Matt Plumb and C360R posted the fastest time of the opening two practice sessions of the weekend for the Continental Tire Sports Car Challenge at Circuit of The Americas, laying down a time of 2:19.832 in the second practice of the day.
Plumb’s time in the No. 76 McLaren 570S GT4 was just 0.085 seconds faster than Dillon Machavern in the No. 28 RS1 Porsche Cayman GT4 Clubsport MR, who also set his fastest lap in the second practice of the day.
Guy Cosmo was the third and final driver to dip into the 2:19’s, pacing the opening practice of the weekend with a best lap of 2:19.966 for Team TGM in the No. 4 Porsche Cayman entry.
Nico Rondet for C360R and Marc Miller for CJ Wilson Racing completed the top five across the two sessions in the GS class on Thursday.
In ST, Spencer Pumpelly was the man to beat for RS1 in the No. 17 Porsche Cayman, with the Murillo Racing pair of Christian Szymczak in the No. 34 Mazda MX-5 and Eric Foss in the team’s No. 56 Cayman completed the top three.
Mat Pombo’s MINI and Owen Trinkler in the CRG-I Do Borrow Nissan Altima rounded out the top five. The top four times in ST on Thursday were set in Practice 1.
Both sessions ran without incident and the only red flag was displayed for a track inspection in the first practice.
Of note, the Stevenson Motorsports Chevrolet Camaro GT4.R managed only eight laps in Practice 1 and just five laps in Practice 2 while dealing with gearbox issues, but the team indicated the car will be ready to go for Friday.
The Camaro is making its IMSA debut this weekend after debuting in Pirelli World Challenge earlier this year.
The Continental Tire Challenge series returns to action Friday with a 20-minute practice from 10:45 a.m. CT to 11:05 a.m., followed by qualifying for the race at 11:15 a.m.
The two-hour Circuit of The Americas 120 is scheduled to start at 2:45 p.m. with live coverage available at www.IMSA.tv.