Trying the 3rd time to break into 1:50 at Sonoma but I still failed. The first session has great grip and car is more willing to rotate, but the sun was at T8 and T10, made it difficult to drive it to the limit there. The 2nd and 3rd session was a bit hotter and the car started to understeer at entry. I lost a lot of time at T6 and overall a bit slower in despite I was a bit faster after T7. My car also throwing CEL in session 3 and it turned out to be misfires in cylinder 3 and 4. So I gave up for the day. I still don't know what caused the misfire. 
Any way, I did 3 laps with 1:50.7-1:50.8 in the first 3 sessions. The setup definitely has 1:50 in it. Maybe next time after I fixed the engine.

Mods:

225/45/17 Nankang CRS v2. 15 heat cycles
Enkei TS5 17x8 ET45
Bilstein B6 with Tein H Tech springs, front pedders tophat and double camber bolts, front bumpstop replaced with Bilstein E4-AP2-Z118A00. Rear OEM bumpstop was trimmed by 1/3
Perrin 19mm front sway bar, stiff slot.
Blox 17mm rear bar, medium slot
SPL RLCA (pre-weight saving version), mounted at higher holes.
Camber: -3.5/-2.5 F/R; Toe: -1/16 / 1/32inch F/R
AP Racing Endurance front BBK with Powerstop Re-manufactured PP rear brake. Endless CC43 brake pads.
Verus Rear diffuser
Nameless Axle back exhaust
Mobil1 0w40 FS, SYMS oil pan, 0.7qt overfill over max line. 
CANMIM oil pressure data injector kit designed by me.