What is the best control unit for remapping Harley-Davidson fuel injection?

• Basic enrichers

In this section, we find devices that are inserted between the ECU and the injectors. These devices intercept the signal from the ECM and increase or decrease it, varying the injector opening time and, therefore, the amount of fuel delivered.
Its adjustment is quite crude and is usually done using manual potentiometers or buttons. Three RPM ranges are typically set: low, medium, and high.
The Wiseco Controller would belong to this category,

Arlen Ness's Big Shot,

Cobra FI2000 ,

the Techlusion TFI and all the variations that this latest manufacturer makes for different brands.

We will also include in this section the Nightrider or Namz Lambda probe enrichers .

The only advantage of these enrichers is that they're relatively inexpensive, but when comparing the results on a dyno, it's very difficult to tune the engine properly. However, it's always better to install them than to run without anything else.

• Advanced enrichers

In this section, we'll cover devices that operate basically like the previous ones, intercepting and varying signals from the ECM. However, in this case, they interact with more sensors, learning data such as throttle position, intake manifold vacuum, etc., and varying their mode of operation based on this data.
Most of these advanced modules can be programmed via a personal computer and include software for modifying the various ignition, fuel, and VE (volumetric efficiency) maps.
Their price is significantly higher than that of basic enrichers and requires greater knowledge of EFI system operation for proper optimization.
Dynojet's Power Commander kits would fall into this category,

Vance & Hines Fuelpak ,

SLM from Accel, Twin Tuner from Daytona,

Dyna 2000 by Dynatek, Precision Engine by Revolution, etc...
They generally allow the download of different maps from the Internet, appropriate for the components of our motorcycle, and in recent years, Autotune kits that complement them have become more widespread, allowing these maps to be adjusted practically to the millimeter without the need for extensive knowledge and without the need for a dyno.

• Native software modifiers

The last group of injection "control units" includes those devices that do not intercept or modify signals, but are capable of rewriting the original ECM code, reprogramming it natively.
These are basically interfaces that allow a personal computer to communicate directly with the motorcycle and adjust its parameters and tables (idle RPM, fuel, ignition, constants, temperature management, etc.). Their price is on the higher side, and the software that accompanies these products is highly advanced, so they require a thorough understanding of EFI systems to get the most out of them.
It's also true that in recent years, manufacturers have been making efforts to make them easier to use, and almost all of them now offer the ability to perform active learning (Autotune) without the need for auxiliary devices (using the original Lambda sensors) and with astonishing resolution. Some even have touchscreens or direct connection to a mobile phone, allowing you to view engine constants and values (speed, RPM, temperature, fault codes, map changes, etc.) on the screen.
Another of the software's strengths is its diagnostic capabilities, making it a useful tool.
In this last category we would have the Screamin' Eagle Super Tuner,

the TTS Mastertune ,

the Dynojet Power Vision ,

Superchips Watcher

or the Vance & Hines Fuelpak FP3 .

Special mention should be made of devices with a switchboard included, such as Thundermax ,

Daytona TCFI

or the S&S VFI.

These kits include their own ECM and due to their price and complexity are only recommended for highly modified engines or projects where an original ECU is not available.

Drawing conclusions
Now that you have the basic knowledge of the different options, it's simply a matter of assessing which product is most suitable based on your type of motorcycle, your goals, and your available budget. In any case, it's essential to carefully read the manufacturer's instructions and recommendations and understand what you're going to do before starting the installation.
This way you'll feel comfortable using it and be able to take full advantage of its features.
As always, remember that in most countries, modifying the fuel injection system is not permitted for vehicles operating on public roads...

Frank Burguera

#harleymechanics