2006 Chevrolet Corvette Specter Werkes - Sports Corvette Group 6

There's something intrinsically appealing about a Corvette that appears to be bulging at the seams. The widened rear fenders of the '90 ZR-1, for example, wrapped around the steamroller Goodyears like Cindy Crawford wearing a just-tight-enough pair of jeans in a Guess? ad. The same goes today for the '06 Z06 and its flared bodywork.

Corvette builder and racer Jeff Nowicki, of Specter Werkes/Sports, knows all about the subtleties of the Corvette form. He's been enhancing the Vette's shape at his Troy, Michigan, shop for the better part of 10 years, and he's the first one to admit too much of a good thing can ruin the sensual shape of the car.

"The Corvette's [shape] has always been carefully proportioned," he says. "There are ways of accenting it that enhance the muscular, performance ethic, but too-wide panels or outlandish wings detract from its essence."

Nowicki transferred his philosophy into fiberglass with the original, C5-based Corvette GTR. These made-to-order supercars featured wider replacement front and rear fenders, as well as correspondingly widened fascias. The GTRs had a more dramatic "Coke bottle" silhouette, which helped dramatize the cars' lines and cover wide rubber, but the uninitiated had to look twice to see the difference-unless the GTR was parked next to a "skinny" C5.

The GTR was a complete, turnkey car offered through two exclusive Chevy dealers, but Specter also developed a group of a la carte exterior, interior, and performance upgrades under the Group 5 label. These weren't-and aren't-simply the GTR components offered to the DIYer. The Group 5 components consist of unique ground effects, fascias, spoilers, and more. And rather than being sold through a couple of dealers, the Group 5 parts were offered to anyone who wished to order them directly or drop off his Vette at the Specter shop for upfitting.

Now, Specter Werkes has launched the Group 6 lineup for the sixth-generation Corvette. Yes, it's a looker, with fender flares and an appropriately sized rear spoiler, but it's also a Z06 fighter. Specter's prototype car pumps out more than 500 normally aspirated horses from the 6.0-liter LS2 V-8.

Like the GTR and Group 5 designs, the Group 6 complement of exterior upgrades embellishes the factory's form without cartoonish exaggeration. But where the C5 exterior components offer a smooth, tailored look, the Group 6 has a harder, racetrack demeanor-as if the designer sport coat has given way to a bicep-stretched T-shirt.

"The basic form of the C6 is a race car, and the Group 6 components build on that," says Nowicki.

The success of Corvettes-including the LeMans-winning factory team-on the racetrack undoubtedly influenced the Group 6's design. Several of Nowicki's customers have left cars at the shop with instructions for Specter Werkes to give them the look of a road-going racecar.

Well executed in form and proportion, the bolt-on Group 6 parts include an extractor hood, an aero package with rear spoiler, and rear wheel flares. The silver prototype in our photos wears HRE 840R wheels wrapped in Michelin PS2 rubber, sized 275/35-19 in front and 335/30-20 in the rear.

"We wanted to give the car a more aggressive stance, while keeping the identity of the production design," Nowicki says. "The front chin is functional, channeling air to the brake ducts, and gives the car a meaner look. The rear wheel flares allow 12-inch-wide tires to fit."

Specter Werkes/Sports offers the individual components of the Group 6 package separately.

Naturally Aspirated
With the willing, 400-horse LS2-which retains elements of the previous LS6 engine, including the cylinder heads-as a starting point, the Group 6's engine was treated to Specter Werkes' "Matrix 1" makeover, which included a special-grind camshaft, CNC-ported cylinder heads (with larger valves), a Lingenfelter cold-air box, LG Motorsports long-tube headers (with 3-inch X-pipe) blowing into a Corsa exhaust system, and a pan full of Mobil 1 oil. It's a relatively simple combination that, while requiring some careful tuning for optimal performance, delivers 525 hp and 435 lb-ft of torque.

This is race-car horsepower and time-warping torque. Besides the output, however, is the Group 6's rumble and idle quality. It barks to life with a raspy growl, thanks to the long-tubes and Corsa pipes, but it settles into a thumping, low-rpm idle that instantly reminds us of the solid-lifter days of yore. The moment you hear it, you think one thing: "Man, that thing's got some cam." With 500-plus horsepower, the Group 6 has no trouble hazing the nubs off the new Michelin PS2s. Throttle response is more immediate, too, thanks to a few well-placed taps of the laptop keyboard.

