ThunderMax ECM with Integral Auto Tune System for Harley-Davidson
*** ONLY FOR FUEL-INJECTED MOTORCYCLES ***
The ThunderMax ECM with Integral Auto Tune System is the ultimate solution for riders seeking to unlock the full potential of their Harley-Davidson®. Designed to replace the factory Electronic Control Module (ECM), this stand-alone system eliminates the limitations of stock lean fuel maps and the need for expensive dyno tuning. By utilizing proprietary Auto Tune technology and wide-band oxygen sensors, the ThunderMax continuously adjusts the air/fuel ratio in real-time for every riding condition. Whether you are running a stock engine or a high-performance build with cams and exhaust upgrades, this system ensures immediate throttle response, cooler operating temperatures, and smoother rideability.
Features
- Integral Auto Tune: Continuously monitors and adjusts AFR targets while you ride—no manual mapping required.
- Wide-Band Accuracy: Includes two 18mm Bosch wide-band oxygen sensors for precise data feedback.
- Knock Correction: Actively monitors for detonation and adjusts ignition timing on the fly for added protection and optimized performance. (M8 and newer models.)
- User Adjustable: Allows modification of idle speed, rev limit, and speedometer calibration via TMax software.
- Adaptive Learning: Automatically compensates for ambient weather changes, altitude, and exhaust modifications.
- Diagnostic Capable: Reads and clears diagnostic trouble codes (DTCs) and logs performance data.
- Made in the USA: Engineered and manufactured with high-quality components.
Technical Specifications
- System Type: Wide-Band Closed-Loop EFI System.
- O2 Sensor Thread: 18mm x 1.5 (Requires 18mm bungs in exhaust).
- Tuning Resolution: Adjusts every 256 RPM and 1.5 degrees of throttle position.
- Mounting: Direct OEM Replacement Footprint (Fits stock ECM caddy).
- Connection: Plug-and-Play Factory Harness Connectors (No splicing required).
- Compatibility: Supports Turbo, Nitrous, and Supercharger applications.
- Includes: ECM, wideband oxygen sensors, USB cable and instructions.
Critical Fitment Notes
- Center Cooled / VVT Models (309-605): The 2023.5+ CVO and 2024+ Touring models with the new fairing design (Center Cooled) require part number 309-605, which fits both VVT and Non-VVT variants of the new body style. This unit fully preserves all factory features, including ride modes, cruise control, navigation, and Wi-Fi connectivity.
- Exhaust Requirement: This system uses 18mm wide-band O2 sensors. If your exhaust pipe is equipped with smaller 12mm ports (common on 2010+ Touring, 2012+ Softail/Dyna, and 2014+ Sportster), you MUST install 18mm bungs or use an exhaust system designed with 18mm ports.
- Map Loading: System requires loading a base map via a Windows PC prior to first start (Software and USB cable included).
Regulatory & Emissions Notice
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” and CARB-compliant products.
***THUNDERMAX EMISSIONS NOTICE***
Harry Speckman –
no mess, “easy” to install, works great
Joe Pinedo Jr –
Email for technical support and they helped me thru every step.
Job –
First off let me say I’m a mechanic. My Bike has never ran this good. The auto tune is amazing. Runs so clean and smooth. Very easy to set up and load tune. Don’t waste your money on the other junk (power commander) unless your trying to blow up your bike. will definitely purchase one for my next bike(s)
Chris M. –
Correct part and and great service
Gregory O. –
Closed loop auto tune is best. No going to dyno after mods.
Jon K. –
Product is awesome and has made my bike preform even better then before.
Rene Ramos –
Awesome tuner. Do it yourself.
Greg C. –
Very simple installation
Chad Lewis –
Can’t wait. Exactly what I ordered.
Marques –
Awesome product!
Dale Pash –
Easy to install just follow the instruction. Plenty on youtube for visual affect. Customer support is outstanding!
Larry Crow –
Best price i could find had to add 18mm bungs no big deal with a little luck ill be riding in a few days then I’ll send video and smile on face
Anonymous –
Good product would recommend.plus great price to
Alan P. –
Good price, easy order, fast delivery
james crews –
Great Product Best Pricing
Edward U. –
The Thundermax ECU was relatively easy to install and load the base map. I had to have 2 new O2 sensor bungs welded onto my exhaust because the locations for the previous bungs wouldn’t work (Sawicki RT Shorty) on my 2022 Lowrider ST.
Anonymous –
Quality
Parley Mortensen –
So far I am very happy with my purchase.
Bruce S. –
Great efficient service, no hassles to send to New Zealand either. Great results.