All the Changes That Turned the Chevrolet Corvette Stingray into the Z06

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chevrolet corvette z06 2023

Marc UrbanoCar and Driver

The new 2023 Z06 is a special car, and for that it requires a long list of engineering changes that go, literally, from the street to the roof. Some of them are clearly visible to the naked eye, but many of them are below the surface. The Corvette engineering group has extensive experience developing standard models into higher-performance track killers. Witness three generations of the Z06—C5, C6, and C7—from 2001. Here’s what they revised on the already impressive base C8 Stingray to turn it into a very focused Z06.

Read Our Complete Instrument Test for the Z06

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This new LT6 V-8, codenamed Gemini, is the foundation on which the new Z06 is built. No previous Corvette has had a new, bespoke engine without one in common with other GM engines. And this one is special: a naturally aspirated 32-valve cam flat crankshaft design inspired by the Ferrari 458 engine. It keeps its power through ultra-high revs: its 670-hp peak hits 8400 rpm; its 460 pound-feet of torque arrives at a soaring 6300 rpm; and it redlines at 8500 rpm. This is exhaled through a clever driver-adjustable exhaust system that can vary the engine music from mild to wild. The engine is assembled by hand by a single engine maker at the Corvette assembly plant in Bowling Green, Kentucky.

With 180 more horsepower to handle than what the base C8’s 6.2-liter V-8 makes, the Vette’s dual-clutch automatic transmission takes time in the gym. The transaxle casing and bellhousing are stronger, the six-plate coupling is sturdier, and the output shaft flange is larger and bolted to the higher-strength half-axle. One of the clutch packages gets an extra clutch plate. The internal lubrication system has been revised to handle higher cornering forces and does not require extra grease filling for track events. (The trans in the C8 Z51 track pack model does it.) A final refinement is a 7 percent shorter final-drive ratio to help the high-revving engine get to where it pleases faster.


Better Thermal Management

The Z06’s powerful V-8 generates more heat than the base C8 engine. And the LT6 needs some extra cool work; engineers discovered that this was one of the secrets that enabled the small diameter, low-friction main bearings in the jewel of the Ferrari 458 engine, a design element incorporated into the Z06 V-8. The base C8 has a total of three coolants, two for the engine coolant located at the outboard end of the front fascia and one at the right side air inlet for cooling the oil. The Z06 is equipped with two additional coolers, one located in the center of the front fascia and the second in the left side air intake of the body. A more powerful front fan increases airflow by 50 percent; larger side air intakes deliver 20 percent more air. Owners can open the cover on the front fascia to increase the center grille opening by 75 percent to let more air flow into the center radiator. The car also gets a 20 percent larger AC compressor to keep the cabin cool on hot days. Good.

The C8’s open-roof aluminum structure was designed from the start to handle the higher cornering loads of the Z06 and Z07 equipped models. No structural reinforcement is required, or changes to suspension arms or other major chassis components. The spring rate for the standard Z06 is up 30 percent from the C8 Z51, and bushing stiffness has been increased. Engineers say that the tight springs keep the ultra-wide edges of the tires straighter during cornering and also reduce body roll enough so that the Z06 can survive with a slightly smaller anti-roll bar than the C8 Z51. In addition, engineers say that increasing the driving frequency—the tightness of the suspension-and-tyre system as a whole—is a cool move because it gives the car a quick reaction, a ready-to-go feel that matches the nervous energy. from LT6 V-8. The Z07’s springs are 10 percent stiffer. All Z06s get the magnetorheological (MR) damper standard. Tire size has increased to 275/30ZR-20 at the front and 345/25ZR-21 at the rear—an increase of 30 millimeters at the front and 40 millimeters at the rear compared to the already wide rubber of the C8 Z51. The standard Z06 comes with Michelin Pilot Sport 4S tires. The Z07 gets the new Michelin Pilot Sport Cup 2 R track-attack rubber — which is pretty much the same as race tires in that you can make road tires and still be road legal. Optional carbon fiber wheels sharpen steering response to such an extent that the steering rack must be recalibrated to eliminate turn-in dartiness. During extensive on-track development, engineers found that reducing the rotational inertia of the carbon wheels increased lap times at two-minute laps by 1.0 to 1.5 seconds.

What is accelerated must be slowed down. So all Z06s are equipped with oversized Brembo six-piston front brakes and four-piston rear brakes, with different caliper designs for the steel and carbon ceramic rotors. Z06 standard running steel rotor; carbon-ceramic is optional. All Z07 package cars get the carbon-ceramic standard. Both brake packages are fully trackable according to Corvette engineers.

Unsurprisingly for such a powerful track-focusing weapon, the Z06’s aerodynamics have been improved to deliver more downforce, which improves traction and stability. The standard Z06 aero package looks relatively ordinary but is very effective: it has a larger rear deck wing than the C8 Z51 with more pronounced webbing; changes under the nose increase front downforce; ducts under the car were added for additional rear brake cooling; and the cover on the front fascia was removed to improve engine cooling. Some changes work well, generating 362 pounds of downforce at 186 mph—if you can go that fast. The Z07 gets a max-downforce setting, which is also available as an option on the base Z06. It incorporates a large rear deck wing; full forewings under the forewings; strakes under the car that channel air to the sides to help suck the car down; larger front splitter; and dive the plane in the front corner. The change produces 734 pounds of downforce at 186 mph. Besides, we think they’re broadcasting the bad temper of this hot-rod Corvette.

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