Stock rev limit is 7500 that loud "pop" is most likely the car running out of fuel at that level due to the 16g. I wouldn't recommend taking it to that rpm until you have more fuel and a way to log what is going on with the car.

I have a walbro 255 but I think previous owner has in stock injectors I have 1450 on the way

Sounds like fuel cut which is based off airflow. Basically your overrunning the stock mass airflow sensor so it cuts fuel. You can remove the honey comb from the unmetered section(of the MAF sensor) and remove the screw to help reduce fuel cut. Thing is you need larger injectors and a way to tune(ecmlink or comparable) to boost past 15psi with a 16g. More boost on a bigger turbo(16g) means a better intercooler will be needed. My suggestion would be to turn the boost down until you can get what you need in order. Having the car mechanically in tip top shape would be my #1 suggestion if that hasn't already been done.

Def fuel cut my 2g would hit a brick wall, my buddies 1g would pop and keep pulling, sounded far more violent