The Toughest  Corvettes the ZR1 and the ZO6  Battle

  When you were growing up, the two kids who thought they were the baddest in town and they always had to fight to see who was the toughest. Then we grew up and bought Corvettes. First, from 1990 to 1995, there was the ZR1. And now the current "bad boy," the Z06, has come to the neighborhood.

  So here's what the Corvette world has been waiting for a showdown between the LT5 powered ZR1 and the new LS6 engined Z06, two of the toughest Corvettes ever produced. The outcome may surprise you.

  The ZR1, which was quickly dubbed the "King of the Hill" by owners, was a limited edition, rather expensive at $60,000 plus, C4 based Corvette, available from 1990 to 1995 and built to be the world's fastest production car at that time. The Lotus Chevrolet designed LT5 engine was based on the standard V8 engine, but it was topped off with 32 valve heads and four overhead camshafts. To this day, the 375 horsepower LT5 engine is one of the finest powerplants in the world, still holding some of the records it set in the early 1990s.

  The current Z06, on the other hand, is a more refined road car based on the lightweight C5 hardtop. Priced $20,000 less than ZR1's when they were new, the Z06 represents a true performance car bargain. Incorporating many enhancements over the standard C5 for a big difference in performance, the heart of the Z06 is its pushrod 5.7 liter LS6 powerplant, rated at 385 horsepower. Other major improvements come from the Tremec 6 speed M12 transmission, a trick titanium exhaust system for reduced weight, FE4 suspension package, new rear brakes, a Second Generation Active Handling System, and ten spoke aluminum wheels with Goodyear's Eagle F1 Tires. These all add up to better traction, improved handling, and more power to the ground, which could, which you might figure, offset the power advantage of the ZR1 in a head to head drag strip showdown.

  Finding a dead stock ZR1 for a shootout proved difficult. Seems like everyone who owns one of these rare beasts has performed some type of modifications from mild to wild.

   Even though there had been some mild aftermarket enhancements to the red 1991 ZR1, like a custom chip from Doug Rippie Motorsports, Borla Challenger cat back exhaust system, and dual K&N air filters, it was felt it was close enough to stock to accept the car for the shootout, especially when it was learned that the Z06 was also mildly modified.

  The ZO6 was blessed by being the recipient of the prototype for Corsa's titanium cat back exhaust system, plus the car is equipped with an LS1 PWRFLO Air Filter from Vinci Hi Performance.

  Roger Vinci, shared his feelings before and after the shootout. "Buzz and Harry brought their Corvettes to our shop and we dyno tested them both, optimizing everything so we knew we had a good baseline," said Roger. "Harry's ZR1 did have a horsepower and rpm advantage over Buzz's Z06, but that's an overhead cam engine verses a pushrod motor, so no surprises there."

  The rear wheel power figures from Vinci's DynoJet worked out to 347.8 horsepower with 336.3 ft/lbs of torque for the ZR1, and 340.2 horsepower with 337.7 ft/lbs. torque for the Z06. Very close indeed, especially on the torque side, but the drag strip would confirm which car could put the similar power numbers to the pavement better.

  The pair of Corvettes reconvened  at Bradenton Dragway in Bradenton, Florida, for the quartermile shootout portion of the test. The driver made several runs trying to get the best out of each car and finding their strengths and weakness.

  "What surprised me the most was how bad the ZR1 hooked up," the driver commented afterwards. "On each run, the rear end would break loose and pull to the right off the line. I got no weight transfer on the launch. But on the plus side, the LT5 engine had an rpm advantage at the top end, so I didn't have to shift from third to fourth gear, which saved a couple of tenths." The best elapsed time for the ZR1 was a 13.13 second at 110.33 mph, obtained on the drivers fifth pass down the quartermile.

The performance from the Z06 demonstrated the advancement Chevrolet has made over the last ten years of Corvette development. The driver needed only three runs in the Z06 to top the chart with the best of 12.89 seconds at 113.26 mph. Even though the ZR1 boasts slightly higher horsepower numbers on paper and on the DynoJet, it was the Z06's more refined suspension that made the big difference in the quartermile. "The Z06 hooked up so hard that the front end jumped straight up in the air," the driver said. "The weight transfer on the launch was vastly superior to the ZR1."

  So, basically, you could call it a tie. The ZR1 won the rear wheel horsepower portion of the test, while the Z06 came up the big winner on the quartermile.