ThunderMax AutoTune EFI System for Harley-Davidson
Unlock the full potential of your Harley-Davidson with the ThunderMax AutoTune EFI System—an industry-leading self-tuning fuel management solution designed for real-world performance. Whether you're running a stock setup or a fully built big-inch motor, ThunderMax continuously adjusts your air/fuel ratio in real time for maximum power, throttle response, and engine efficiency.
Unlike traditional flash tuners, ThunderMax uses wideband oxygen sensors and AutoTune technology to actively monitor and correct fueling as you ride. No guesswork, no repeated dyno sessions—just consistent, optimized performance every time you twist the throttle.
Why Choose ThunderMax?
True AutoTune Technology
ThunderMax continuously learns and adjusts fuel delivery based on real-time riding conditions, including altitude, temperature, and engine load.
Wideband O₂ Sensors Included
Equipped with Bosch wideband sensors for precise AFR targeting—far superior to narrowband systems used in factory ECUs.
Maximizes Horsepower and Torque
Optimized fueling and ignition timing deliver measurable gains in power, smoother acceleration, and stronger pull throughout the RPM range.
Plug-and-Play Installation
Direct replacement for your factory ECM using OEM-style connectors. No cutting, splicing, or complicated wiring required.
Built for Performance Builds
Ideal for:
- Big bore kits (114", 117", 124", 128"+)
- High compression engines
- Performance camshafts (Woods, Feuling, S&S, etc.)
- Aftermarket exhaust and intake systems
Performance You Can Feel
With ThunderMax, your bike adapts as you ride:
- Crisp throttle response with minimal hesitation
- Stable idle and smoother cruising
- Improved fuel efficiency under normal riding conditions
- Consistent AFR under aggressive riding
Whether you're riding hard or cruising long distances, ThunderMax keeps your engine properly tuned at all times.
Key Features
- AutoTune closed-loop fuel control
- Wideband oxygen sensor system
- Pre-loaded base maps for common Harley setups
- Adjustable AFR targets
- Integrated ignition timing control
- USB interface for advanced tuning and data logging
- Compatible with most aftermarket performance upgrades
Fitment
Available for a wide range of Harley-Davidson models, including:
- Touring (Road Glide, Street Glide, Road King)
- Softail (Milwaukee-Eight and Twin Cam)
- Dyna models
- Select Sportster applications
Be sure to select the correct model and year variant for your motorcycle.
Why Buy from TMF Cycles?
At TMF Cycles, we build and tune high-performance Harley engines daily. We understand what works and how to get the most out of your setup.
- Expert support for performance builds
- Real-world tuning experience
- Fast shipping and trusted brands
- Built for riders who demand more
