Here you go buddy I am sorry it took me so long to get this done this is good for the T9+ 18 chip version that you have.

Please give this a stest and let me know how it works for you. I locked it to 8.8v so expect an increased power draw over stock but your overclock limit should increase quiet a bit because of this but you need to do trial an error and work it up slowly since I couldn't find public data for the T9+

Please report your results

https://github.com/taserz/S9-Volt-Rocket-Ship/raw/master/bmminer880_T9%2B