Joao Barbosa swept to pole in the new-for-2017 #5 Mustang Sampling Cadillac DPI-V.R setting a blistering lap time of 1:36.903. The two-car team formerly known as Action Express Racing, which has won the WeatherTech Championship Prototype title all three years since the series was formed, gave the new Cadillac V-8 engine the front row in its first time out.

“We generally race better than we qualify,” Barbosa said, which could be a cautionary warning to the rest of the field. “This is going to be a tremendous race with the new Prototypes.”

Snapping at Barbosa’s heels was team-mate Dane Cameron in the #31 Whelen Engineering Cadillac, just 0.070 seconds back. A hard-fought third went to the Rebellion Racing Oreca 07 LMP2 thanks to Neel Jani’s best lap of 1:37.123. Fourth was the #10 Konica Minolta Cadillac of Ricky Taylor, who had the fastest car for most of the qualifying session before pitting before time ran out. Rounding out the top five was Jani’s WEC Porsche LMP1 team-mate Brendan Hartley who took his #22 ESM Nissan DPi to a lap time of 1:56.405.

There are 12 cars in the Prototype field – there were 11 qualifiers, as the very fast #81 DragonSpeed ORECA uncharacteristically crashed in practice earlier in the day with Loic Duval behind the wheel, and couldn’t be fixed by qualifying – the damage to the tub was too bad to repair onsite so the team gained approval to replace it with the spare from their brand new second car.