Sebastien Bourdais finished first overall in the opening practice session of the SportsCar Weekend round at Road America in the IMSA WeatherTech championship, amid several red flag stoppages.
The #01 Cadillac V-Series.R set a time of 1:49.538s, in a practice session which saw very limited running due to the multiple red flags.
A stacked 45-car field across all five IMSA classes saw several members caught out by tricky conditions around the 15-turn Road America circuit near Elkhart Lake, Wisconsin.
Previously, 46 entries were set to run, but the #94 Andretti Autosport Aston Martin ended up not taking part.
The session was dry, but a heavy rainstorm during Thursday night meant the track surface was very green, and the grassy run-off proved treacherous in practice.
The first red flag came early in the session after Giedo van der Garde put a wheel of his #35 TDS Racing Oreca-07 Gibson LMP2 machine onto the grass at the Carousel, hitting the wall front-on.
The session returned to green with approximately one hour and 10 minutes left on the clock, only for another red flag caution to be waved less than 15 minutes later.
The second red flag came after Mathieu Jaminet went straight on at Turn 3 and into the wall in his #6 Porsche 936 and debris was left on track at Turn 13.
The issue was resolved fairly quickly, only for a third red flag to be waved following Misha Goikhberg’s heavy incident with the wall at Turn 13 in the #78 Forte Racing Lamborghini Huracan GT3 EVO2 machine.
Ten minutes later the session went to green before the fourth red flag came out after five more minutes of running, thanks to debris on track at Turn 12.
The fifth and final red flag stoppage of the session came when the #92 Porsche 911 GT3 R went into the wall at Turn 3.
In between all the stoppages some running was had across the 45-car field.
Second overall went to the #31 Whelen Engineering Cadillac, with Pipo Derani setting a time of 1:49.592s.
The 1-2 leading Cadillacs were approximately three-tenths of a second clear of the rest of the GTP field, with Augusto Farfus in the #24 BMW M Hybrid best of the rest in third.
The two Acura’s finished fourth and fifth, with the Konica Minolta #10 Acura ARX-06 of Filipe Albuquerque lapping the Road America course in a time of 1:49.930, ahead of the #60 Meyer Shank Acura of Tom Blomqvist, who set a time of 1:49.983.
In sixth place was the #25 BMW, with Nick Yelloly setting a 1:50.875 time ahead of the first of the Porsche 963s, that of JDC Miller MotorSports and Tijmen van der Helm, in the #5 car.
Eighth went to the #7 Penske-run Porsche of Matt Campbell, who set a time of 1:51.352, ahead of the #6 Penske Porsche of Jaminet, who managed to set a time of 1:51.691, despite his incident early on.
The top 10 was rounded out by Proton Competition, who were making their IMSA debut with the #59 Porsche 963.
Their time of 1:52.217 was set by Harry Tincknell.
The top three in LMP2 was led by Mikkel Jensen in the #11 TDS Racing Oreca 07 machine, with a time of 1:52.812, good enough for 11th overall, ahead of second place Ryan Dalziel in the #18 Era Motorsport entry with a time of 1:53.288, 0.4876s in arrears of the class-leading pace.
Ben Hanley in the #04 Crowdstrike Racing Oreca rounded out the LMP2 top three, with a time of 1:53.413.
In LMP3, Garret Grist led the way with a time of 1:59.030 in the #30 Ligier JS P320 machine, good enough for 18th overall.
Grist led Wayne Boyd in the #17 AWA Duqueine D08, who set a time of 1:59.133, ahead of third-in-class Matthew Bell in the second AWA LMP3 entry #13 car.
In GTD Pro, Alex Riberas set the fastest time of 2:05.206 in the #23 Heart of Racing Aston Martin GT3, but he was bettered by the GTD entry of Seb Priaulx in the #80 AO Racing Porsche 911 GT3 R, who set a time of 2:05.126, good enough for 26th overall.
Behind Priaulx and Riberas was the GTD entry of Bill Auberlen in the #97 Turner Motorsport BMW M4, who set a time of 2:05.426, ahead of Daniel Juncadella in the GTD Pro #79 WeatherTech Racing Mercedes-AMG, who set a time of 2:05.447.
And finally, Bryan Sellers rounded out the top three in GTD, with the championship-leading #1 Paul Miller Racing BMW M4 setting a time of 2:05.537, ahead of third-placed GTD Pro entry Antonio Garcia in the #3 Chevrolet Corvette C8.R, who set a time of 2:05.623.
Preparations for Sunday’s 2-hour and 40-minute race continue with second practice at 15:15 local time.
