Callaway’s new racecars and team ready for ADAC GT Masters’ Opener. No. 31, Whelen Motorsports C7 GT3-R - Americans Boris Said and Eric Curran, with Loris Hezemans substituting for Curran in selected races, including Oschersleben. The ADAC GT Masters series begins its 10th anniversary season this weekend at Motorsport Arena Oschersleben. The tough, 3.7-km (2.3-mile) German road course will host the first of seven events on the 2016 ADAC GT Masters calendar, with race weekends scheduled this ...