On-track action at the Chevrolet Detroit Grand Prix kicked off with the first IMSA free practice session of the day, with GM cars leading both classes in the first 90-minute session.
In GTP, Earl Bamber led the way in the red #31 Cadillac Whelen V-Series.R, posting a best lap of 1:07.182 about 30 minutes after the start of practice.
Dries Vanthoor went second-fastest in the #24 BMW M Team WRT Hybrid V8 (1:07.328), leading Nick Yelloly in the #93 Acura Meyer Shank Racing ARX-06 (1:07.384) in third.
Felipe Nasr in the #7 Porsche Penske Motorsport 963 (1:07.665) went fourth-fastest. But Nasr’s co-driver Julien Andlauer brought out a red flag halfway through the session, after contact with the wall at turn four caused debris to shed off the #7 Penske Porsche. They were the first to be penalized with the loss of their fastest lap in Qualifying later this evening.
Sandy Mitchell also brought out a red flag in the #9 Pfaff Motorsports Lamborghini Temerario GT3 after going off in the runoff at turn three, and the #9 Lamborghini will also lose its fastest lap in Qualifying. Neither incident caused major damage to either car.
Rounding out the top five in GTP was Ricky Taylor in the #10 Wayne Taylor Racing Cadillac.
In GTD Pro, the #4 Corvette Racing by Pratt Miller Motorsports Z06 GT3.R of Nicky Catsburg set the fastest time and was the only driver below the one-minute, 11-second threshold with a 1:10.921.
Ben Barnicoat in the #14 Vasser Sullivan Racing Lexus RC F GT3 set a 1:11.199 to go second-fastest, ahead of the #65 Ford Racing Mustang GT3, which set a 1:11.291 in the hands of Frédéric Vervisch.
Alexander Sims put the #3 Pratt Miller Corvette fourth on the leaderboard with a 1:11.408.
Practice 2 starts in less than two hours, at 11:30 AM ET.
Images © Jack Webster / dailysportscar.com
