From working in the industry for nearly two decades, a couple things that aren't
great about that option...
- The dyno results are simply Excel-style data plots, not raw dyno charts to show actual wheel power before/after (because no engine makes dead on what the manufacturer says, and a wheel dyno will never tell you exact crank HP/TQ).
- They make no reference to what fuel is used, recommended, or required. When you get into increasing boost and timing, the difference between 91AKI and 93AKI (or 95 and 98RON, respectively) can legitimately make a difference, let alone the drastic differences in knock protection between 87AKI and 93AKI
Piggyback's have been in use for years (it's approaching two decades specifically in the BMW turbo petrol world), and while they have come a long way, still are not a true replacement for an ECU/DME remap (because they are lying to the DME to trick it into doing what they want, instead of having specific maps for the expected values).
Just food for thought