As spectacular as the new Corvette Stingray is right out of the box, Vette enthusiasts have never been the type to leave well enough alone. Given this insistence on excess, we'd be remiss in not revealing what sort of overabundance we can expect from several prominent companies known for premium Corvette enhancements.
These enhancements don't consist of random bolt-ons or boy-racer doodads. Instead, we'll be focusing on legitimate "tuner" Stingrays, dramatically modified Corvettes characterized by integrated performance and appearance packages that go more than one better than the factory original. The buyers of these cars demand something truly extraordinary, a Corvette that is not just a cut above, but one that takes a quantum leap into that rarified air of supercars.
One proviso, however: Given the relative newness of the car, many of these are works in progress, with build specs and performance outputs that were still being finalized as we went to press. Some items might have changed by the time you read this, so we recommend that you to check with these companies to confirm any details noted here.
Redline is an aptly named company that pegs the gauges in every sense of the expression, having already rocked the dragstrip with a cammed-and-nitrous-injected C7 that runs mid-10s at 130-plus mph in the quarter mile. Much of what was learned from this test mule will be incorporated into the company's new twin-turbo Adrenaline Rush. That's yet another fitting term, as this vehicle package is being developed to deliver an output that's nearly 58 percent greater than stock.
Getting this much of a gain required burning a lot of midnight oil, and also some insider contacts at GM that helped to decipher the complexities of the direct-injection system. As a result of all this diligence, Redline owner Howard Tanner has upped his original target output of 635 hp to something closer to 725 horses—and possibly even more.
One of the technology challenges has been cracking the Stingray's new E92 computer module and the intricacies of its torque-based control logic. Without access to this programming, no progress would be possible. Interestingly, Tanner points out that the onboard computer in the '14 Corvette is basically the same brain box found in the Chevy Silverado, but with significantly revised programming. After going through it, he admits that selecting a camshaft, a set of headers, and a cold-air intake for the C7 is much harder than with the C6 model.
Things get even more complicated when power adders increase the parameters programmed into the ECM, since the computer already has to manage numerous engine functions such as variable valve timing and active fuel management, among others. Exceeding those parameters can negatively impact volumetric efficiency, Tanner notes.
To overcome the computer safeguards, he pulled an E92 out of a vehicle and "bench flashed" new numbers into it after analyzing the "15-string polynomials." Even Tanner admits that this process involves some "crazy math," requiring the services of the computer experts at both HP Tuners and EFI Live.
What does all this mean for the Adrenaline Rush C7 in terms of hard parts? In addition to a pair of billet-wheel, ball-bearing turbos, Redline has been working with another company to develop a supplemental fuel-injection system that's integrated into a new intake manifold and controlled by boost level. This special manifold setup is what enables Redline to elevate the base Rush package from 635 to a staggering 725 horses. Tanner expects both packages to run in the 10s, with the more powerful model proving even quicker than the testbed C7 mentioned earlier.
However the final array of engine upgrades turns out, Tanner is aiming to get the attention of exotic-car owners who in the past might have sniffed derisively at the notion of an all-American exotic. To attract their interest stateside, he's including a carbon-fiber aero treatment, consisting of a functional front splitter, high-intensity driving lights, and a front-mount intercooler air scoop. Side skirts and a modified rear spoiler and fascia also furnish far more aggressive lines. For rolling stock, wider one-piece monoblock wheels with fatter tires (265/30ZR19 front, 305/35ZR20 rear) are hauled down by a set of carbon-ceramic brakes.
All of which supports the premise noted at the outset of transforming the production Stingray into a supercar, with a cohesive and comprehensive range of components. "The Redline Adrenaline package is about balance," Tanner confirms. "A true supercar has power, handling, and styling, and raises the adrenaline level to satisfy the true performance enthusiast. That's what this program is about."
The Adrenaline Rush package has a preliminary price of $45,500 (on top of the price of a Z51-optioned C7 Stingray). All installations will be performed at Redline Motorsports' Pompano Beach, Florida, facility, and a two-year, 24,000-mile warranty will be available on certain models.
Mention the term "tuner Corvette," and most enthusiasts immediately think of Callaway Cars. That shouldn't come as a surprise, considering that the Old Lyme, Connecticut–based performance company has been bolstering the power and panache of Chevy's two-seater for more than a quarter century.
For the new Stingray, Callaway is cooking up a supercharger system that's based on Eaton's existing Twin Vortices Series (TVS) 2300 rotor pack, yet optimized with a new manifold and intercooler, plus a Honker cold-air-intake system that improves inlet airflow. On the outlet side, a Callaway exhaust system is designed to reduce backpressure while adding the obligatory dose of aural excitement. All told, these components boost the Stingray's output to an estimated 610 hp.
As noted previously, the latest Chevy truck V-8s share their fuel injection, valve-timing controls, and electronic engine-management functions with the Stingray's 6.2L LT1. This commonality of components gave Callaway engineers a head start with their supercharged Corvette, since they had already done their homework on the blown '14 Callaway Silverado.
Reliability has always been a cornerstone of Callaway's performance program, and today the company provides a standard three-year/36,000-mile warranty (and optional five-year/100,000-mile powertrain service contract) through a network of authorized Callaway/Chevrolet dealers. Moreover, the latest Callaway Vette is designed to comply with 50-state emissions regulations. These facts alone separate it from the average tuner car.
