Hello, I am trying to figure out what CC injectors i would need for my engine. Shooting for a 400hp build with a T3/T4 .63 ar turbo. I was trying to use the formula but I got to confused and thought I would ask here as well. Any help is greatly appreciated.

T3 is just a flange size that tells Nothing of the Turbo specs itself. Do you even have a forged bottom end? What is your compression? And what are you using to tune everything? That will help determine what size injectors would be suitable. Are you going to run e85 or what? More info needed.

Forged bottom end, 8.8:1 compression. Everything else is stock. Walboro 255 fuel pump. Using MS2 for tuning. Any other details needed?

If you're looking for a general answer, some 72lb/hr injectors will most likely offer enough fuel and enough overhead for 400HP, depending on the fuel pressures you're running.

If you have Megasquirt then ID1000's FTW I got them so I can run e85 but im still on pump. they can make all the power you need on pump gas with these motors.