At the Track
Jim spent last winter installing a ladder bar suspension and transbrake onto his LeMans. He arrived at our Shootout to get some seat time with the new parts. “I expected it to run 10.80s in the hot Norwalk day," he says.
For his first pass, he launched at 3,400 rpm, crossed the 60-foot in 1.50 seconds, and recorded a 10.89-second e.t. at 121.69 mph. His e.t. prediction was spot-on.
“I thought my LeMans was running a little too rich, and I could improve its times by installing No. 78 jets and leaning it out," he says. Contrary to his theory, his next two passes showed no improvement. “I think I pushed the fuel delivery overly lean," he says.
To correct the issue, he installed No. 84 jets prior to his fifth pass, and proceeded to earn his best run of the day—a 10.82-second e.t. at 122.71 mph. “My LeMans is very consistent, but I’m still learning how to use jet changes to accommodate for track conditions," he explains.
Jim says he had “a very good time" at our event, and that his LeMans “hooked well and went straight."
While racing his LeMans at the 2010 Ames Performance Tri-Power Pontiac Nationals, Joe broke an axle on a hard launch and the momentum sent his car into the concrete wall. It took him two years to rebuild the car; during the process, he swapped out his 12-bolt rear for a Ford 9-inch, and upgraded his springs and shocks. His goal for our Shootout was to see if the new setup would improve his 60-foot times and keep his car steering straight.
For his first pass, he launched at 3,000 rpm, sailed past the 60-foot in 1.57 seconds, and crossed the beams in 11.10 seconds at 115.37 mph. “It was the first time since the wreck that I had my GTO back on the track," Joe recalls. “I didn’t know how it would respond, but it turned out to be a good run."
For his next three passes, Joe and his GTO performed better and better, lowering e.t.’s and picking up mph. By his fourth pass, he had clicked off a 10.95-second e.t. at 123 mph, earning him his best time of the day.
How did he do it? “I think I just needed to get used to the car again, and that’s reflected in the lower e.t.’s later in the day," he says. Tire pressure may also be a contributing factor, as the LeMans began performing more favorably after he lowered the tire pressure from 12 psi to 8.5 psi. Since he didn’t raise the tire pressure again after finding the LeMans’ sweet spot, he’ll have to test our hypothesis on another trip to the track.
So did Joe’s new rear end and suspension earn him lower e.t.’s? “No," he says. “I really thought the new combo would shave off some tenths, but my GTO is performing nearly identical to prior to the 2010 wreck."
When asked about the event, Joe says the Shootout was “very relaxed," and he was pleased that he had the opportunity to “make plenty of passes."
This month’s Shootout participants both run in the 10s, but dramatically different combos get them there. Their vehicle weights are significantly different, too. By comparing both drivers’ Strip Specs, you can see how they achieved similar e.t.’s against each other, nonetheless.
Like Jim and Joe, you may want your Pontiac to break into the 10s, and discover that a bored-out 455 block is not the only starting point to reach your goal. We’re sure the cars and combos detailed in this story will give you plenty of ideas for your project.
HPP would like to thank the management and crew at Summit Motorsports Park for their assistance in making this Shootout possible; and John Labuda, Arnie Brewer, and Billy Farrell who helped make the day go much more smoothly.
The temperature at Summit Motorsports Park ranged from 73 to 87 degrees. Barometric pressure was measured at 29.93 hg and the dew point was 57.9 degrees. The track is 853 feet above sea level and density altitude ranged from 2,177 to 3,073 feet. We'll give each racer his own correction factor based upon the density altitude at the time of his best pass. Jim's best pass occurred at 3:09 p.m.; Joe's best pass occurred at 3:07 p.m. The density altitude for both racers was 2,906 feet. The correction factors are designed to chart the theoretical best performance at sea level and will be done on the best pass only, based on e.t.