The Burger Motorsports Power Box was a popular ECU "piggyback" tune for the BMW E90 325i, 328i, and E60 528i, offering improved throttle response and increased horsepower. The Power Box allows for throttle remapping that can be adjusted for 0%, 30%, 60%, or 100%. This operates independent of engine tuning, which can be turned on or off, and adds a claimed 10 horsepower at the crank, and a better power curve. The Power Box will come with PDF instructions for installation from Burger Motorsports.
This Power Box was removed from my old 330i and has been in storage.
Happy to answer any questions!