So you think maybe the wrong disc in the FMU? Or would it be something with having no voltage clamp or missing link? Like I said, the first month everything was installed the car was running great... from fifth gear I could give it throttle and it would go. Now if i give it throttle in fifth gear it uses whatever it has in raw horsepower to increase speed but as it goes into boosting it starts all that leaning out (according to a/f gauge) and stuttering crap. It's like this happens when there's not much hp already built up and it has to build hp from boost. By the way, the car has a rebuilt bottom end with forged parts - rods, pistons, headwork, etc. So it should be ready for all this but this fuel issue has been haunting me since a month after turbocharging.

And I guess ur right about the 4:1 fmu. For some reason I had in my mind 12:1. But this is my fmu, looks exactly like it anyway, haha.