Code Breaker

The new-for-2011 Z07 option package makes the Z06 handle and brake like a ZR1.

Code Breaker 1
September 14, 2010

I landed in MKE where a 2011 Z06 was waiting for me. Equipped with the Z07 and CFZ packages, as well as the full 3ZL treatment and nav, this Inferno Orange C6 was ready to roll. So I got on the I-43 and headed north.

Average, reasonably well-adjusted consumers don’t know the alphanumeric codes for the options in their vehicles. Sure, they know that they’ve got the entertainment package, leather seats and V8 engine, but they don’t know the carmaker’s internal designations for these things. And they really don’t care. Not so with hardcore Corvette lovers, for whom breaking the codes is practically a rite of passage. Well, Chevrolet has two new ones for you to memorize: Z07 and CFZ, which we’ll get to in a minute. As for MKE, it stands for Milwaukee Mitchell Airport, don’t cha know?

Since the early 1960s, many of the option codes, particularly those designating high-performance hardware, have taken on a life all their own. A precious few have gone far beyond that, achieving a mystical status normally reserved for religious icons like the Holy Grail or that old Playboy magazine you dug out of your neighbor’s garbage when you were 10 years old.

The mere mention of certain codes to the cognoscenti can profoundly affect their physiological functions. Many moons ago, I told a devoted Corvette collector that I had just added an L88 to my stable—and for the first and only time, I saw his greasy old toupee spontaneously rise several inches off his gleaming, bald dome and hang in mid-air for a few seconds before unceremoniously plopping back down.

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The impact of now-legendary alphanumeric codes has not been lost on our friends at Chevrolet. As you’ve likely noticed, they have revived some of the more memorable ones in recent years, including of course Z06—though in this case it refers to the model, as opposed to the option group. While the Z06 designation may not have enough force to levitate a man’s toupee, it definitely will cause the hair on his neck to stand at attention. Introduced late in 1962 for the ’63 model year, Z06 denoted the Special Performance Equipment option package, which was designed to turn an otherwise ordinary Corvette into a competitive road racer. It included stiffer springs front and rear, a larger diameter front anti-roll bar and a unique, power-assisted heavy-duty drum-brake setup. All 199 1963 Z06s built came with a high-compression, solid-lifter, Rochester fuel-injected V8, and about five dozen were fitted with a 36-gallon fiberglass fuel tank.

Thankfully, the fiberglass fuel tank, drum brakes, mechanical fuel injection and just about every other component utilized in 1963 are distant memories at this point, but the spirit of the original Z06 permeates every inch of today’s Corvette bearing that magical name. Like its forbear, it is a true dual-purpose car, one equally at home on the street or on a racetrack. Some customers, however, want a Corvette that is even better on the street and even faster on the track.

Up until now, the only way they could satisfy this urge without turning to the aftermarket was to pony up six large and buy the supercharged ZR1. Today they have another option—option-code Z07 to be exact, the Ultimate Performance package. When GM offered to let me drive a fresh-off-the-assembly-line Z06 fitted with it, I was on it like a tramp on a kipper.

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The Z07 package, which adds a not-insignificant $9,495 to the bottom line, brings a Z06 several important steps closer to its ZR1 big brother by raiding that top-of-the-line Corvette’s parts bin. Easiest to spot are the wheels. Spun-cast for Chevy by Speedline, these 20-spoke alloys measure 10 × 19 inches at the bow and 12 × 20 inches at the stern (up from 9.5 × 18 inches and 12 × 19 inches, respectively) and are painted the same Competition Grey color. As on the ZR1, they are shod with Michelin Pilot Sport PS2 tires, instead of the Z06’s standard Goodyear Eagle F1 Supercar G2 tires (which, by the way, are new and improved for 2011). The Michelins are slightly larger than the Goodyears, sized 285/30ZR19 up front versus 275/35ZR18, and 335/25ZR20 at the rear in place of 325/30ZR19.

