Pontiac Bonneville Salt Flats Racer
From GM press: Pontiac, the excitement division of General Motors, updated its racing heritage at the famed Bonneville Salt Flats in Utah when a four-door Bonneville barreled through the timing traps at 202.524mph making it the first front wheel drive production car to exceed 200 miles per hour.
One of 355 entries during Speedweek, the Bonneville was driven by 30-year race veteran Mike Cook, a member of the Bonneville 200 mph club. Cook has set records at El Mirage and Muroc dry lakes, was confident in the Bonneville's ability to exceed 200mph, but knew the challenge lay in handling a front wheel drive production car.
"Because of the exceptional engineering that already exists in the Bonneville, the challenge lay with me to learn the nuances of front wheel drive at high speeds. The feedback was different than any other car I have ever driven," said Cook of the popular sedan. "Under normal driving conditions, the 3.8 V-6 engine can go from 0 to 60 mph in seven seconds. We started with a great product, which minimized modifications."
The Bonneville underwent a transformation from a family sedan to a high-speed performance machine at Cook Motorsports in Norco, Calif. Pontiac assembled a team of engineers and expert mechanics including Cook, Richard Lee, Jim Poplawski and Jan Callison to make the modifications.
The Spruce Green Bonneville retained much of its assembly-line amenities including the 12-disc CD changer, power windows and door locks, cruise control, keyless entry and alarm system. Confident of the car's ability, Cook played the radio during each run listening to KSALT 1610-AM, the voice of Speedweek.
The stock parts were joined with a few "race ready" revisions:
-A six-corner roll bar attached to the roof line and chassis, creating a roll cage to provide additional roof crush resistance for the driver in the event of a crash
-Jaz Products aluminum racing seats and covers in place of Bonneville's traditional bucket seats
-A Deist parachute, competition seat belts and fire protection system
-Custom-built "Intro" wheels, body lowered four-inches to reduce drag and lift
-Specially prepared transmission by Hydramatic Motorsports
The Bonneville's supercharged 3.8 liter V-6 engine, which uses a Kenne-Bell supercharger, was re-worked by Richard Lee of Lee Performance Products (LPP) and produced in excess of 600hp @ 6000rpm. Ported and polished cylinder heads have been re-worked by Morgan Engineering to substantially increase the power potential of the cylinder head. A special crank and rod preparation with balancing was performed by Evans Speed Equipment. Doug's Headers fabricated the custom exhaust system with thermal barrier coating applied by Engineered Applications. A LPP fabricated intercooler was added to the vehicle to pass cooler air from the supercharger to the engine. The 4T65E GM Powertrain transaxle was enhanced by Hydramatic Motorsports to run over 200 mph and the final drive ratio was changed to 2.56 from 2.93.
"This was an experiment to build horsepower reliability at an unknown level using mainly stock parts," noted engine builder Richard Lee. "What's more, we didn't have the luxury of using aftermarket parts during the development process."
GM Powertrain engineer Jim "Gabe" Poplawski provided critical engine calibration and developed a customized data acquisition program for the Bonneville. One of the major hurdles was determining the proper fuel supply for a racetrack located 4,260 feet above sea level. That number jumped to 7,100 corrected altitude when the 100 degree plus air temperatures were factored in.
"Modifying the production calibration and the computer controller from stock to race was a very complicated process," said Poplawski, "but we knew the L67 Bonneville platform was up to the challenge."
The Bonneville is the only American production car to earn, not be given, its racing name. The Pontiac Motor Division was established as a performance division largely in part because of its participation in runs at the Bonneville Salt Flats. In June of 1956, 73-year-old race car driver Ab Jenkins and his son Marvin co-drove a Pontiac Series 860 two-door sedan for a run that broke all existing American unlimited and Class C stock car records for a 24-hour world speed record of 118.375 mph. To commemorate the achievement, Pontiac named the Series 860 after the Bonneville Salt Flats.
The official recorded speeds for the cast iron, stock-block Pontiac dubbed "Spirit of Bonneville" were:
1st timed mile: 186.285 mph
2nd timed mile: 197.751mph
3rd timed mile: 202.524 mph
The Bonneville Nationals Inc. also employs a "terminal speed" clock to give racers an idea of the car's performance - whether it is slowing down or still accelerating. The Bonneville was clocked exiting the last timed mile at 204.087 mph which meant there was still more horsepower to be squeezed from the 2000 street legal, full-size luxury car.