In many ways, Robert Zona is a very typical Corvette owner. When he purchased his new 2003 Chevy Corvette Z06, he thought it would be a great toy for weekend cruising. Though it was his first six-speed performance vehicle, he quickly became addicted to the satisfaction that only comes from rowing your own gears.
It wasn't long after that the 39-year-old dentist from Jackson, New Jersey, found himself at the dragstrip in nearby Englishtown for a show-n-go event. "I had never drag raced before, but I decided to make a few passes. After that, I was hooked."
What makes Zona unusual, then, is that he now finds himself the owner of what may be the quickest naturally aspirated C5 in existence. "[My] 9.932 at 138.80 mph is currently the fastest NA e.t. ever recorded on the forums for a C5, regardless of engine size." While it may be going too far to say reaching this remarkable level of performance was like pulling teeth, it certainly didn't come without substantial effort.
What's it take to make a C5 run in the 9s? The most obvious answer, naturally, is brute power. For this, Zona turned to the pros at Anger Management Racing, in Brick, New Jersey. Though the original 346ci LS6 is still in place, don't make the mistake of assuming it's stock. While the short-block is mostly factory issue, with the exception of fly-cut pistons for valve clearance and a host of ARP fasteners for durability, it's the attention paid to the top end that makes the magic happen.
The rest of the car was put together by Zona and Tommy Michalkowski in Zona's garage. According to Zona, "One of the most rewarding parts of the build was that Tommy encouraged a lot of input from me." Together, they bolted on a pair of TEA-ported heads, a FAST intake manifold, a custom-spec cam, American Racing headers, and a GHL exhaust system. Nothing extraordinary jumps out at you when reviewing the buildsheet, but the combination of parts, and the attention to detail when assembling them, are a big part of what makes this car so special.
Once assembled, the car was handed over to Troy Nikola of Anger Management, who began the long process of tuning it to perfection. "I spent a lot of time with Tommy and Troy, dialing in this car over the past year. [It] was a process that we built upon from each previous track experience," says Zona. "Our first time out in the spring of 2008, the car trapped 134.40 in average air. So we knew it was going to put up some big numbers once the combination was perfected.
"Since we knew what the car was capable of, our eventual goal was to run 9s. Through the summer we dialed in the car, knowing that the cold air would bring faster times. Thanks to the help of the AMR crew, we were able to run our first 9-second pass in October 2008 and shock everyone with a 138.80 mph. We were able to back up the time and mph many times and managed a total of three 9-second passes, with a best of 9.93." This, of course, brought out the skeptics.
As with any groundbreaking endeavor, Zona and crew had to tolerate the cries of foul from the nonbelievers. "Since we dealt with a lot of crap from people who couldn't understand how we ran the numbers, we thought about doing a teardown at the track." Immediately after the 9.93 pass, the intake portion of the Z06's engine was disassembled to prove that there was no nitrous-oxide system in place. "The manifold and the Vararam, air bridge, and throttle body were completely removed from the car, proving there was no way any nitrous could have been injected into the car to boost performance." Further infuriating the doubters, the car was even driven to the track, raced, and then driven home after the teardown.
Weight and aerodynamics are also key considerations when attempting to maximize the performance of a car. Weight savings were realized in part by removing the passenger seat, replacing the hood with a carbon-fiber piece from Motor City Molds, and swapping the stock wheels for a big-n-little combination of Bogart D-10s. The Z06's inherent lightness, combined with some intelligent choices in equipment selection, have brought the car's race weight to just 3,188 pounds, with driver.
Despite its age, the C5 is a very aerodynamically efficient car, with a coefficient of drag of just 0.29 cd. Even though the Z06's hardtop body design is slightly less aerodynamic than the coupe's, that fundamental efficiency is still present, and it lessens the workload as the car approaches the top end of the track, helping make those eye-popping trap speeds possible.
Driving is another area that is frequently overlooked when seeking maximum dragstrip performance. For the past four years or so, Zona has coached many fellow Corvette drivers both on Internet forums and at the track, helping them to better their own performances. "The person who gave me the most help and advice when I first started out was John Armstrong (a.k.a. Ranger on the forums), who has helped hundreds of Corvette drivers over the years. I typically launch the car between 5,500 and 6,500 rpm, depending on conditions. The two-step makes the car more consistent on the launch, but it does take away some of the feel and driver input that could result in a slightly better 60-foot time."
Zona is enthusiastic about helping others maximize their driving and offers the following advice: "I always tell people to do a full burnout. With drag radials, I am able to run the tire pressure at around 20 psi, which makes the car very stable, especially on the big end. I shift the car over 7,000 rpm and power shift when the conditions are right, or if I want to maximize e.t. on a good air day."
Not content to rest on their laurels, Zona and the AMR crew plan to continue improving the combination. "We can see this car running 9.7s at 140 mph with some more minor tweaks and modifications." Naturally, the plan is to accomplish this with the same little 346-and no power adders.
And since the car still handles as well as most Corvettes, Zona has an eye on the twisties for the future. "With some minor changes, I plan to get involved in some road racing." And when he does, the competition had best be on their toes, because given Rob Zona's knack for meticulous preparation, this Z is likely to dominate the corners, too.
Editor's note: Since this story was written, Zona has replaced the LS6 with a 388ci stroker engine and run a best e.t. of 9.3 seconds-still with no power adder.