And that's the key. If you can't change the injection timing, you're really spitting in the wind, as you're wasting much of the extra fuel your putting in.You can buy all that stuff. But when I say tune an ecm I mean more give it new fuel mapping and turbo tuning for variable geometry applications. Remove it from looking at other numbers you can really tweet **** without changing hard parts if your able to gain access to that.
A bunch of the tuner boxes just increase the pulse width of the injection without correcting the timing. It's a cheap way out. It's also magnitudes easier than creating a new fuel/turbo map optimized for power or economy instead of emissions.