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Showcase cover image for 1990 ZR-1

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Fully optioned
1990 ZR-1 debut and off to my Corvette dealer's Showroom floor. the $68+k marked up a bit over $100k, with custom rims added on. After 13 yrs. of buying yearly for myself and friends, this was the first time my dealer refused a Corvette sale at MSRP. At the end of the year, unsold (kept on the showroom floor as a marketing attraction to draw non-ZR-1 buyers in), my usual salesman calls and asked if I'm still interested at MSRP: "Sure.. put the OEM rims back on and I'll be right down...".
The '90 ZR-1 broke the "Mormon Meteor" 50 yr. 24hr. endurance record, doing 175.885 mph, in virtual stock setup, 70% throttle stop, with only a radiator hose replacement during the effort:

Corvette Chief Dave McLellan with Lotus designed the ‘90 ZR-1, powered by a DOHC, all-aluminum, twin overhead cam, 385/405-horsepower LT5 engine (basically a ‘80's Indy car engine), with an improved suspension and special wide body ($27,016 option),

In the summer of ‘89, Peter Mills (PR) and Stu Hayner (racer) focused on the current speed records for IMSA GTP. 962 Porsche failing break Ab Jenkins 1940, 24-hour speed record of 161.180-mph with the “Mormon Meteor”, Duesenberg, with a 1570-cid Curtiss aircraft engine. Hayner talked with Chevy’s John Heinricy who pitched the idea to Corvette chief engineer Dave McLellan. Tommy Morrison was brought on board with sponsor’s Mobil Oil, EDS (Electronic Data Systems) and Goodyear. Team members included Corvette Challenge driver, Scott Lagasse, Corvette Group Engineers Jim Minneker and Scott Allman; Showroom Stock racers Don Knowles and Kim Baker.

The search for location discounted Daytona and Talladega due to the expense and high banks that seriously load suspension of the basically stock ZR-1. The Nissan track in Arizona declined to host. GM’s 5 mile Proving Ground could not meet safety concerns. Bridgestone’s Tire Proving Ground, Fort Stockton, Texas, with a 7.71-mile oval/7 degree gentle banking (engineers calculated a 190-mph, cornering g-force at 0.5-g), was chosen by Morrison.

Bridgestone’s track included 1.5-mile long straights, 2.35-mile curves, 3 lanes, that allowed the car to be driven nearly flat-out with a clear focus and steel nerves (no guardrails, or barrier fencing to keep animals out, requiring anti-animal whistles and seven pairs of men spaced about a mile apart outside the track, using shotgun blasts).

Jenkins’Duesenberg was an all-out, purpose-built racer, The ZR-1 was essentially stock with minor racing hardware and full-out safety equipment, going into service by GM-Europe for record runs, and were built in late 1989, early 1990. Modifications included full roll cage, a 45-gallon fuel cell, suspension (stock lowered in the front), rear anti-roll bar was removed (room for the fuel cell), and a 3.07:1 rear gear. For night racing, the stock headlights, fog lights, and turn signals were replaced with racing lights and two aircraft landing lights mounted at the front license plate mounting. Extra oil coolers and differential coolers were added, and the side view mirrors were removed. The Dymag magnesium racing wheels were fitted with special-made, experimental radial tires from Goodyear (25.5×12.0-17's), with $250,000, in development costs.
The front air dam was enlarged and reinforced and fitted with special ultrasonic anti-animal whistles. The passenger seat was removed and replaced with the EDS telemetry system for constant data monitoring and driver communication. John Heinricy: “We did everything we could to mitigate risk. We calculated g-levels we’d be running. Calculated tire loads, We ran tests on the tires. They x-rayed every tire. There was nothing to break as the car wasn’t that stressed. The engine was run hard, but not as hard as we ran them on the dynamometer.”

Per FIA rules re: “non-consumable” spare parts, the ZR-1 carried 300-pounds of spare parts in two suit cases attached to the rear roll bar. Drivers had to be able to fix the car if unable to return to the pits.

The Mercury Marine LT5 engine was directly off the assembly line, essentially stock. The engine had a minor balance problem and was shipped directly to Morrison, who fixed the issue and with headers, open exhaust and controls calibrated for racing fuel. Horsepower stood at 400 - 410. The calculated 190mph needed to break the speed record required 5500rpm in 5th gear, with the throttle stopped at 70%.

The full team included the drivers, the Morrison Development team, GM, EDS, and STG technicians, engineers from Goodyear, agents of associated sponsors, GM public relations, and USAC (United States Auto Club) to officiate the FIA record attempt.

The 8 drivers (80 minute rotations) included: John Heinricy (1989 SCCA Escort Champion and Manager of Corvette Development), Tommy Morrison (owner of Morrison Motorsports), Corvette Group Engineers Scott Allman and Jim Minneker, Showroom Stock racers Don Knowles and Kim Baker, Corvette Challenge racer Scott Lagasse, and Stu Hayner.

The timed event started at 9:55:12am on March 1, 1990 with Heinricy: “Speed was in the low 190s. We didn’t lift in the turns. We entered them foot on the floor and by the time we came out of it, we’d be in the high-170s. It didn’t slow down much in the turns.” Fuel stops only took about 45-seconds to fill the 48-gallon fuel cell. The chassis and tires weren’t stressed due to the .5G low cornering loads. Weather included cold, windy, overcast, light drizzle, patchy fog, and snow flurries.
The open track included a coyote over the outside into Hayner’s lane, which stopped, looked and retreated back. Birds on the track at 200mph “vaporize.”, usually unseen, just a bang on the windshield. Heinricy hit two or three. New Moon on March 1st (no moonlight on the unlit track), the ZR-1 was clearly over-driving its lights. Heinricy, as to any incidents, and potential for flying off the track: “I was still pretty young, then. I think some of us were thinking: it wouldn’t happen to us. That’s the mentality of most race drivers.” The only nighttime issue was a tire sensor counter-weight coming off, the vibration broke off Minneker’s radio microphone wire, requiring a quick pit stop and a tire change.

The ZR-1 the team decided to go for the 5000 mile record, driving for another four hours. With eight laps left, Hayner pitted as due to the engine seriously overheating. The radiator shroud had been rubbing on the water hose, causing a loss of cooling fluid. The hose replaced, Hayner finished the final eight laps, last lap at only 140-mph. The ZR-1 completed 5000 miles in 28-hours, 46-minutes, and 12.426-seconds. Stu unscrewed the 70% throttle stop and took two hot laps at full-throttle, 15-miles at 190-plus. The entire effort was about breaking a long-standing speed, endurance, and distance records. At the end of the experience, the team racked up the following records;

5000 Kilometers at 175.710-mph
24-Hours at 175.885-mph
5000 Miles at 173.791-mph
Plus, four FIA International Category Class A-G2-C10

After the event, the entire team signed the underside of the hood. The ZR-1 was cleaned up and went out on a promotional tour as the “World Speed Record ZR-1 Corvette.”

The Corvette's record, set on March 2, 1990, stood for eleven years, seven months and 12 days.

*Credit here goes to automotive writer Hib Halverson, the only reporter to be allowed to attend the event, who just happens to live 2 miles away from me, a very cool Corvette GURU, lug nut, and had a purple ZR-1 named “Barney”, only 1 of 25, owned by GM, delivered to Chevrolet Public Relations, obtained by Hib.