The following is a list of Frequently Asked Questions and basic information regarding ThunderMax Performance EFI Systems:

1. What is ThunderMax?

ThunderMax is an industry award winning, performance engine management system for EFI equipped Harley Davidson models. The ThunderMax ECM replaces the stock module and helps “unlock” various performance advantages not possible by “Flash” systems and other post-fuel “piggy-back” tuning devices. ThunderMax’s key performance advantage relies upon its proprietary AutoTune technology which utilizes 18mm Bosch wide-band oxygen sensor feedback to provide continuous AFR tuning corrections based upon riding conditions like temperature and altitude. The integral ThunderMax AutoTune system combined with the other system design advantages helps provide a motorcycle with increased throttle response & torque, improved overall rideability & performance, and a smoother & cooler running engine.

Installation is easy and can be done typically within a few hours and the user friendly TMax software is designed to get your initial basemap selected and bike running in no time. The new 18mm wide-band oxygen sensors require compatible oxygen sensors bungs located in your exhaust systems’ head pipes. Most popular aftermarket exhausts include 18mm oxygen sensor bungs and many factory head pipes as well - see model fitment guide for exhaust details.

2. Which ThunderMax fits my year motorcycle and model?

ThunderMax electronic fuel management systems are available for all 2002 & Up EFI-based Harley Davidson motorcycles. Visit our online model selection guide here or download our complete ThunderMax product listing by model here.

3. What is the difference between ThunderMax and other tuning systems or devices?

ThunderMax differs from most other tuning systems and devices primarily because it is a complete performance Engine Control Module (ECM) which replaces the factory or stock module (therefore not limited by the stock ECM’s constraints). Most other systems are called “post-fuel devices” and are basically signal modifiers that adjust spark and/or fuel injector pulse widths. This method is somewhat crude and does not provide a reliable tune for changing ambient conditions like temperature, altitude, engine load, fuel, etc. Newer flash systems basically “wipe out” the memory of the stock ECM and become married to the motorcycle. This type of device still has the limitations of the factory ECM’s electrical hardware and is not capable of wide-band tuning without the use of an external tuning module.

With ThunderMax, you get everything that you would ever need to properly tune your motorcycle now and with potential future upgrades (exhausts, air cleaners, cams, pistons, nitrous, etc.) all with no dyno tuning needed!

4. Do I need new oxygen sensor bungs for my motorcycle’s exhaust system?

ThunderMax utilizes 18mm Bosch wide-band oxygen sensors and requires compatible oxygen sensors bungs located in your exhaust systems’ head pipes. Most popular aftermarket exhausts include 18mm oxygen sensor bungs and many factory head pipes as well – verify your exhaust system is compatible or see model fitment guide for exhaust details. If necessary, 18mm oxygen sensor exhaust bungs can be purchased through our distributors.

5. What are “basemaps” and do you have one with my bike’s configuration?

Think of a basemap as the initial baseline tune for your bike’s configuration (engine displacement, injector size, exhaust, cam, etc.). ThunderMax offers hundreds of different basemaps which have been pre-dyno tuned and can be selected / loaded through the TMax software. You may not always find an exact configuration match, but selecting a basemap with similar type of components (injector size, engine displacement, exhaust) will help you achieve a “faster tune-in” with the ThunderMax AutoTune System.

6. What if I have a problem and need help, how does ThunderMax’s Tech Support work?

If you need technical assistance with your ThunderMax, please feel free to contact our in-house Technical Support Department which is devoted to helping and supporting ThunderMax customers. In order to better assist our customers and to provide the quickest and most accurate means of technical support, our primary communication is via email and utilizes our AutoSupport process. Learn more here.

7. Will the ThunderMax Performance EFI System void my new motorcycle factory warranty?

You want to upgrade your motorcycle with the ThunderMax, but you’re worried about your bike’s new vehicle warranty. By promoting the myth that aftermarket equipment automatically voids warranties, some dealers avoid warranty work. Under the Magnuson-Moss Act, aftermarket equipment which improves performance does not void a vehicle manufacturer’s original warranty.

A dealer must prove that aftermarket equipment caused the need for repairs before he can deny warranty coverage on that basis. To challenge a false claim, ask the dealer to put it in writing. If they refuse to give you a written statement, this is a violation of Federal law. The Federal Trade Commission , which administers the Magnuson-Moss Act, monitors compliance with warranty issues. Direct your dealer complaints to the FTC at (202) 326-3128.

8. Will my factory H-D alarm system work with ThunderMax?

Simply put, yes. ThunderMax is designed to operate with all OEM systems and functions.

9. Will my factory Diagnostic Trouble Codes work?

Simply put, yes. ThunderMax is designed to operate with all OEM systems and functions. ThunderMax also offers additional logs and warranty information which can be viewed in the TMax software interface.

10. Will ThunderMax improve my fuel economy?

In many cases yes; however, this is dependent upon your bike’s configuration and how the AFR targets are set in the basemap. Often times AFR targets are set to richer values than the stock levels in order to gain performance in certain RPM ranges – this may therefore result in moderate decrease in fuel economy. For help with basic tuning adjustments based upon riding style, please review our complete ThunderMax Tuning Manual online.

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