior Design:

Downforce Producer

Not surprisingly, virtually all of the Z06 exterior design changes were driven by functional considerations. According to Corvette Exterior Design Manager Kirk Bennion, one goal the design team began with in transforming a Stingray into a Z06 was to “widen its stance to improve its stability and accommodate wider tires for better grip.” The Z06 comes with Michelin Pilot Super Sports sized 285/30ZR19 up front and 335/25ZR20 at the rear, compared to the Stingray’s standard 245/40ZR18s and 285/35ZR19s. The Z06’s body is correspondingly wider, 2.2 inches in front and 3.2 inches in back.

Added cooling capacity for the engine, transmission, differential and brakes was another important consideration in the track-oriented car’s exterior design. Very large front fender vents exhaust more air from the engine compartment, while unique air blades over the inlets on top of the rear quarter panels channel about 50-percent more air into the transmission and differential cooling ducts than on the Stingray. The Z06 rear fascia, which is wider than the Stingray’s, has larger vents adjacent to the taillights to help expel the added air volume. Large ducts in the corners of the front grille bring cooling air to the front brakes. As has become a Z06 hallmark, scoops in front of the rear wheel openings direct air to the rear stoppers.

Perhaps the most interesting cooling feature, however, is the new front grille. According to Bennion, the beautifully crafted egg-crate design flows more air than the opening would with no grille at all. “It actually enhances the airflow,” says Bennion, “and that’s due to its construction, and how we used minimum draft angle and how we oriented the shape. You start off with minimum material thickness and you minimally draft that back, so if you were to look at those grille blades, they’re only about 1.5 mm thick but they’re drafted back about 3 degrees—and for a mass-produced car that’s about the outer extreme. What that does over that length is streamline and actually increase airflow.”