Whelen Engineering Cadillac DPi driver Felipe Nasr set the fastest lap in a red flag-affected opening practice session for Saturday’s Motul Petit Le Mans at Michelin Raceway Road Atlanta.
Nasr, driving the No. 31 Cadillac DPi-V.R, went to the top of the leaderboard with a time of 1:09.093 set in the second half of the hourlong Thursday morning session.
The Brazilian’s fastest lap came just before the session was red-flagged for a second time after the second of two incidents involving GT Daytona cars.
AIM Vasser Sullivan’s No. 14 Lexus RC F GT3 caused the first stoppage less than 10 minutes into the session when Jack Hawksworth stopped the car at Turn 2 with a puncture.
The second red flag occurred with just over 17 minutes to go, when Marco Seefried went off-track in the No. 48 Paul Miller Racing Lamborghini Huracan GT3 Evo.
This latter event forced the session to be extended by five minutes, but with no improvements on the board, Nasr came away with the fastest lap.
Ricky Taylor went second-quickest in the No. 7 Team Penske Acura ARX-05 DPi, with the Brazilian lapping six-tenths of a second shy of Nasr and two-tenths quicker than his Penske teammate Dane Cameron.
Fourth-fastest was Colin Braun in the No. 54 CORE autosport Nissan DPi, ahead of Matthieu Vaxiviere in the No. 10 Wayne Taylor Racing Cadillac.
The best of the two Mazda RT24-P DPi machines lapped sixth-fastest in the hands of Timo Bernhard, who produced a best time of 1:10.169 in the team’s No. 77 car.
In the GT Le Mans class, Richard Westbrook led the way for Ford Chip Ganassi Racing with a time of 1:16.810 behind the wheel of the No. 67 Ford GT.
This edged Westbrook 0.092 seconds clear of James Calado in the No. 62 Risi Competizione Ferrari 488 GTE Evo, while Dirk Mueller scored third in the No. 66 Ford on a 1:16.982.
The top four cars were separated by less than four-tenths of a second, with Nick Tandy going fourth in the No. 911 Porsche 911 RSR, beating John Edwards and Tom Blomqvist in the two Team RLL BMW M8 GTEs.
Quickest in GT Daytona was the No. 96 Turner Motorsport BMW M6 GT3 in which Bill Auberlen registered a time of 1:19.306.
This put the Turner car just under three-tenths clear of Hawksworth, who managed to recover the No. 14 AIM Vasser Sullivan Lexus after its early stoppage.
In LMP2, Kyle Masson paced the class in the No. 38 Performance Tech Motorsports Oreca 07 Gibson.
Next up for the IMSA WeatherTech SportsCar Championship field is Practice 2, taking place at 2:50 p.m. ET.
RESULTS: Practice 1