Lapping the legendary 17-turn 3.74-mile airport course in 1min49.360sec, the #7 Acura ARX-05 edged Sebastien Bourdais’ JDC Miller Motorsports Cadillac DPi-V.R by just 0.035sec to earn top spot.
This pair were over 0.4sec clear of the field, but the competitive picture was blurred by a nine-minute-long red flag period caused by the need to recover the spun Performance Tech Motorsports LMP2 car of Patrick Byrne, leaving just five minutes on a crowded track for 31 cars to set a time.
Ex-IndyCar driver Matheus Leist made it two JDC-Miller Cadillacs in the top three, as he eclipsed the best time set by Ryan Briscoe in Wayne Taylor Racing’s similar Caddy. Briscoe and Renger van der Zande, who are again partnered this weekend by six-time and reigning IndyCar champion Scott Dixon, lie just two points behind Castroneves/Ricky Taylor in the IMSA DPi championship fight.
Felipe Nasr’s Action Express Racing Cadillac was fifth ahead of the two Mazda RT24-Ps of Harry Tincknell and Oliver Jarvis, while outgoing DPi champ Dane Cameron was eighth in the second Acura.
In LMP2, Simon Trummer’s PR1 Mathiasen Motorsports entry led Matt Bell’s Inter Europol car by one second.
The two Porsche 911 RSRs, in their final IMSA outing for the forseeable future, headed up GT Le Mans class, Fred Makowiecki 0.374sec faster than Laurens Vanthoor, who was a mere 0.021sec ahead of Connor De Phillippi’s BMW M8. The two Corvettes of Tommy Milner and Jordan Taylor were 0.9 and 1.2sec off the ultimate pace, but this is likely unrepresentative.
The AIM Vasser-Sullivan Lexus RC Fs were first and third in the hands of Jack Hawksworth and Townsend Bell, split by the Wright Motorsports Porsche 911 GT3R of Pat Long.
Andrew Davis produced his customary fine job to slot the Audi R8 of Hardpoint Racing into fourth, a mere 0.02sec faster than Lawson Aschenbach’s Riley Motorsports Mercedes-Benz and 0.035sec ahead of Roman De Angelis in the Heart of Racing Aston Martin Vantage.
The second session begins at 2.35pm local (Eastern) time.