Overnight conditions at Suzuka Circuit shifted dramatically for Sunday, April 21, trading the bright sunshine of previous days for a hazy, overcast morning. Despite the grey skies and lack of rain, the track remained completely dry as the thirty-minute free practice session for the All Japan Super Formula Championship kicked off at 8:35 AM.
With the race looming, drivers queued up in the pit lane before the session even began, eager to make the most of the crucial warm-up. Teams split their strategies immediately, sending cars out on a mix of soft and medium tyres to dial in machine balance before moving on to pit stop and start practice exercises.
Sho Tsuboi (P.MU/CERUMO･INGING) wasted zero time making an impression, putting his No.39 machine straight to the top of the timing sheets with a 1 minute 38.700 lap. Having spent the night repairing his car following a crash during qualifying, Tsuboi pushed hard right from the get-go to confirm the vehicle's condition.
While most of the field focused on race simulations with heavy fuel loads, trouble struck midway through the session for Ryo Hirakawa (ITOCHU ENEX TEAM IMPUL). The No.20 car suffered a suspension problem that forced Hirakawa to park in the escape zone on the outside of the Spoon curve and step out of the machine. Even so, he had already laid down a 1 minute 39.434 lap on soft tyres, good enough for second fastest in the session.
Behind the leaders, Yuhi Sekino (ITOCHU ENEX TEAM IMPUL) in the No.19, Tomoki Nojiri (TEAM MUGEN) in the No.16, and Alex Palou (TCS NAKAJIMA RACING) in the No.64 all displayed strong long-run pace with minimal tyre degradation. Palou, piloting the No.64, carried plenty of confidence into the day following extensive long-run testing during the off-season.
Further down the order, polesitter Tadasuke Makino (TCS NAKAJIMA RACING) used the session to evaluate both tyre compounds by starting on softs before switching to mediums, ultimately posting a 1 minute 40.582 best to finish tenth in the No.65 car. Meanwhile, Naoki Yamamoto (DOCOMO TEAM DANDELION RACING) spent the entirety of the running on soft tyres, clocking a 1 minute 40.231 best to wrap up the session in eighth position.
