I don't have "real data", but I looked back thru my videos from last year and top speed from the tach was at 8100rpm in 5th --> 138mph. slowest corner was 6000rpm in 3rd --> 58mph.
That was good enough for 3rd in EP behind Matt Reynolds and Andrew Robertson. Reynolds was ~3.5sec faster than I was, and it was his first time at the track as far as I know.
I was also fighting handling issues--- just switched to radials and I was still running a bias-ply alignment. It was pushing really bad on corner entry, so my apex speeds are slow since I couldn't make it turn.
Soooo, add in the excuses and what-ifs and YMMV. it's at least a ballpark to shoot for though.