Whelen Engineering Racing Cadillac driver Felipe Nasr set the pace in a red flag-affected first Motul Petit Le Mans practice session at Michelin Raceway Road Atlanta.
In chilly fall conditions, Nasr topped the timesheets in the No. 31 Cadillac DPi-V.R that he shares with Mike Conway and Pipo Derani courtesy of a 1:09.508 lap that the Brazilian registered approximately 25 minutes into the one-hour session.
The Action Express-run Whelen Cadillac and the No. 01 Chip Ganassi Racing Cadillac were the only cars to break the 70-second barrier, as Renger van der Zande posted the second-fastest time aboard the latter DPi machine.
Van der Zande initially went quickest overall with his 1:09.758 effort, only to be beaten by Nasr just a few moments later.
Early pace-setter Dane Cameron ended up third-fastest on a time of 1:10.094 set behind the wheel of the Meyer Shank Racing Acura ARX-05.
After waiting around 20 minutes before hitting the track, FIA World Endurance champion Kamui Kobayashi posted the fourth-best number in Action Express Racing’s Ally Cadillac, which is taking part in the Michelin Endurance Cup races only this year.
The opening half of Practice 1 ran smoothly but the second half was interrupted by a pair of red flags.
Mazda driver Jonathan Bomarito caused the first stoppage on 33 minutes when he pulled the No. 55 Mazda RT24-P DPi to the side of the track with an apparent mechanical issue. The Mazda did not return to the track after being towed back to the pits.
The second red occurred after 48 minutes when Steven Thomas’ WIN Autosport Oreca 07 Gibson came to a halt just before the chicane. There was also a number plate from the Performance Tech Ligier LMP3 that needed to be cleared from the track at Turn 9.
As Cadillac entries led the way in DPi, Porsche 911 RSR-19s ran first and second in the GT Le Mans division with Frederic Makowiecki beating his WeatherTech Racing teammate Mathieu Jaminet by 0.158 seconds.
The Proton-run Porsches lapped more than half a second quicker than the rest of the GTLM field, which was headed up by Corvette Racing’s Antonio Garcia on a 1:17.515. The best BMW M8 GTE run was a 1:17.562 laid down by Jesse Krohn.
Gabriel Aubry set the tone in the all-ORECA LMP2 category with a 1:11.718 run aboard Tower Motorsport’s No. 8 Gibson-powered prototype.
The Frenchman ended up two-tenths ahead of Wayne Boyd who ranked second for United Autosports, while the problematic No. 11 Win Autosport car came through in third.
The LMP3 category was led by Colin Braun in the No. 54 CORE autosport Ligier JS P320 Nissan on a 1:15.916 lap time.
Braun narrowly beat Jr III Racing’s Spencer Pigot by just under six hundredths of a second.
Bill Auberlen beat IMSA rookie Frederik Schandorff to the top spot in GT Daytona, as the Turner Motorsport BMW M6 GT3 led from the Inception Racing McLaren 720S GT3.
The second practice session for the IMSA WeatherTech SportsCar Championship field takes place at 2:20 p.m. ET.
RESULTS: Practice 1