An old maxim goes, "If just enough is almost right, even more is better." For some Vette owners, that applies to their engine's output, as they seek more power and torque for quicker elapsed times and higher speeds on the dragstrip.
You can count Charlie Johnson among that group. His '05 Corvette, which came from Bowling Green with a 6.0L, 400hp LS2, now sports a 7.0L LS7 that's been ProCharged and otherwise modified to send the horsepower and torque numbers over 700.
But we're getting ahead of the story.Charlie bought this car at the outset of the sixth-generation Corvette's production run, and for a very special reason. "I was in the hospital for a month, and I told myself, 'If I get through all these operations and stuff, I'm going right to the Chevy dealership. If my wheelchair fits in the car, I'm going home in a brand-new Corvette.' That was my gift to myself, for getting through all the surgeries."
He found this black, automatic-equipped coupe and had it fitted for full hand controls so he could steer with his right hand while working the throttle and brake with his left. Otherwise, his C6 was factory stock. But not for long. "I drove it stock for less than a month," Charlie says. "I got bored with it. I ordered a ProCharger, and once I got it and felt the power it produced, I said, 'You know what? I want to go faster!'"
Mack Performance in Hialeah, Florida, installed the ProCharger, which turned out to be a pioneering job. As Charlie explains, "Mack Performance had a connection with ProCharger, and I was one of the first three guys to get one on the East Coast back then. I was the first guy with an '05 Corvette with a ProCharger here in Florida."
Once installed and dialed in, the ProCharger bumped the LS2's output by over 100 hp. "When Willie had everything done to it, it was pumping out 520 rear-wheel horsepower," Charlie says. "He did a nice little tune to it, and I was ecstatic."
That force-fed LS2 turned Charlie's Vette into an 11-second car that pulled away from his competitors. But eventually, Charlie wanted even more from his C6. "As I saw more people driving 11-second cars, I wasn't happy being 'average' again. I wanted to dip into the 9s. I want to run a 9.90 in street trim."
A four-point G-Force safety harness holds Charlie in at speed.
His dream was a car he could drive to the track with the air conditioner on, run 9.90s, then drive home, without any tire changing or trackside thrashing. That meant some major changes were in store for his C6.
Charlie's power addition began with subtraction. "I ripped out the original engine and ProCharger and sold them on eBay," he says. "I then had Horsepower Sales in Pompano Beach drop in an LS7 crate engine that I bought from Texas Speed & Performance." But that wasn't all. Far from it. "I then went from a P-series ProCharger to an F1A one," he says. "Usually, people go to an E-series one, but I went more extreme." He told his installers, "Let's put the bigger ProCharger on it. This way, if I run 9.90s and I get bored again, I'll at least have the supercharger that I can use to get the car into the low 9s."
Charlie's C6 then went to Next Level Performance in Altamonte Springs, Florida, as a friend recommended Geoff Skorupa's tuning skills once the LS7 and new ProCharger were in. "He fine-tuned it, straightened out all the bugs, and he got that car so it could run 9.80s-9.90s," says Charlie. "He also put a widebody kit on, a bigger brake system, a new driveshaft, and he put on stickier tires in back."
The need for stickier tires-Hoosiers, in Charlie's case-came as a result of the dyno numbers his car was now putting up. "On the dyno, Geoff tuned it to 757 rear-wheel horsepower," says Charlie. "That's when you need every little bit of traction that you can get."