The results were immediately noticed on the way back to the track. "Just when you think you're about to start driving a street-legal race car, you start to appreciate what the coilovers and sway bars have done to the car's feel. I always felt the Z06 handled incredibly, but now I realize how much room there was for improvement," opined Tanner.
Adding stiffer sway bars and springs typically has a negative effect on a car's ride characteristics, but that wasn't the case in this instance. Tanner told us that the improved damping and spring rates of the adjustable Pfadt coilovers helped the car stay comfortable without blunting its aggressiveness in turns-and the Porsche-killer setting is only an adjustment away.
There are 16 adjustment clicks built into the Pfadt coilovers; the company recommends starting by turning the knob counter clockwise until it stops, which is full soft. Adjustments are made from there and described by click count for consistent adjustments. For the street, Tanner set his at six clicks from full soft in the front and back.
"The 'six and six' adjustment will give a comfortable ride and increased performance. A lot of people use those settings for mostly street-driven cars and very limited track time, like Howard's car," said Aaron Pfadt, owner of the company that bears his name. We queried the suspension guru on what settings are needed to step things up a notch. "For the track, I recommend 10 clicks from soft in the front and 12 in the rear. That is a great starting point, and you can fine-tailor it from there," Pfadt said. "It stiffens up the dampening, and that is what plays a big role in stiffening the car. It won't be a harsh ride like a race car, but it does firm it up. Most people use that setting on the track, but we do have customers who run those settings on the street and don't mind it." The sway bars were set up to Pfadt's recommended settings, which are explained clearly in a comprehensive instruction manual.
On track, Tanner's initial assessment of better handling was confirmed as the twin-turbo Vette ran a new best two-lap run of 45.20 seconds (a 1.1-second gain) using the street-friendly six-click settings. We checked back with Tanner a few weeks after the on-track testing to see if he was still giddy about the new mods.
"The true test came when I really started pushing the car through the highway on-ramps in the past few weeks. I didn't feel any body roll, and the car felt predictable as I pushed it deep into the turns. Normally, hitting bumps in a turn with a Corvette can be a bit unnerving. The Pfadt true independent suspension, however, allows the car to hit the bump, and the three other wheels stay planted. The suspension mods not only increase the limits of the vehicle but also add control to make it easier to drive. It's very reassuring as a Vette owner."