The Z07 rolling stock is anchored to suspension that differs from standard Z06 fare in two ways. The biggest change is the inclusion of Magnetic Selective Ride Control (MSRC) shock absorbers. This real-time damping system, which is tuned slightly differently than its ZR1 counterpart because of the Z06’s 158-pound lower curb weight, replaces conventional mechanical-valve shocks with electronically controlled units filled with a synthetic fluid that contains minute iron particles. When an electrically induced magnetic charge is present, the iron particles instantly align with one another, and by doing so they provide increased damping resistance. More current yields more magnetic charge and greater resistance in the dampers, while less current does just the opposite.

MSRC “reads” the roadway an amazing 1,000 times per second and reacts accordingly, increasing or decreasing current to each of the four dampers independently to increase or decrease damping resistance. The system’s 1-millisecond reaction time is so quick that if you encounter a huge pothole at 70 mph, the damper for the wheel that reaches the hole first will have appropriately adjusted before it actually reaches bottom. This remarkable performance makes the shocks incredibly adaptable. This trait allowed Chevy to fit Z07-equipped Z06s with slightly softer springs, improving ride quality and reducing axle hop without sacrificing high-speed stability or increasing body roll. In addition, the MSRC’s two modes of operation—Tour and Sport—allow the driver to tailor the system to his or her driving preferences.

The advantages of MSRC were crystal clear during hundreds of miles of driving on the roads of Sheboygan County. Located in eastern Wisconsin on the western shores of Lake Michigan, this area is subjected to extremely harsh winters. The traumatic effects of repeated freeze-thaw cycles, snow plows and ice-melting chemicals have yielded some rough road surfaces. While the interior of the Corvette was annoyingly noisy at times, especially on concrete roads where the incessant tire hum was repeatedly punctuated by thumping sounds over expansion joints, the Z07 suspension (set in Tour mode) absorbed the rough stuff with aplomb. A standard Z06 would not have fared as well.

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The Michelins play a role in this, as in my experience, these extended-mobility tires are more compliant than their Goodyear counterparts. Plus, they stick like glue. Together, these two traits make for a Corvette that instill absolute confidence 100 percent of the time. Even when driving hard, mid-corner bumps that would likely upset a stock Z06 are not a problem, a point that was underscored when I found myself following a mid-1990s Corvette on a twisty stretch at high speed. While the C4 was jumping left and right with every big bump or dip it met, my ’11 Z06 tracked straight and true.

The considerable benefits of MSRC suspension and Michelin Pilot Sport 2 tires are easily noticeable on the street, but the same does not apply to the another major component of the Z07 package: the braking system inherited from the ZR1. This is because the standard Z06 brakes, consisting of huge six-piston front and four-piston rear calipers squeezing 14- and 13.4-inch cross-drilled rotors, already delivers more stopping power than almost anyone will ever use on the road. But for those who feel an irresistible urge to be the biggest dog on the porch simply for the sake of being the biggest dog on the porch, or for anyone who really will put his or her car on a racetrack, anything less than the ZR1’s top-of-the-line carbon-ceramic binders simply will not do.

Extremely rigid six-piston front calipers squeeze humongous vented and cross-drilled carbon-ceramic rotors that measure 15.5 inches in diameter and 1.6 inches in thickness. At the rear, four-piston calipers hug carbon-ceramic discs sized at 15.0 inches across and 1.4 inches deep. The carbon fiber-reinforced ceramic silicon carbide material used to craft the rotors offers an unmatched combination of low mass, incredible strength and exceptional resistance to both wear and heat. Further aiding longevity and heat control is the total pad surface area, which is almost twice the swept area of standard Z06 brakes; enhanced airflow aids cooling, too.

