The BME Bulletin #1
Bill Miller Engineering's Top Fuel
Blog A SUPERCHARGED EXPERIENCE Two key elements are responsible for the stunning performance of a Top Fuel dragster: nitromethane fuel and a powerful supercharger. The NHRA rulebook sets the limit on nitromethane at 85 percent and specifies the design features of the belt-driven blowers used in Top Fuel. But Bill Miller seldom follows the crowd and his determination to further develop his Gibson-Miller Supercharger is a case in point. The BME Okuma/Red Line Oil Top Fuel team's results in NHRA POWERade Drag Racing Series events held in Pomona, Phoenix and Houston reflected Miller's quest to build a better blower. "The BME/Okuma Dragster ran really well at the Winternationals, qualifying with a 4.55, so we had confidence going into Phoenix," said Miller. "Our tests have shown that the Gibson-Miller Mark II Supercharger is capable of producing high boost at high rpm. That increased boost has consequences for how we run the car, from the blower overdrive to the compression ratio. We're in the process of learning how to adjust the engine combination to take advantage of the Mk. II Supercharger's performance without overstressing the engine components." That learning process literally backfired at the Checker-Schuck's-Kragen NHRA Nationals, held at Firebird International Raceway near Phoenix. Four qualifying runs produced a series of engine backfires and a best elapsed time 4.608 seconds at 299.26 mph that left driver Alan Bradshaw 18th on the qualifying list. "The engine was running lean at the top end as a result of the boost pressure produced by our prototype superchargers," Miller reported. "Tests on our BME blower dyno after Phoenix showed what was happening, so we prepared for the next race in Houston by reducing the blower overdrive and making new pistons with a lower compression ratio. HOUSTON, WE HAVE A PROBLEM "At Houston, our plan was to use two sessions on Friday to establish a baseline with a new blower drive ratio, and then lower the compression ratio and raise the boost for two runs on Saturday," Miller recalled. "But the weather didn't cooperate, and Saturday was rained out. The good news is that the BME Okuma Dragster made the show; the bad news was that we weren't able to test the new engine combination." Bradshaw qualified the BME machine in the No. 15 spot at 4.670/313.58 mph at the O'Reilly NHRA Spring Nationals in Houston. Facing No. 2 qualifier Melanie Troxel in the opening round of eliminations, Bradshaw was first off the starting line with a .038-second reaction time. As the car went into a power wheelstand and moved toward the centerline, Bradshaw turned the steering wheel, but with the front tires in the air, the car didn't respond to his correction. He slowed to a 5.668 and Troxel took the win. "Getting adjusted to the newfound horsepower has been a challenge, but I have faith in Bill and the Team that we'll get it figured out," said Bradshaw. "Whenever you get new toys under the tree, you have to figure out how to play with them. That's the nature of the beast." VIVA LAS VEGAS The BME Team's next event will be the Summitracing.com NHRA Nationals at The Strip at Las Vegas Motor Speedway. The high-altitude track will require yet another adjustment in the BME/Okuma/Red Line Oil Dragster's setup. "Going to Vegas, we'll want a higher compression ratio to compensate for the thin air, and we'll be less aggressive with the clutch to avoid the secondary wheelstand problem that we encountered in Houston," Miller noted. "I'm going to let the car get a little further down the track before pouring the coals to it." Bradshaw is optimistic about the BME team's chances in Las Vegas: "We'll have the advantages of a really good track and the insight we've gained in the first three races," said the Texan. "I look for Las Vegas to be a turning point." BME RACE RESULTS
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