GT3s are not untouchable and it certainly depends on the year and driver, but for sure are very very fast. Here are 3 GPS speed graphs, same track all with the same driver (me) and all within 1.2 seconds with the ZLE the fastest:
1) My ZLE against a lightly modded 991.2 GT3RS (ZLE is black)
2) My ZLE against a new 992 GT3 (manual) This was my ZLE at it's worst against a brand new 2023 GT3 on Cup 2s, all stock. (ZLE is blue)
3) All 3 together - (ZLE blue, SLE red, 992 GT3 black)