Chevrolet Corvette ZR1 - Corvette Legends

The Last ZR-1 In Pro Racing.

Hib Halverson Jan 5, 2010 0 Comment(s)
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The '99 season ended with Cooper fifth in points-the best of the Corvettes, but a Viper, a pair of Porsches and a Toyota Supra did better. More coulda-woulda-shoulda? Cooper's fifth-place points finish came in part because tough old #75 took him to a pair of seconds, a third, and a fourth. Had it not been for overstressed stock cam chains, the outcome woulda surely been different.

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Driving the Phoenix When the oil temperature reached 150 degrees Fahrenheit, I whacked the throttle a couple times.

Whummba! Whaauuummmmmbababa!

Oh, I'm gonna like this a lot, I thought. I pushed the ZF six-speed into first, gave the motor some gas, and let out the clutch.

For my test, the Phoenix was still running the not-so-radical cams installed for the Monterey event. Two Mercruiser employees, Scott Skinner and Greg VanDeventer, both of whom once worked on the LT5 program and now moonlight doing racing LT5s, built this engine and the "full-on" motor that did so well at Atlanta. The stock LT5 camshafts were forced on the team by a lack of LT5 cam "blanks" on which racing cam profiles can be ground. The last of the Pirates' good cams were in the engine they broke at Trois-Rivieres.

"Only" 520hp would still be more than adequate, considering the car's weight and my lack of experience driving it. The engine with stock cams was only a little more powerful than the LT5 in our "Purple Project" car which, coincidentally, was also done by Skinner and VanDeventer. That realization comforted me a bit as I entered the front straight and went up through the gears.

Stopping power is something the Pirate Racing ZR-1 does not lack. Less weight than a stocker along with Brembo four-piston calipers grabbing 13-inch cross-drilled rotors up front and production '96 Grand Sport front brakes on the rear means, when you stomp on the brakes, you slow down-right now.

Even with 25 more horsepower, 4.09:1 gears, and 2,800 pounds, this car didn't feel much quicker than our project ZR-1 below 4,000 rpm, perhaps because: 1) the race motor has no secondary port throttles, which reduces torque below 3,500 rpm and 2) its heads are ported to beat hell. The solution? Well, duh-don't run the engine down low.

No port throttles, radical heads, headers, and no catalytic converters make the power disparity between #75 and our project car quite noticeable above 5,000 rpm. Not only is there more power, but the race engine peaks near 7,000 rpm, whereas the motor in the project car peaks at 6,500. In first and second gear #75 blows the tires away easily.

Tires proved to be the Phoenix's weakness in my brief drive. While the car's handling was pretty good considering it was set up for another track, the set of BFG g-Forces on the car were a little used up. That had me sliding around a bit out there.

The creature comforts in the Pirate Corvette, even for a race car, were pretty crude. No wonder it's called the "Bitch." The pedals were angled wrong to the driver, were too close together, and there was no dead pedal. Fixing that stuff would make the car easier to drive, but, as JVD told us, "That kind of thing isn't high on our priority list. Also, Coop doesn't care much about creature comforts. He just wants to win."

Maybe so, but we think it's a good thing the '99 World Challenge had no endurance races. Another race car quirk was the Lexan windshield. Lexan is great for light weight and to meet safety rules, but talk about waves and distortion. That, coupled with the front sections of the rollcage restricting the driver's view, made vision to the sides of the track difficult. Again, this is a case in which the car's regular driver would have an edge through experience, whereas I had trouble picking out apexes through the distorted Lexan. So, not only must Cooper never suffer back pain or leg cramps during a race, but he turns-in by ESP because he sure can't see anything through that blurry Lexan.

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