Code Breaker 5

Though the carbon-ceramic brakes do have a distinctly different feel under all circumstances, their on-track performance is what makes them the cat’s meow. I didn’t have an opportunity to drive the Z07-equipped Z06 on track, but I have driven ZR1s on closed courses and can say this braking system is simply remarkable in terms of how it delivers intense stopping power in a predictably linear fashion while resisting fade. Behind the wheel of the ZR1, I also learned that placing the MSRC shocks in Sport mode pays real dividends on track, further sharpening the responsive handling.

Another new-for-2011 option group offered for the Z06 is the $3,995 CFZ Carbon Fiber Package. It includes the carbon-fiber rocker panels, front splitter and roof panel from the ZR1. However, unlike on the ZR1, these items are painted black, not clear-coated. The package also includes the ZR1’s full-width, body-color rear spoiler. The CFZ parts, like the Z07’s composite brakes, are functional in a track environment, where the aero appendages’ reduction in lift are useful, but in normal street driving they are more for show. That said, the CFZ carbon parts, which graced our test car, do make the Z06 look elegantly sinister, and the fact that they are the real deal and not tacky carbon-look add-ons is enough to induce lust.

However, be forewarned that the black paint on the CFZ pieces scratches easily when cleaned without a loving touch. Also, the front splitter is below and forward of the front fascia, so it will be the point of first contact with parking-lot curbs, steeply pitched driveway aprons, road kill, NYC manhole covers and other similarly situated heartbreakers. Unlike the Corvette’s flexible rubber front spoiler lip that often scrapes on things without doing any real damage, the crunch you hear when a Z07/ZR1 front splitter kisses the enemy will ruin your day.

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Aside from the Z07 and CFZ packages, there is not much that’s different for the 2011 Z06. Engine output from the free-revving 7.0-liter LS7 V8 remains a stout 505 horsepower, and the 6-speed manual transmission—Chevy doesn’t offer an automatic Z06—keeps its aggressive gearing, with first through third ratios of 2.66, 1.78 and 1.30. This translates into a 0-60-mph sprint of just 3.7 seconds, a quarter-mile pass in 11.7 seconds at 125 mph and a top speed of 198 mph.

The raw stats may speak for themselves, but they don’t tell the entire story. Every time I get into a Z06, it feels as though I’m strapping on a lethal weapon. This Corvette is truly exhilarating. Its prodigious power and relatively light weight (3,175 pounds with or without the Z07 package—the Z07’s heavier wheels, tires and shocks are offset by its lighter carbon-ceramic brakes) make standing starts and freeway merges sweet indeed. The Z06 is breathtakingly fast.

The quality and comfort of the Corvette’s interior have been widely criticized over the years, and more than a few pundits still consider it the car’s weakest link. I have no complaints about the materials used or the quality of its fit and finish, and with one exception find it very comfortable. That one exception is the configuration of the left armrest; my elbow rests right on the junction where the padding meets the door pull, which becomes annoying during long drives. (Not sure how I’d remedy this if I owned the car, but I’d definitely have to do something.) My only other complaint concerns the less-than-intuitive functionality of the outdated satellite navigation system.

It will be interesting to see how the Z07 and CFZ option packages perform in the marketplace. Combined, they add $13,490 to a 2011 Z06’s $74,305 MSRP, bringing the total with the inevitable $950 destination charge to $88,745. That is real dough for an average bloke, but at the same time it’s more than $22,000 shy of the ZR1’s price tag. In terms of raw acceleration and top speed, the ZR1’s extra 133 horsepower more than make up for its extra girth, but the Z07-equipped Z06’s lighter weight should give it an edge in handling and braking, and Chevy engineers admit that it is the most track-worthy Corvette on offer. Factor in the $22,000 in savings, and a Z07/CFZ-optioned Z06 makes a mighty strong argument for itself. These alphanumeric codes deserve a place in Corvette history.

Also from Issue 61

  • The 1964 coupe
  • Best Corvette Buys for $8K
  • GM’s Performance Build Center
  • 1968 Big-block Coupe
  • 1966 Coupe
  • American Le Mans Series Report
  • How-To: Tie-rod Ends
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