A large front-mount intercooler...
A large front-mount intercooler combines with methanol injection to cool the intake charge.
As for engine management, the factory PCM is tuned with HPTuners software, while the mass-airflow system is replaced by a two-bar speed-density operating system. The only ignition-system upgrade is a set of NGK TR6 spark plugs.
STS puts the output of the turbocharged LS3 at 702 hp and 714 lb-ft torque, which translates into a gain of 33 hp per pound of boost. Dyno testing shows the ZR7 making 603 hp and 610 lb-ft at the wheels. Even with this impressive output, the car maintains an ease of use uncommon to similarly modified Corvettes. "The car makes an excellent daily driver while still having that kick-in-the-pants power capable of thrilling even seasoned horsepower addicts like myself," says Squires.
STS 3-piece forged wheels...
STS 3-piece forged wheels conceal massive Baer brakes that are capable of hauling the ZR7 in from its 220mph top-speed.
The acceleration is simply mind-melting-60 mph arrives in a scant 3.5 seconds, and the quarter-mile whizzes by in only 10.8. For those who dare and have a lengthy enough strip of pavement (or perhaps salt), the top speed is an epic 220 mph. And Squires isn't shy about sharing his Corvette's performance with other motorists. As he tells it, "I love pounding on the bullet bikes on the freeway. It leaves them in a dazed and confused state of 'What just happened?'"
Despite the monumental swell of torque from the engine, the drivetrain remains remarkably stock. The only changes are the addition of a Fidanza twin-disc clutch and aluminum flywheel. This setup reduces the rotating mass and makes for easy downshift rev-matching. Brawny Pfadt engine and transmission mounts have also been installed for added support.
With such aggressive looks...
With such aggressive looks and performance fit for social misfits, the ZR7 leads one to wonder just what they're putting in the water in Utah.
Conventional wisdom would lead one to believe that performance on the level of the ZR7 must come at a price. It's the natural order of things that cars with tremendous power must have exiguous fuel economy, but the ZR7 defies this logic. "People are understandably blown away at the massive power the car delivers, but what really gets them is the fuel mileage," says Squires. Driven with a modicum of restraint-admittedly a challenge-the ZR7 sips fuel in a fashion one would expect from an anemic econo-car. STS has observed fuel economy of 24 mpg in city driving and 36 mpg on the highway. The company also claims that its turbo setup will reduce emissions by about 75 percent over stock, and the ZR7 package is currently awaiting CARB approval. This enviro-consciousness makes the ZR7 a true "green" supercar.
Wider fenders add nearly 6...
Wider fenders add nearly 6 inches to the stance of the car and easily accommodate the substantial tires.
Not content to impress only drag racers and speed freaks, Squires was determined to make the ZR7 handle as well. (He also owns a twin-turbo '01 Z06 that's purpose-built for drifting.) Improving the stock C6 suspension is no small order, but sway bars and adjustable coilovers from Pfadt Race Engineering proved more up to the task. On the skidpad this setup has tested at more than 1.2g. "With the recently completed Miller Motorsports Park right in our backyard [STS is based in Orem, Utah], this car will be spending some time at the track for sure," Squires assures us. While the suspension provides track-ready capability, it's also well-balanced for use on the street.
Such immense performance in the hands of mere mortals requires the ZR7 to possess serious stopping power. "With the massive torque and the deceptively quick acceleration of the twin-turbo package, you can quickly find yourself at warp speeds and in need of doing some panic braking," Squires explains. To slow things down, identical Baer Extreme big-brake kits featuring six-piston binders with 14-inch cross-drilled-and-slotted rotors are positioned fore and aft.