Power routes through an Exedy carbon-fiber clutch to a G-Force T56 six-speed transmission. The stock 3.31 gears are still in the car, though Mark Williams halfshafts direct power to the Pilot Sports. Each corner is fitted with Baer Extreme-Plus 6R six-pot brakes, a good idea when you have this much power under your right foot.
The GMS Z06 doesn't exactly look tame, thanks to its flamed paint, Classic Design Concepts Tiger Shark front and rear fascias, RKSport carbon-fiber hood, and Catz HID conversion. Yet it can be surprisingly docile when you resist the urge to stand on it. In putt-putt mode, about the only tip-off to the car's potential is the whine from the T56's straight-cut gears.
As we idled down the freeway on our way to the photo location, J.R. was happy to show us, via the Corvette's onboard computer, that it'll return respectable mpg if you behave. (Yes, it felt odd to talk about fuel economy in the context of a street Vette that'll turn the quarter-mile in less than 10 seconds, but it's a hard topic to avoid these days.) He was well on his way to achieving 20-plus mpg until we asked for burnouts for the camera. "Those burnouts just did us in," he said later, pointing at the 14.1-mpg reading above the steering wheel.
That ain't bad, especially since our burnouts weren't entirely to blame for the dip in fuel economy. On the way to our shoot, J.R. couldn't resist giving us a taste of just what this Vette can do. Stomping the accelerator is a traction-avoidance maneuver that'll just vaporize the tires. But when J.R. leaned into the pedal, the surge to speed felt like a meaty hand shoving us back into the seat, while the needles in the dash tracked not just engine and road speed but our own adrenaline spike. Just as quickly, the big Baers hauled us down to match the flow of traffic, and we had a chance to catch our breath.
So, do customers ever ask for more than this? we asked.
| Spec Sheet |
| Car: | '04 Z06 Corvette |
| Owner: | Granatelli Motor Sports |
| Block: | GM LS6 with Darton sleeves |
| Displacement: | 427 cubic inches |
| Compression Ratio: | 8.8:1 |
| Heads: | GM LS6, ported to Stage 5 by Motorsport Technologies |
| Valves: | Manley,2.05/1.62-in |
| Camshaft: | Cam Motion |
| RockerArms: | Granatelli rail-mount rockers |
| Pistons: | Ross |
| Crankshaft: | Lunati |
| Rods: | Lunati |
| Intake Manifold: | FAST |
| Throttle Body: | GMS-modified LS2 |
| Fuel Injectors: | ACCEL 55-lb/hr |
| Fuel Pump: | Twin Bosch 930 Turbopumps |
| Ignition: | Stock with Granatelli 0-ohm wires |
| Engine Management: | Stock, tuned by Granatelli Motor Sports with EFI Live |
| Power Adder: | Granatelli Twin Turbo Kit with twin 76mm ball-bearing turbos |
| Maximum Boost: | 12psi |
| Intercooler: | Granatelli/TTI Mega-Cool with twin TTI induction fans |
| Exhaust System: | Granatelli exhaust with Corsa mufflers |
| Transmission: | G-Force T56 |
| Clutch: | Exedy carbon fiber |
| Driveshaft: | Stock |
| Front Suspension: | Stock |
| Rear Suspension: | Stock |
| Rear End: | Stock w/ Mark Williams halfshafts |
| Front Brakes: | Baer Extreme-Plus 6R w/ six-piston calipers |
| Rear Brakes: | Baer Extreme-Plus 6R w/ six-piston calipers |
| Wheels: | HREGranatelli Signature Series |
| Front Tires: | Michelin Pilot Sport 275/40ZR-19 |
| Rear Tires: | Michelin Pilot Sport 345/35ZR-19 |
| Fuel Octane: | 91 |
| Weight: | 3,125lbs |
| Best ET/MPH: | 9.76 at 154mph (spinning) |
| Best 60-ft.Time: | 1.41 |
| Current Mileage: | 824 |
| Miles per Week: | "Could be driven daily, but I just take people for rides." |