I had a conversation with KTR peroformance in MA yesterday, who has been flashing Subys with ECUtek for a couple years now.
He confirmed that most of the power they are extracting is not from simply increasing boost, then fuel accordingly. Instead, because that the car runs pig rich, particulary at WOT, they are primarily targeting leaner a/f ratios and adjusted timing tables.
where people are experiencing less severe "stuttering" after their aftermarket reflashes, I would suspect that some of the issue is related to the extra fuelling Subaru supplies in stock form. most of the graphs/data supplied here at LGT.com confirm this as well.
stock dyno run.
9.5:1 AFR from 3500rpms to redline.
final protuned dyno run
13:1 AFR falling to 11.5:1 at redline.
Stage I AFRs
about 2 points leaner again.
Dan at Mach IV
with his maps leaning out 2 pts to 11:1