ThunderMax Auto Tune 309-382 for 2012-Newer Harley Davidson Dyna Motorcycles ThunderMax with AutoTune is the industrys first and only stand-alone Performance EFI Engine Management System developed specifically to meet the tuning needs of H-D motorcycle owners. This highly advanced tuning system allows the user to support a wide range of performance upgrades with ease. The all new ThunderMax AutoTune module includes all of the great performance enhancements that made the brand famous  with benefits youll notice immediately, including quicker throttle response, increased power and cooler operating temperatures. The ThunderMax with AutoTune is a Wide-Band, Closed-Loop system which means it continually and automatically adjusts your air-fuel ratios every time you ride, regardless of changes in ambient conditions. All you have to do is ride and enjoy! The ThunderMax System can never be out grown... Change pipes, add cams, whatever! Just download a new map. ThunderMax software, firmware and map updates are accessible 24/7 with an internet connection.