As company founder/owner Reeves Callaway points out, "We're the benchmark of a modified Corvette—we invented the concept."
To ensure authenticity and prevent copycats, the new Callaway Corvette also includes exterior and interior badging and VIN-based identification, among other security measures. Cares are delivered with a personalized documentation package, and all vehicle history is maintained in Callaway's database. Introductory pricing of the '14 Callaway Corvette package is $23,000, with deliveries scheduled to begin around the time you read this.
Adding to the uniqueness of the project is the $15,000 AeroWagon option, inspired by the custom-built "shooting brake" cars of the 19th century. The latter term originally referred to a vehicle that could carry entire shooting parties, along with their guns and dogs. Later on the phrase was applied to any custom-built, two-door station wagon built on a factory car. While no hunting parties would likely fit into an AeroWagon, that wasn't the intent of the design.
"It was not an effort to create more interior room," Callaway explains. "It was really just a styling statement. We liked the shape of those limited-edition, coach-built designs."
Even so, Callaway points out that whenever you elongate the tail, it smooths out airflow. Accordingly the company claims that the AeroWagon bodywork should improve aerodynamics, allowing for top speeds in excess of 200 mph.
Available either a la carte on a stock Corvette or as part of the supercharged Callaway package, the carbon-fiber AeroWagon body conversion is scheduled to be available late this year.
Hennessey Performance has a thing for nice, round numbers, especially when they represent horsepower figures well above stock levels—specifically, outputs at the crank ratcheting up from 500 to 800 horses, or even more. You can achieve these numbers on a new Stingray by getting upgrade packages through an authorized Chevrolet dealership or having them installed at one of Hennessey's facilities. (There's one near Houston, Texas, and another in Lake Forest, California.)
While cost of the HPE500 upgrade ($4,995 installed) is not precisely a nice, round number, it does get you a lot of nice stuff: stainless-steel long-tube headers, high-flow cats, and midpipes that bolt right up to the well-engineered stock rear-section exhaust. A custom ECM calibration works in sync with these changes to maximize output and operating efficiency.
Pushing things to an even higher even integer is the HPE600 upgrade ($10,950 installed). Galloping into the 600-horse range requires an Hennessey-spec hydraulic roller camshaft, plus porting and polishing the factory cylinder heads for increased respiration. An even hotter tune optimizes fuel delivery and spark advance in this naturally aspirated package. Both the HPE500 and the HPE600 are covered by Hennessey's three-year/36,000-mile powertrain warranty.
Moving up the output chain, the supercharged HPE700 setup sells for $18,500, while the downstroke on the twin-turbo HPE800 is nearly $55,000. If those power numbers aren't nice enough, how about a grand worth of output from the HPE1000? Hennessey plans to build 12 of these monster-motor packages for 2014, each priced at $68,000.
In terms of likely popularity, the history of the company's C6 program provides some trends. "The HPE700 [has been] our bread and butter," notes Hennessey's Dave Golden. "If customers can afford an HPE800, they usually step up to the 1,000hp package, and we've sold 25 of those."
Whichever digits you prefer, Hennessey's exterior upgrades include CarbonAero bodywork consisting of a deep front splitter, side sills, and a more aggressive notched rear wing. Completing the package are H10 forged monoblock wheels, available in a variety of 18-, 19-, and 20-inch fitments. These 10-spoke alloys reduce total unsprung weight by a significant 19 pounds, as compared with stock Z51 rims.
The HPE500 and HPE600 are ready for delivery now, and the HPE700 should be available by the time you read this. The 1,000hp twin-turbo package should follow shortly thereafter.
Lingenfelter Performance Engineering
As you might expect from Lingenfelter, a hot mill is at the core of the Corvette tuner's upgrades, with everything else flowing from there. To wit: a blown version of the 6.2L LT1, unveiled at the SEMA show and rated at 720 hp and 655 lb-ft of torque. The only catch: "The blower won't fit under the [C7] hood, so we're looking at an alternative hood," says LPE honcho Ken Lingenfelter.
Of course, that's just the start of what promises to be a thoroughgoing lineup of Stingray performance hardware. In line with its current offerings for the C6, LPE will offer several packages for the '14 Vette, with power levels starting at around 500 hp and reaching as high as 900 hp with forced induction.
As a side note for fans of Chevy cars and trucks in general, LPE offers 10 crate engines ranging from 6.2 to 7.0 liters, with naturally aspirated outputs stretching from 550 to 660 hp and supercharged engines making 650 to 930 hp. LPE works with displacements ranging from the outgoing Silverado/Sierra pickup's 4.8-liter V-8 to a 7.2-liter stroker engine, while custom twin-turbo builds with up to 1,500 hp are available.
In fact, Lingenfelter says that advance work on the Silverado back in February 2013 gave the company a big head start. "Fuel delivery is our biggest challenge," he admits. So when the company's first C7 arrived on the transporter, "Our guys were like a trauma team," he laughs. "They jumped on it and had the engine out within a day."
Other LPE Stingray enhancements include everything from body-conversion components to various treatments for the suspension, brakes, wheels, and tires, offered either separately or on turnkey cars available through select GM dealerships. Pricing is still to be determined as of press time, but one thing will remain the same.
"We always warranty our work," says Lingenfelter. "We learned so much with the C6 program, so we don't make irresponsible power claims."