We then hit the track and let this baby rip. Unfortunately, weather conditions were not similar to our bone-stock baseline (baseline 61-degrees, 35 percent humidity, 30.08 barometer, vs. 475 HP Pac w/68-degrees, 81 percent humidity, 29.91 barometer). Low e.t. was a respectable 12.59 at 112.29 mph and we ran a string of 12.60s. The humid, bad air served us notice that with good air 12.40s were waiting to be unleashed by this new Hemi Challenger.