Please note that the Twin Tuner is not compatible with 2008 touring models with electronic throttle control (for these models we suggest using the Screamin Eagle^® Race Tuner (SERT) in combination with the Daytona Sensors Twin Scan II+ tuning aid.  

The Twin Tuner allows you to easily adjust your fuel injection to match the requirements of performance parts including camshafts, free flowing exhausts, and low restriction air filters. You can add up to +30% or subtract down to -20% fuel. 

You can use the mode and up/down pushbutton switches to make fuel trim adjustments in the RPM and throttle position ranges required by most applications. The fuel trim value is displayed on a bright daylight readable LED display.

The Twin Tuner also has an advanced mode, where you can use the optional USB Interface and PC Link Tuner software to make precise fuel adjustments. The PC Link Tuner software uses the same RPM rows and throttle position columns as the Dynojet Power Commander. If you have created  Dynojet Power Commander files for your applications, you can enter the same values into our tables. You can make independent adjustments to the front and rear cylinders.

The Twin Tuner works great in combination with the Daytona Sensors Twin Scan II+ tuning aid. You don’t need a dyno for precise tuning. All you have to do is install the Twin Scan II+ and ride the bike around some. You can then copy the air/fuel ratio corrections calculated by the Twin Scan II+ into the PC Link Tuner software.

Download Twin Tuner Instructions

Best Value

We believe that the Twin Tuner offers the best value on the market today. Take a close look at the table below and decide for yourself. 

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Easy Installation

Installation takes only 10-15 minutes and is very easy, with no splicing, cutting, crimping, or bulky interconnections. All access is at the Delphi^® ECM (Buell^® installation is similar). No special tools are required. Just disassemble the ECM connector using a small flat screwdriver as shown below, remove five wires from the ECM connector, insert these wires into our small mating connector, insert five new wires from the Twin Tuner into the ECM connector, and connect one ground wire. The unit is completely encapsulated and impervious to moisture. With a very low profile of only ½” and occupying a fraction of the space required by competitive products, you won’t have a problem finding a place to mount the unit.  

ECM Connector Retainer Removal		ECM Connector Disassembly
ECM Connector Terminal Removal		Completed Wiring at ECM

Basic Tuning

The Twin Tuner has a 10 position rotary mode switch used to select fuel trim parameters to edit, two digit LED display, and up/down pushbutton switches to change the parameter value. Fuel trim parameters are listed in the table below. Note that the rectangular LED to the left of the two digit LED is illuminated for negative values. You can use a small flat screwdriver to rotate the mode switch. You can make parameter changes on-the-fly with the engine running. 

Mode Switch Settings Table

Parameter	Fuel Trim Operating Range
0	Display off – used to prevent inadvertent changes during normal engine operation
1	Idle 750-1250 RPM 0% TPS
2	Low cruise 1250-2000 RPM 2.5-50% TPS
3	High cruise 2000-3750 RPM 2.5-50% TPS
4	Wide open throttle 1250-2000 RPM 50-100% TPS
5	Wide open throttle 2000-2750 RPM 50-100% TPS
6	Wide open throttle 2750-3750 RPM 50-100% TPS
7	Wide open throttle 3750-4750 RPM 50-100% TPS
8	Wide open throttle above 4750 RPM 50-100% TPS
9	Acceleration enrichment (0 = none, 10 = maximum)

The table above shows the engine operating ranges affected by fuel trim values in terms of RPM and throttle position sensor (TPS) values. To properly tune an engine, you need to know what fuel trim values are required. The only practical means of doing so is to use an air/fuel ratio (AFR) metering system based on a wide-band oxygen sensor, either directly mounted in the exhaust or as part of an exhaust sniffer. It is impossible to make accurate adjustments by seat-of-the-pants or reading spark plugs. For models with original equipment oxygen sensors, please download and read the material on page 10 of the Twin Tuner instructions.

If you do not have access to an AFR metering system, you can still make some adjustments based on the following guidelines.

1. Aftermarket camshafts will generally increase manifold pressure (reduce vacuum) near idle. The Delphi speed-density control will compensate with excessive fuel resulting in a very rich idle. Try reducing the idle fuel by -5% to -10% (parameter 0).

2. If the engine runs rough or coughs (backfire through the intake) under part throttle cruise conditions, try adding 10-15% fuel in the RPM ranges where problems are noted (parameters 2 and 3).

3. Performance modifications will generally increase the fuel requirement at wide open throttle. If the engine runs rough or hesitates at wide open throttle, try adding 10-15% fuel in the RPM ranges where problems are noted (parameters 4-8).

4. If throttle roll-on response is poor, try adding some acceleration enrichment (parameter 9).   

PC Link Tuner Software

PC Link software runs under Microsoft Windows 98/ME/XP/Vista. PC Link allows the user to program all the parameters and fuel trim tables within the Twin Tuner. Minimum PC requirement is a 300 MHz Pentium with super VGA display (SVGA with 1024 x 768 pixel resolution). The Twin Tuner connects to the PC by means of an optional USB interface (P/N USB-INTF). This USB interface also works with all Daytona Twin Tec engine controls (ignition and fuel injection systems). The PC must have a free USB port. Before the engine is started, you can download or upload data with PC Link.

You can edit various tables and parameters. 3D tables are used for front and rear cylinder fuel trim. 3D fuel trim tables are accompanied by chart displays that help visualize the data. You can print the data associated with an active table or Twin Tuner parameters by using the appropriate Print command from the File menu. You can open and save tuning files to disk.

Using DynoJet Power Commander Tuning Data

If you have created Dynojet Power Commander files for your applications, you can enter the same values into our tables. A typical Power Commander fuel table is shown below. The TPS columns are the same as used in our tables and the RPM rows are very similar. For intermediate RPM rows in our tables, such as 1,250 RPM, you can enter values approximately in between the values in the Power Commander 1,000 and 1,500 RPM rows. For Power Commander files that have a single fuel table, use the same values for both cylinders with the Twin Tuner.   

Tuner Log Software

When the engine is running, you can display real time engine data on an instrument panel type screen by using the View Real Time Data command on the View menu.

You can also check proper operation of the throttle position sensor (TPS) when the run/stop switch is on (engine not running). Rotate the throttle through the full range of motion. The TPS% value should go from zero to 100%.  

Real time engine data is displayed on an instrument panel type layout with a round tach gauge and bar graph type gauges for all other parameters. Status messages are displayed in a separate window.