hey i have an 02 wrx and im looking to hit close to 400hp at crank. it already has spt intake with spectrum filter, 3in catless dp and TBE. Sti IHI turbo with jdm injectors. has sti TMIC, im looking at getting a walbro 255LPH pump and getting the 850cc injectors, with wide band air sensor to monitor. it has an open source tune on it, it curently boosts 13-14 psi. what else should i do?