Sibling Rivalry

Also from Issue 63

  • Katech-tuned C6 Z06
  • Best Corvettes for $12K
  • 1957 Roadster
  • 800-bhp C5 Convertible
  • Tech: LS Strengthening
  • 1967 Coupe
  • Driver Training
  • 1969 Coupe
  • Race Report: Petit Le Mans
  • How-To: Radiator Removal
Buy Corvette_magazine-63-cover
Sibling Rivalry 1
Photo Dito Milian
Sibling Rivalry 2
Photo Dito Milian
Sibling Rivalry 3
Photo Eric Gustafson
Sibling Rivalry 4
Photo Eric Gustafson
Sibling Rivalry 5
Photo Eric Gustafson
Sibling Rivalry 6
Photo Dito Milian
Sibling Rivalry 7
Photo Eric Gustafson
Sibling Rivalry 8
Photo Eric Gustafson
Sibling Rivalry 9
Photo Eric Gustafson
Sibling Rivalry 10
Photo Dito Milian

On the drive up from San Francisco, we quickly came to appreciate the Z07 package’s Magnetic Ride shocks. Set in Touring mode, they seemed to offer a smoother ride than the last Z06 we drove—this despite the shorter sidewalls of the ZR1-spec tires. While its ride quality doesn’t suddenly become Cadillac smooth with the addition of these dampers, the Z06 didn’t seem to protest as much over sharp jolts, such as expansion joints on bridges. Add this quality to the Z06’s low-rpm gait in sixth gear, comfortable seats and excellent ergonomics, and you have yourself a great freeway-cruising machine. The fact that we were getting mileage readings in the upper 20s was an added bonus. The only flies in the highway ointment were the tires’ tendency to tramline, which requires the driver to be at the ready with corrective lock, and tire noise. Perhaps it was the absence of wind and engine noise, but these Michelins were fairly loud.

Our three-hour transit to Willows also provided us some time to reacquaint ourselves with the Z06’s engine. We love the LS7’s slightly lumpy idle; it has the racy, high-compression-ratio sound of an engine born to rev. And rev it does. While its 427 cubic inches of displacement give it plenty of torque down low, the LS7 really comes alive at around 4,000 rpm, at which point it slams the Corvette forward with a ferocity we always find thrilling. It may have big-block size, but there’s no mistaking the LS7 for the small-block V8 it is when you get the tach swinging. Its intense rush to redline is accompanied by the sharply focused whine of a pure-bred race motor.

The flipside of all this exhilaration is an engine than can feel a little peaky at times, especially when cruising at freeway speeds. It takes a downshift or two to wake the LS7 from its 1,800-rpm slumber. To be fair, the tall gearing of its 6-speed manual transmission shares much, if not most, of the culpability in this regard. Unless you’re already humming along in the triple digits, sixth gear is not a passing gear. Don’t get us wrong, the Tremec box is a joy to row; that’s not the issue. The real problem is the ZR1. Once you’ve experienced the incredible flexibility of the supercharged LS9, everything else feels peaky. It doesn’t matter what gear you’re in with the ZR1, mind-warping acceleration is just a tip of the toe way.

Speaking of the ZR1, once we arrived at Thunderhill, we proceeded to search for a 2010 Cyber Gray model in the paddock. We knew we’d found the right one—yes, there was more than one ZR1 in attendance at this track day—when we eyed its CCW wheels and Hoosier slick tires; the “Ravel Racing” logo on the side of his trailer helped, too. Ravel had decided to get his laps in first, and he prefers to run race rubber when out on the track. We would switch back to the stock wheels and tires when we did our timed laps. This would occur during the event’s lunch break, when we’d have the 3.0-mile, 15-turn road course to ourselves. Before that, we’d run a 20-minute session in each Corvette, allowing us to get acquainted with its on-track characteristics. Our designated driver was David Ray. An experienced road racer, Ray is also intimately familiar with the C6 Corvette, having owned and track-driven a Z51-equipped coupe and already piloted a ZR1 around Thunderhill.

We headed out in the Z07 first. After a moderately paced initial lap, Ray began to bring the Corvette up to speed. Right off the bat he was impressed with the car’s front-end grip. “It really has a nice bite,” he said. “The car does not push! This is extremely rare for a street car.” Not only did the rear end also have plenty of grip, the car exhibited no problems in terms of traction out of the track’s slower corners. “I’m able to use all the power,” Ray yelled over the roar of the LS7 as we streaked off to the next corner.

We started off the session with the suspension set in Touring mode. After switching to Sport, Ray commented, “It has a little less body roll, but it was pretty damn good in Touring.” The difference between the settings was less dramatic than we had anticipated.

Overall, Ray found the Z07 to be “very friendly and forgiving.” He encountered only one problem area on the track, Turn 7. Usually he is flat-out through this high-speed corner, but the bend’s slight undulation combined with the Corvette’s high entry speed forced him to lift. “It got a little unsettled there,” he said afterward.

Connect with Corvette Magazine:   Facebook