By day, Matt Hartford oversees the operations of Phoenix, Arizona-based Total Seal Piston Rings, producing some of hot rodding and auto racing’s highest quality and widest range of rings for internal combustion engines. As an ownership partner and CEO, Hartford possesses intricate knowledge both on the business and technical side of the coin. But eighteen weekends a year, Hartford trades his business attire for a driving suit, competing in the NHRA Pro Stock ranks — a category where technical acumen is paramount.

Hartford leases engines for his Total Seal Chevrolet Camaro from Elite Motorsports, and so horsepower is rarely a concern for he and his team. But where the magic happens from that point is often in the transmission, something which is both black art and calculated science among Pro Stock teams. Competitors in Pro Stock utilize manually-shifted transmissions with five forward speeds ands a clutch, and to sync the power to the racing surface and conditions, teams continually adjust the gear ratios in the transmission between races and rounds. Not only does the racing surface itself factor into the equation, but as the naturally-aspirated engines move from sea level (or even below sea level) to higher elevation, the power output of the engines can swing drastically. To maintain performance — or simply maximize it — teams make wholesale changes to the transmission and rear gear ratios to get the cars to launch harder, in effect making up for the loss of power (or vice versa, to slow the launch wheel-speed down in great conditions).

No greater example exists on the NHRA tour than Colorado’s Bandimere Speedway, situated at nearly 6,000-feet of elevation. At the Mile-High Nationals this summer, NHRA’s Joe Castello joined Hartford as he overhauled his transmission from front to rear, utilizing the 70-someodd gear-sets that he has at his disposal to fine-tune the Liberty five-speed for raceday.

If you’ve got some time, this walk-through of the rebuild of what is perhaps the most trick transmission in all of drag racing is well worth watching. If you ask us, just witnessing how easy and effortlessly the shafts and gears spin once assembled complete is worth your time, in itself.