Originally Posted by E3r2E9r
That's fine, but they don't actually work the same.
As mentioned by Shiv from Vishnu, if you were to rely on the knock sensors to control ignition you would have a yard sale of parts as the subaru motors are not tolerant of knock abuse and their electronics can't reduce ignition timing like the BMW DME. The BMW DME and it's knock detection is far superior to other platforms, so one can get away with simply raising boost and adding fuel, to a certain extent. Try that on other platforms and you will be rebuilding motors on a daily basis.
I never said they work the same. I am saying that I have never seen a tuner in the business of creating custom tunes suggest that any piggyback was the way to go. All things equal and tuner wars aside being a vendor for a piggyback is not as profitable as creating maps at $200/hr.