question.....

I know that when installing a turbo you need to raise the fuel pressure. instead of using a FMU could you use larger injectors, and a pressure regulator to lower the fuel pressure?

 

It depends on how many psi you plan on running. If you go with larger injectors you will have to get a smc/afc hack to slow down the pulse at idle. An fmu will raise the fuel pressure with a ratio depending on the disc in the fmu, most are 12:1, some are 8:1. Check out the FAQ section it should answer all of your questions.