H-D's SE Pro EFI Race Fueler...
H-D's SE Pro EFI Race Fueler is an add-on pot-style device that can be adjusted to add fuel on '96-'04-model bikes, and either add or subtract fuel on '05-later models. The module does not change rev limit or ignition advance.
A generic ECM recalibration or downloadable map is the lowest-cost method for taking the guesswork out of tuning an EFI-equipped engine with performance modifications. What you have to keep in mind, however, is that your engine combination must match the performance modifications addressed by the downloadable map, and even then there are exceptions. If you cannot locate a map that tunes your engine properly, you must consider using either an add-on device or a map-based reprogrammer to get the proper tuning.
Add-On ModulesAn add-on module is a unit that is used in combination with the engine's stock ECM. Most add-on modules are potentiometer-based devices that do not require a computer for adjustment. Some include one or more base maps for certain engine/exhaust system modifications. One unit, the Power Commander by Dynojet, is a programmable map-based device.
An add-on module connects in series between the stock ECM and fuel injectors and modifies the ECM's output signals before the signals reach the injectors. These units are adjusted by using a screwdriver to adjust the potentiometers, or "pots," which adjust rpm transition points (not the ability to increase the rev limit) and air/fuel mixture.
Potentiometer-type devices are generally load-based devices in that they add more fuel at wide-open throttle than at low-throttle settings. Some add-on modules can only instruct the injectors to add fuel or richen the air/fuel mixture, while others can direct the injectors to both add (richen) and remove (lean) fuel. The ability to lean the air/fuel mixture within certain rpm ranges can be important for successful tuning. Pot-based devices are relatively low-cost but have certain limitations as to the range of performance engine modifications they can tune.
Kryakyn's Wild Things FI Controller...
Kryakyn's Wild Things FI Controller is an add-on potentiometer-based device that intercepts and modifies the ECM's signals to the fuel injectors. A screwdriver is used to change the fuel mixture within a specified rpm band. Kryakyn's Controller provides an affordable way for adjusting the fuel curve when the air cleaner, exhaust system, and other components are modified.
Depending on the brand of module, add-on devices include up to four pots, which allow setting between one and three rpm ranges for air/fuel mixture. Basically, you set the transition points for the rpm ranges and then adjust the air/fuel ratio within those ranges. Potentiometer-based devices include the Cobra FI2000, Dynatek F.I. Controller, Harley-Davidson SE Pro EFI Race Fueler, Kryakyn Wild Things FI Controller, Rev Tech Digital Fuel Optimizer (DFO), and the Total Fuel Systems EFI Control Module. Several pot-style devices are currently undergoing design updates to digital where the pot adjusters are reduced to three buttons, a mode select, and plus and minus capability.
The Vance & Hines Fuelpak is another add-on device that connects in series between the ECU and injectors. Instead of using a screwdriver for adjustment, you enter numbers into 18 different "modes" using the display and buttons on the device. Vance & Hines includes a set of numbers for your model and year of Harley, exhaust system, and any ECM updates that you enter into the Fuelpak using the buttons and display. The Vance & Hines Fuelpak includes the ability to either add or reduce the amount of fuel.