Action Express Racing Cadillac’s Jack Aitken emerged as the standout performer in Friday morning’s IMSA Detroit opening practice.
With a blistering lap time of 1:07.254, the #31 Cadillac V-Series.R set the benchmark for the field, finishing 0.351 seconds clear of Renger van der Zande in the #93 Meyer Shank Racing Acura ARX-06 GTP.
The opening practice session for the 2025 IMSA Detroit Grand Prix set the tone for what promises to be a fiercely competitive weekend on the challenging downtown street circuit.
From the outset, the session was a showcase of both precision and aggression with drivers pushing the limits as they sought to adapt to the unique demands of the Detroit street circuit.
The track’s limited run-off areas and uneven surface meant that mistakes were costly, and several drivers found themselves exploring the escape roads at Turns 1 and 8.
The most notable incident occurred when Louis Deletraz in the #40 Wayne Taylor Racing Cadillac V-Series.R and Andrea Caldarelli in the #9 Pfaff Motorsport Lamborghini Huracan GT3 EVO2 tangled at Turn 1, triggering a brief red flag.
Both drivers quickly resumed, but the incident underscored the razor-thin margin for error that defines street racing in Detroit. As a consequence, both Deletraz and Caldarelli are expected to lose their fastest qualifying laps, relying instead on their second-best times for their grid positions.
As the session progressed, the battle for supremacy in the GTP class intensified and Jack Aitken driving the #31 Action Express Racing Cadillac GTP, emerged as the standout performer.
Van der Zande, a seasoned street circuit specialist, delivered a strong showing in the Meyer Shank Racing Acura securing second place with a time that kept him within striking distance of Aitken.
Meanwhile, IMSA WeatherTech SportsCar Championship GTP points leader Nick Tandy continued his impressive form by placing third in the #7 Porsche Penske 963, clocking a 1:07.651.
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Ricky Taylor piloting the #10 Wayne Taylor Racing Cadillac rounded out the top four with a 1:07.670, narrowly missing out on third by just 0.019 seconds.
The BMW RLL squad demonstrated solid pace with Sheldon van der Linde in the #25 BMW M Hybrid V8 edging out teammate Dries Vanthoor in the #24 entry for fifth and sixth positions, respectively.
Vanthoor who has dominated qualifying sessions earlier in the season was unable to replicate that form in IMSA Detroit opening practice but both BMWs remained within a second of the leader, signaling their potential threat for the remainder of the weekend.
In the GTD Pro category, the battle was equally intense. Alexander Sims set the fastest lap in the #3 Corvette Z06 GT3.R, posting a 1:10.818. Sims’ performance was emblematic of Corvette Racing’s resurgence as the American marque swept the top two positions in class.
Nicky Catsburg driving the #4 Corvette was just 0.191 seconds adrift, reinforcing the team’s dominance on home soil. Corvette’s success was built on a combination of strong mechanical grip, effective tire management, and the ability to quickly adapt to the evolving track surface.
Marco Mapelli in the #9 Pfaff Lamborghini Huracan GT3 EVO2 secured third in GTD Pro with a 1:11.138, demonstrating Lamborghini’s continued competitiveness in the category.
AO Racing’s Laurin Heinrich, the reigning Drivers’ champion and last year’s class winner, placed fourth in the ‘Roxy’ Porsche 911 GT3.R, clocking a 1:11.152. Seb Priaulx, who partnered with Heinrich for last year’s victory, completed the top five in the #64 Ford Multimatic Mustang GT3 with a 1:11.336.
The GTD Pro field, featuring a diverse array of manufacturers, delivered a thrilling display of close-quarters racing and strategic experimentation as teams explored tire pressures, suspension settings, and aerodynamic tweaks.
