20% larger "hole" or opening in the nozzle at the same fuel pressure will yield a 20% larger flow of fuel. The problem is that unless you can change the duty cycle so that the injector is running less open time when out of the boost, then you will be running 20% more fuel all of the time. The PCM or computers on most gas cars use the O2 sensor to read the AF mixture and adjust the timing on the injectors so that they don't run too rich. The diesel does not use anything like this and I believe cannot correct the on time of the injectors to compensate for the added fuel in a low demand situation like low load. If they do, then it would have to be based on boost pressure and air flow alone with no way to know that the injectors are larger. Someone in the know, let me know how the PCM would correct for a 20 % larger constant flow from the injectors and keep the engine from running too much towards the rich side all of the time.
Jess
Jess