Surprisingly, all this power is channeled through an otherwise stock drivetrain. The cooling system is stock, and so are the six-speed manual transmission and clutch.

"All the factory parts are more than adequate for the power," says Nowicki.

Those with a stronger need for speed can order up a stroked Matrix II powerplant, a 7.0-liter C5-R-derived engine, and a Matrix SC engine equipped with a MagnaCharger blower. These upgrades ain't exactly cheap, but as the axiom goes, speed costs.

The full Group 6 treatment also encompasses suspension and brake enhancements, including Stop Tech ST-60 brakes with six-piston front calipers and four-piston rear calipers clamping down on drilled rotors-including huge 330mm (13-inch) units up front. The suspension receives the T-1 upgrade kit from GM, which includes new front and rear springs, stabilizer bars, upper and lower front A-arms, and stronger links.

Inner Style
Along with the exterior and performance upgrades, the Group 6 package also includes a sumptuous upholstery upgrade, with Spinneybeck Italian suede. The burgundy-color material, embroidered with the Group 6 emblem on the headrests, adds a decidedly upscale aura to the Corvette's cabin, complementing the 525 hp in true velvet-hammer form.

All told, the exterior, interior, and performance enhancements of the Group 6-including installation, tuning, and paintwork-run about $30,000. Even with a brand-new Corvette, that's not much more than the cost of a new Z06. There's also the intangible quality of exclusivity-not too many other enthusiasts will have one.

What we really like about the Group 6 lineup, however, is the cafeteria-style options menu. Don't like the extractor hood? Leave it off. Want everything but the T-1 suspension? No problem.

"It is first and foremost the customer's car," says Nowicki. "He tells us how to build it."

While the quantifiable traits of the Group 6-such as the Matrix I engine's dyno numbers or the skidpad performance of the T-1 suspension and Michelin PS2 tires-are easily justified, the intangible traits are the package's real strengths. The hunkered-down stance, just-try-me idle quality, and race-ready form are simultaneously unmistakable and understated.

For those who appreciate such a design philosophy, the Group 6 backs up its form with searing function.

Inside Specter Werkes/Sports
For the past 16 years, Jeff Nowicki has built a reputation crafting Corvettes from his facility in suburban Detroit. He founded Specter Werkes/Sports in 1990, and today it not only builds Corvettes and Corvette upgrades, but does design work and prototype building for the OEMs. The company also includes vehicles such as the Cadillac CTS in its enhancements repertoire. (The Pontiac Solstice is another possibility being considered.)

Not bad for a guy who started out working for various prototype shops, as well as GM Design, while taking side projects after hours.

"It all grew out of the work I was doing outside of my regular jobs," says Nowicki. "I had the shop going while I was at GM, and it just became clear that this is what I needed to do."

Design work was in Nowicki's blood. His father, Ron Nowicki, worked at GM Design for 36 years and was the chief studio engineer for the C5. By January 1998, Specter Werkes built its first GTR, which is still owned by its original owner-Chevy dealer Jeff Cauley. About 30 of the exclusive cars have been built since, along with countless other special customer projects, race cars, and Group 5/Group 6 cars.

The Specter Werkes shop typically contains three or four cars in various stages of construction. On our recent visit, the projects included the GTR conversion of an '04 Corvette Z06 Commemorative Edition, which, when finished, will still wear the factory-style blue paint and graphics. It is the third GTR Specter has built for an enthusiastic Colorado customer.

"Customers are extensions of our team," says Nowicki. "We invite them to track-day events and other get-togethers. It's like a fraternity of like-minded enthusiasts."

At track days, Nowicki is as much participant as host. He holds four SCCA divisional autocross championships, two SCCA road-racing championships, and has participated in everything from the World Challenge to the '04 Grand-Am Rolex series.

But even the best customers aren't privy to the OEM design work that goes on at Specter Werkes. In fact, there were parts of the Specter facility we couldn't photograph: the curtained areas that contained ongoing modeling and prototype work. We'd tell you more about it, but we'd have to kill you afterward-if Nowicki hasn't already killed us in the meantime. He is famously and rightfully protective of this work, and no one simply waltzes back to the shop's work area without his knowledge or escort.

Let's see . . . design work, Corvette construction, prototype building, and successful racing experience. Is there a downside to Nowicki's life?

"Well," he says, "My wife, Brenda, won't let me near her when I smell like fiberglass resin."