People often say it's an addiction, modifying your car. "Mod Fever," they call it. And once you get a little taste of making that car just a bit better, more often than not, you're hooked.
The trap many fall into is going willy-nilly making the mods they can make, rather than the ones they should make. Instead of thoughtfully devising a plan of action, taking into consideration their ultimate goals, those who randomly bolt on parts because they're the latest rage or simply look cool often wind up with a car that performs the same as or-shudder-worse than it did before they screwed with it.
Steve Kepler is not among those who have fallen into the wholesale-modification trap. Much has been written of the C6 Z06's track prowess, and according to Kepler, it's all true. "There really isn't much this car needs to run hard at the track all day," the Waukesha, Wisconsin, resident explains. Having taken delivery of a factory-fresh black C6Z in March 2006, Kepler was no doubt tempted to whip out the credit card and start throwing parts at it. Instead, the sales rep for Johnson Controls (the parent company of Optima Batteries) patiently got to know his car, putting it through its paces at nearby Road America, evaluating its strengths and making note of its weaknesses. Soon, a plan came into focus.
Grunt is one thing the LS7 has in spades, but even so Kepler couldn't ignore the relatively simple power gains to be found in easing its breathing. The addition of a K&N air filter was an obvious choice. The wealth of aftermarket options for exhaust components made the job of choosing those pieces far less straightforward. After some research, Kepler selected a pair of American Racing's stainless-steel headers and teamed them up with a Magnaflow exhaust system. "The headers were installed by my local Dealer, Andrew Chevrolet, in May 2009. They fit perfectly and, along with the Magnaflows, sound great. The installer noted that these were the best-fitting headers he had ever installed. I agree that the form, fit, and function are perfect," Kepler says.
While the intake and exhaust changes made a positive impact on Kepler's ownership experience, it soon came time for him to turn his attention to more pressing matters-namely the braking system. While the motoring press (and, indeed, most owners) claim the big, upgraded brakes of the Z06 are more than up to the task of slowing the car, those who exercise theirs on-track know better. "The OE brakes change shape when run at high speed and the heavy braking that accompanies it, such as at Road America," Kepler says. Hard-core Z06 track rats know that this deformation leads to tapered pads and all sorts of attendant braking woes. The only real solution is an upgrade.
"The StopTech brakes were installed in September 2007 so we could test them in the Silver State 0-100-0 competition. The StopTech group showed great support by flying the brakes to us in Las Vegas, and we installed them in the parking lot at Sam's Town in a few hours," Kepler says. The install was completed just in time to hustle the car to Ely for the event. "We won and had the shortest overall distance." Kepler's Z completed the 0-100-0 run in just 11 seconds, covering only 1,218 feet in the process and generating 1.42 g's of deceleration force. "Needless to say, the brakes' performance has far exceeded my expectations." Kepler was also Sixth in the Silver State's 2007 standing-mile competition, with a top speed of 163 mph. The following year, with his younger brother, Mike, co-driving, Kepler won the 145-mph class at the Silver State with an average speed of 144.9986 mph.
With both the go and whoa addressed, Kepler next focused his attention to maximizing cornering traction. For this, he turned to Pfadt Race Engineering. Pfadt recommended a set of its adjustable coilover shocks, which feature 16 different damping settings that are easily adjustable. The shocks' threaded bodies allow the user to make ride-height adjustments independent of spring preload. To give the car a crisp feel with decreased body roll, a pair of Pfadt sway bars feature torsional stiffness nearly three times that of the stock C6Z bars. In order for the car's balance to be tuned, the Pfadt sway bars are rate-adjustable. Lastly, the sloppy rubber suspension bushings were replaced with Pfadt's polyurethane/aluminum units.