if your sessions last 25 min like mine, the factory radiator may need to be swapped to a better unit to keep engine coolant temps down. My car would creep to 240+ on a 75 degree day. With my Dewitts unit, the temp was highest in the 230 range.
'15 Z/28 #325 black a/c & stereo. 2:11 VIR Full 1:45.531 Summit Point Shenandoah Circuit
Advanced Induction cylinder heads & B-3 cam by Race Proven Motorsports.
'12 ZL1 10.52@131 1.55 60' 2:13 VIR Full (sold)