hy well at first her is my configuration after a engine rebuild:

piper cam 285
mongoose exhaust
bailey dump valve
bailey oil breather
new stage 2 t3 turbo

7200 rpm rev limit (black box)
turbosystem ecu chip (appartly a no limit)

i set my boost on 1.4-1.5 BAR 20-21 PSI

i put my AFR on idle 14.7 and when i drive the car my afr is at 11.11 also on boost (after setting the black fuel pressure box on the meetering unit )
the car runs fine

but i have a BUG or like little missfire when i am in the 3 gear puch full throttle and at 4000 rpm it sound likee BRRRRRRRRRRR i hear the sound in the end exhaust pipe and the boost drop
only when i throttle very slowly it looks fine
...

can it be that my ignition timming is not good need to put it 12 degree before pmh no?

i also saw that my 2 green O-rings seal on the pressure black box on the meeering unit are done because i have a little fuel leak on it need to replace this 2 o rings

thank you