looking for a balanced +max turns settings

I have added about 300 turns to the marathon game speed. i thought i had a good balanced progression and had changed the intervals ect to theoretically end each era in its historical end year ect. My first attempt was too fast, i was researching refrigeration in the year 2005 for example. and now my second attempt is too slow with laser research being done in the year 1900 lol.
i was wondering if anyone has a good balanced +max turn edited xml for me to copy. i want to end each era around the time of the realistic timelines.
classical era ending around 700-800 AD
medieval ending around 1400
renaissance ending around 1700
ect ect

That's hard as hell to archieve. Keep in mind you can beeline to certain techs, entering sooner to each era. You can focus on science and therefore enter into later eras sooner, also AI could do similar things.

To keep some historically accurate dates the entire tech system must be reworked somehow, not just research speed.