Bonneville punishes power with heat and altitude. Thin, hot air costs density, and density costs horsepower. On this 1989 GMC S-15 record truck, the answer was a 5.0-liter version of the stock-block 4.3L V6 backed by a chilled water air induction system that cut inlet air temperature by about 40 degrees. That gave the engine a denser air charge without forced induction, helping it hold power through the run in brutal salt-flat conditions. With full instrumentation, radio-linked data acquisition, and Banks Engineering managing the record-setting effort, the truck went out and proved the point: five records, capped by an FIA International World Speed Record of 194 MPH.
At Bonneville, the salt bed of a prehistoric lake, GMC Truck pursued FIA land speed records with a specially prepared S-15 Club Coupe. The program targeted two records for production-body vehicles with engines displacing 5 liters or less. In FIA Category E, a Jeep pickup held the two-way average record through the flying mile at 141.381 mph. In FIA Category A, Porsche held the corresponding two-way average record with a 928 at 171.110 mph through the flying mile.
The truck began with a stock-block 4.3-liter V6. GMC's Advanced Vehicle Engineering department had K-Tech of Mount Clemens, Michigan enlarge the engine to 5 liters. In that form, the engine produced 523 horsepower at 6,800 rpm, giving the compact pickup the output needed for a serious Bonneville record attempt.
Bonneville's conditions imposed major performance penalties, with temperatures near 100 degrees and elevation around 4,200 feet. To offset the loss in air density, the truck used a unique chilled-water air induction system. That system reduced inlet air temperature by approximately 40 degrees, helping preserve engine performance in the hot, high-altitude environment.
Truck and Bus Engineering's Advanced Vehicle Engineering department fully instrumented the GMC S-15 Club Coupe for the record runs. Vehicle data was transmitted by radio link to dedicated data-acquisition equipment installed in a motorhome positioned trackside. Engineers monitored the performance of all systems during each attempt, and the information was stored for review after every run.
For visual documentation, GMC equipped the truck with two onboard TV cameras. One camera looked directly through the windshield, while the other was aimed at the driver and the instrument panel. Both cameras operated during all record attempts so the team could correlate vehicle behavior, driver inputs, and instrument readings with the recorded engineering data.
The S-15 was also prepared with substantial safety equipment for high-speed operation on the salt. A Recaro racing seat was installed for driver support and restraint. The truck also received a full roll cage and fire bottles to improve protection during the record-setting runs.
Management of the record attempts was handled for GMC Truck and the Advanced Vehicle Engineering section of Truck and Bus Engineering by Banks Engineering of Los Angeles, California. As the team completed the truck's final inspection, the effort moved from engineering preparation to execution at the course.
With the GMC given a final once-over, driver Don Stringfellow prepared for the run. Stringfellow, a member of the Bonneville 200 Mile Per Hour Club, suited up in his Nomex fire-retardant gear before taking the truck out for its record attempts on the salt.