After Hall had been away from the sport for several years, Lola importer Carl Haas approached him with a proposition: Let's go Indy car racing. Haas would provide the sponsors and cars (Lolas), Hall could concentrate on running the team. That appealed to Hall and the pair formed Haas-Hall Racing. When the money to go to Indy didn't materialize, they switched to the SCCA Formula 5000 open-wheel series.
Near the end of the run, the sponsorship to go to Indy did materialize, and Hall began to focus on that arena. The results again were immediate. In 1978, the team's initial season of Indy car competition, it became the first and still only team to capture Indy car racing's Triple Crown, with victories at the Indianapolis 500, Pocono 500 and California 500.
But the success in the long-distance races hid the shortcomings of the Lola chassis and Hall decided to take one last stab at car-building. He commissioned up-and-coming designer John Barnard to realize his vision of a new kind of Indy car based on the ground effect principle introduced on Colin Chapman's Lotus 78. The resulting Chaparral 2K, nicknamed the “Yellow Submarine” thanks to sponsor Pennzoil's brand colors, changed the face of Indy car racing. The first Indy “tunnel car” dominated the 1979 Indianapolis 500 in Al Unser's hands until sidelined by a transmission issue. It came back the following year and not only won the 500, but captured the 1980 CART PPG Indy Car World Series championship as well with Johnny Rutherford at the helm.
After the 1981 season, Hall remained in Indy car racing off and on with store-bought Lola and Reynard chassis and collected more wins and high finishes with a variety of drivers, including John Andretti and Gil de Ferran. Hall retired from the sport after the 1996 campaign.