This ignition kit is specially developed for all Twin Cam and Sportster 2003-2006. These motorcycles are using the SAE J1850 data bus for communication between the ignition module, instrument cluster, turn signal/security module and diagnostic scan tools. This ignition module fully supports this new data bus including the use of a HD scan tool to read sensor data and clear diagnostic codes. The ignition module TC88A features built in data logging that stores data for the last 30 minutes of engine operation including RPM, vehicle speed, manifold pressure, ignition advance and battery voltage This feature is very handy for tuning and diagnosing problems. The included PC link cable and Windows compatible software allows the use of a laptop PC to program a custom curve, download data from the unit and access features such as speedometer recalibration to accommodate tire and gear changes. Kit includes a high output Twin Cam coil, universal spark plug wire set, an external plug-in ignition module, Twin Tec software and a PC link cable.