Jan Heylen, in the #37 RS1 Porsche Cayman GT4 CS-MR (SprintX Pro-Am), lead the combined GT4 America Sprint and SprintX practice 1 field with a best time of 1:55.809. Jason Bell and his #2 GMG Racing Porsche 718 Cayman CS MR (Sprint) was second best, just .052 seconds behind Heylen. Michael Cooper, second in the Sprint championship Pro standings, would jump to third late in the session with a 1:56.045 lap time in the #10 Blackdog Speed Shop McLaren 570S GT4. Spencer Pumpelly, sitting third in the Sprint championship Pro standings, came home with the fourth fastest lap in the #66 TRG Porsche 718 Cayman CS MR with a best lap of 1:56.234.
Christian Szymczak in the #34 Murillo Racing Mercedes AMG GT4 (SprintX) would finish with the fifth fastest time with a 1:56.258, followed closely by Jarrett Andretti in the #18 Andretti Autosport McLaren 570S GT4 home with a time of 1:56.382.
The top 10 would be rounded out by Trent Hindman in the #77 Park Place Motorsports Porsche 718 Cayman CS MR, Sean Quinlan in the #19 Stephen Cameron Racing BMW M4 GT4 (SprintX), James Sofronas in the #04 GMG Racing Audi R8 LMS GT4 (SprintX) and Robby Foley in the #21 Flying Lizard Motorsports Porsche 718 CS MR (SprintX).
GT4 competitors next take to the track at 3:40pm EDT on Friday for the second practice session.