ThunderMax for 2018 - 2020 Softail® Models
Part Number: 309-589
ThunderMax is an award-winning, performance ECM designed specifically for EFI-equipped Harley-Davidson® motorcycles. This advanced, stand-alone tuning system uses proprietary AutoTune technology with wide-band oxygen sensors to deliver unmatched performance, rideability, and adaptability.
The ThunderMax ECM comes fully assembled, ready to install, with no wire-cutting or splicing required. Simply replace the factory ECM and oxygen sensors, load a base map, and ride. Installation is quick, and the system immediately begins tuning itself to your bike.
With built-in knock control for timing adjustment, ThunderMax offers precise spark management in real time. It retains full factory functionality and works seamlessly with factory systems. Wide-band O₂ sensors continuously read the air/fuel ratio, automatically making live adjustments across every throttle position and RPM range. No dyno is required, and once you key off, all changes are instantly written to the ECM.
The ThunderMax software is free to download from our website and provides full access to tuning tools, diagnostics, and data collection. Riders can monitor, record, and examine critical information such as engine temperature, RPM history, diagnostic codes, and more.
The result? Sharper throttle response, stronger rideability, and that deep, tuned exhaust note that makes the bike yours. Compatible with high-performance cams, turbo, nitrous, and supercharger applications, ThunderMax 309-589 is engineered, built, and supported in the USA.
This product is intended for "RACE READY" vehicles only and is not for sale or use on vehicles otherwise subject to emission control requirements. In the state of California, this product should not be used on any vehicle that is registered for use on public roads. Please view the ThunderMax 50 application guide for "STREET APPROVED" & ARB compliant produ