It takes quite a car to catch a magazine editor’s eye, but this one did just that at 2010’s Corvettes at Carlisle. But unlike many of the restored and modified Vettes that were on hand, much of this one’s conversion was done by its owner—in his garage.

John Callahan bought this ’07 coupe new at Kerbeck’s in Atlantic City, New Jersey, in September 2006, but it wasn’t his first Corvette, or even the first in his family. He’d owned an ’87 and a ’95 before this one, and his brother-in-law, Jim Uriah, had a ’99 fixed-roof coupe with a ProCharger and CCW wheels.

That fixed-roof C5 got Callahan thinking about his C6—and, eventually, upgrading it. “It started out as me just wanting the rear wide-body kit,” he says. “The more I got into it, the more it happened that way.” And the more the upgrades came to mind.

His first one: a supercharger. “The reason I did it was because my brother-in-law had his,” says Callahan. “When he got his ’99, the first thing he did was put a supercharger on it. That’s why I’d always wanted one—because I’d seen what his car did.”

Unlike the ProCharger on Uriah’s ’99, this Vette received a polished Paxton Novi 1200 with an East Coast Supercharging methanol kit. On top of his otherwise-stock ’07 LS2, the Novi bumps output up to 711.4 rwhp and 646 lb-ft of torque.

To complement his polished power adder, Callahan dressed up the engine bay with chrome replacements for the coil, fuse box, master cylinder, and power-steering-fluid reservoirs, as well as the dipstick.

The only other change he made to the powertrain was a B&M shifter replacing the stock one. Other than that, it has the same six-speed MN6 transaxle and 3.42 final-drive gearing that went in at Bowling Green.

The exterior of Callahan’s ’07 is another matter. “I just like the look of the ZR1,” he says, which was reason enough to make his ’07 look like one.

Instead of trusting the conversion work to an outside shop, Callahan chose one closer to home. “I did it in my garage,” he says of the changeover, ably assisted by his local painter, Jeff Bong. “I’d take one piece to Jeff and he’d paint it, then I’d bring it back home and take another one to Jeff, and he’d paint that.”

After Bong did the paintwork, Callahan installed the ZR1 pieces himself. “Most people don’t believe I did that in my garage, because I replaced every single panel on the car except for the doors, rockers, and hatch,” he says, adding that those parts that stayed on were painted at Bong’s shop. “Everything else is a GM carbon-fiber part for the ZR1.

Inside, along with the B&M shifter, Callahan added a Pioneer CD/DVD sound and video system, plus carbon-fiber accent pieces all around the cockpit. But Callahan has some future plans for inside.“I’m going to do a Down South Vettes interior,” he says. “I’m planning on doing the steering wheel and the seats.

With an engine whose output has been boosted from less than 400 horses to more than 700 (711.4, per the dyno), you can guess what this car is like to drive.

“It’s very fast!” says Callahan with a big laugh. “I went from having 383 horsepower to 711. It took a lot of getting used to.” Even with all that power on tap, Callahan says that his ’07 still runs like a stock LS2-powered Corvette while highway cruising.

Callahan’s best time in the quarter-mile is 11.96 seconds at 119 mph, which he says was run with just a tune and headers. He hasn’t had it down the track since the blower install.

“That’s because it turned out so good that I’m scared I’ll break something,” he says. “I really don’t want to beat it now.” Another reason: Having a car that quick takes the fun out of the track-day trips with his buddies who have stock (or close to it) Corvettes. (That, and needing to install a full rollcage if he runs a sub-11-second pass on many tracks.)

But that doesn’t mean he won’t air it out occasionally. “I’m going to run it someday, just to see what it can do, but I don’t know how soon,” Callahan says. “I know that I’m not going to be able to go all out. I have Drag Radials for it, but I don’t think that I’ll break anything with them on, because they’ll spin first.”

One place that Callahan took his Corvette was last year’s Corvettes at Carlisle show. That’s where Editor Heath saw it and made it his “Celebrity Choice” winner.

Not bad for a car inspired by a brother-in-law’s Corvette...and built in the owner’s garage!

Spec Sheet: ’07 Coupe
OwnerJohn Callahan; Allentown, Pennsylvania
BlockStock LS2 aluminum
Displacement364 ci
Compression Ratio10.9:1
HeadsStock LS2 aluminum
ValvesStock 2.00/1.55
CamshaftStock hydraulic roller
Rocker ArmsStock 1.7 ratio
PistonsStock hypereutectic
CrankshaftStock nodular iron
RodsStock cast
Intake ManifoldPorted stock
Power AdderPaxton NOVI 1200 supercharger with ECS methanol kit, 13 psi boost (max)
Fuel Injectors60-lb/hr
Fuel PumpStock with Kenne Bell Boost-a-Pump
IgnitionStock coil-on-plug
Exhaust System1 3/4-in American Racing headers, Billy Boat “Bullet” exhaust
TransmissionStock six-speed manual
SuspensionStock Z51
RearendStock with 3.42 gears
BrakesStock Z51 with nickel-plated rotors and red powdercoated calipers
WheelsD2 Forged VS1 chrome; 20x10-in front, 20x12.5-in rear
TiresNitto Invo; 285/25ZR20 front, 345/25ZR10 rear
Fuel Octane93
Weight3,300 lbs with driver
Best ET/MPH11.96 sec at 119 mph (NA)
Best 60-ft. Time1.70 sec
Current MileageAbout 20,000
  • «
  • |
  • 1
  • |
  • 2
  • |
  • View Full Article