John McLeod’s 2009 Dodge Drag Pak Challenger was already a rare and serious race car, but a comprehensive electronics and data-acquisition upgrade has taken its performance to another level. With Holley Dominator EFI at the center of the system, Racepak data logging and display technology, and Classic Instruments gauges connected through a single CAN network, McLeod and crew chief Donnie Cummins can monitor everything from individual-cylinder air/fuel ratios to shock movement, ride height, and track temperature. The results came quickly—the Challenger recorded its quickest pass ever during its first full run with the new setup. Watch the video to see how this integrated system gives the team the data and control needed to fine-tune the Drag Pak for quicker, more consistent passes.