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
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Sibling Rivalry 1
Photo Dito Milian
Sibling Rivalry 2
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Sibling Rivalry 3
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Sibling Rivalry 4
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Sibling Rivalry 8
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Sibling Rivalry 9
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Sibling Rivalry 10
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Ray was also not entirely enamored of the Z07’s carbon-ceramic brakes. He found them to have plenty of stopping power, but did not like the pedal feel, which he found to be too soft. Though he didn’t encounter brake fade per se, he said he had to “double tap” the middle pedal coming into the circuit’s deep braking zones in order to regain a firm foothold on deceleration. This was a finding we hadn’t anticipated.

Next we ventured out in Ravel’s ZR1, still fitted with the Hoosiers. Within a few hundred yards, Ray remarked on how much more powerful the supercharged car felt. Even as he waited for the slicks to come up to temperature, Ray had little trouble dispensing with the other cars in the run group. Unfortunately, once the tires were warm and he began to carry more speed into the corners and brake harder, a wheel judder surfaced—one of the alloys was clearly out of balance. We pressed on for a few more laps, but ultimately cut the session short and came into the paddock.

There, Ray had a frank discussion with Ravel. Obviously, he conveyed the wheel-balance problem to the owner—of which he was already aware—but he also offered some feedback on the tires. “Richard, I honestly think you’d be better off with the Michelins,” said Ray. He explained that the sticky Hoosiers had made the suspension feel soft, creating a greater sense of body roll than he had experienced in his prior experience in a ZR1 with standard rubber. On went the production rolling stock.

With the circuit cleared of track-day participants and the corner workers and safety personnel willing to stick around an extra 20 minutes before starting their lunch break, we got down to the business of putting some numbers on the board. The idea was not to perform all-out qualifying laps, but rather to push both cars at an equally hard nine-tenths pace. Our priority was to establish the difference in lap times between the two Corvette models, not set any records. With that in mind, both cars would be driven with all driver aids defeated, the suspension set in Sport mode and sans passengers. Ray would drive each car four laps—an out lap, two timed laps and a cool-down lap. We admit that more laps would have been preferable, but in the interest of safety, tire life and the corner workers’ stomachs, this plan seemed prudent.

Ray buckled into the Z07 first and quickly streaked down pit lane to start his warm-up lap—there was no time to waste. From our vantage point on the start/finish line, we could see a good deal of each lap; thanks to the lack of vehicular traffic and the bypass flaps on the Z06’s exhaust system allowing the 7.0-liter V8 to bellow forth unmuffled, we could hear each lap in its entirety. The sense of anticipation was palpable as we waited to stop the watch on the first hot lap. When we did, 2:01.51 appeared on our screen. Proving we’d found the right man for the job, this was followed by a 2:01.53. Consistent speed was just what we wanted.

Ravel could hardly contain his excitement as Ray stormed out of the pits in his ZR1; when the 638-horsepower bolide rocketed past us down the straight he was bursting with joy. “Just listen to that engine!” he declared with justifiable pride. With a layer of high-pitched sophistication overlaying its ground-pounding bark, the ZR1 exhaust note is unique—the aural equivalent of an all-American linebacker that went to finishing school in Europe. It’s a glorious noise. Perhaps even more impressive was the speed the ZR1 carried down the straightaway leading to Turn 1; it was clearly going faster than the Z07. Most of the Corvette enthusiasts we polled at the track said the ZR1 would post a considerably quicker lap time than the Z07, and this display of sheer speed seemed to confirm their prediction.

Then we got our first ZR1 lap time: 2:01.14—a piddling four-tenths of a second faster. Surely, Ray must have had an off lap. This assumption was scuttled as soon as he flew past our timing station to complete his second flier. The time was 2:01.63, a tenth slower than the fastest Z07 time. It was a shocker. We had expected the naturally aspirated car to be close in pace to its supercharged sibling, but not this close.