ESPN

Tracking In Dirt

Written by Ryan McGee

Visuals by Andrew Kornylak

The NASCAR Cup Series returns to Tennessee’s Bristol Motor Speedway this weekend, competing on the same red dirt the sport’s roots were planted on nearly 75 years ago.
ESPN followed the entire three-month process of converting the legendary half-mile, high-banked concrete oval into an old-school dirt track.
In 2000 and ’01, Bristol hosted the big leagues of dirt racing, the World of Outlaws. Today’s installation process is similar, but with much more science involved.
The track clay is all local. The base layer is made of ’00-01 dirt that was recycled into a racetrack parking lot. The top “Race Layer” was excavated from nearby Bluff City, Tennessee.
The first trucks couldn’t roll in until Jan. 7, because the racetrack had to remove more than 1 million lights from its annual Christmas show.
It took two weeks for more than 2,000 trucks to deliver over 23,000 cubic yards of red clay weighing roughly 30,000 tons, the equivalent of a pair of Brooklyn Bridges.
Four layers of clay were laid down atop a sawdust base by bulldozers and graders guided by a GPS system accurate to within five-hundredths of an inch.
Bristol’s signature 24- to 30-degree high banks have been cut to 19 degrees via 8 to 10 feet of fill dirt. Flatter turns hopefully will help 3,400-pound Cup cars make slide job maneuvers.
Before the surface is packed in, it’s tilled. Aerating the dirt allows moisture to work its way deep into the layers below.
Water keeps the surface slick and dampens dust. With a midday sunshine-soaked start planned for Sunday, expect to see the 2,500-gallon water truck crawling through laps during every break in the action.
Before Thunder Valley, USA, hosts race cars, four-door Bluesmobiles that simulate stock car weight, called “packer cars,” run endless hot laps to prime the surface.
Timing and scoring loops are installed beneath the dirt, communicating with transponders inside the race cars to track speed and race running orders.
The thicker track surface caused the massive Turn 3 gate to be removed and replaced so NASCAR teams could still drive their 18-wheeler transporters through and enter the infield garage.
Unlike asphalt racing, where race cars are led largely by the nose, dirt racing is about staying loose and letting the right rear guide the car through turns.
Steering becomes counterintuitive. Drivers must know when to point the front tires away from the turn, instead of into it, waiting for the rear end to come around, ready to follow.
Bristol dirt laps should run around 7 seconds and 37 mph slower than the 14.8-second, 129 mph concrete pace. Reduced speeds meant the “soft wall” barrier could be removed to make room for the bulkier surface.
Will Sunday’s dirt race be one of a kind or the first of many? Two-time Bristol winner Joey Logano isn’t sure. “I just want my car to survive the event,” he said, laughing.
  • Additional reporting by Andrew Kornylak.
  • Additional visuals courtesy of Getty Images,
  • Bristol Motor Speedway, Brendon Bauman Photos,
  • State Archives of North Carolina