Using TuneBoy Tune Editor (TuneEdit) with Dynojet's Tuning Link

Introduction

The DynoJet Tuning Link software is a program that automates the tuning process for motorcycles fitted with a PowerCommander fuel modifier.

This document is intended to show you how you can take advantage of this tool to create a custom fuel map for your motorcycle without having a PowerCommander fitted to the bike.

How the PowerCommander PCIII works

The PCIII connects between the ECU and the injectors, the injectors are no longer under the control of the ECU but instead are driven from the PCIII. The PCIII also connects to the throttle position wire from the throttle position sensor to the ECU.

When the ECU attempts to open the injector it does not open the injector, instead this signal is picked up by the PCIII and it opens the corresponding injector.

When the ECU closes the injector the PCIII will record the time that the injector was open and apply a plus or minus trim.

The amount of trim applied by the PCIII is determined by looking up the PCIII trim map.

The PCIII trim map is divided into 500 RPM increments and has nine throttle increments (0,2,5,10,20,40,60,80,100).

How Tuning Link works

The Tuning link software (Running on the Dyno PC) talks to the PCIII via a serial cable. The first thing the Tuning link operator does is read the current trim map from the PCIII. This map is then displayed on the Tuning link screen.

Also displayed on screen are the current revs (from the inductive pickup), the throttle position (from the PCIII) and the air fuel ratio from the dyno O2 sensor.

The Tuning link software has a target air fuel ratio; this is normally set to range from 13.5 to 13/1, depending on throttle position.

The dyno operator now selects a starting point in the map displayed on screen (for example 80% throttle and 2500 RPM), they then hit the start run button on the dyno. At this point the dyno will hold the revs of the bike down to 2500 until the throttle position is held steady at 80%, it then releases the load to allow the engine revs to increase.

As the revs increase the software samples the air fuel ratio at the 500 RPM increments, at the end of the run it displays a graph showing the air fuel trace and modifies the PCIII map in each location (for the selected throttle, 80% in this case) by the percentage required to bring the air fuel reading down or up to the target.

As an example, if the target was 13/1 and the O2 sensor showed 15/1 the trim required should be 15%.

(100 * 15) / 13 = 115

This process is repeated for each of the nine throttle positions.

The process can also be repeated for each throttle position to fine tune the map locations.

The good thing about this tuning process is that it does not hold the bike at constant revs; instead it lets the revs climb as they do when you ride the bike.

How to use Tuning Link with TuneEdit

To use this you need a Laptop or PC with two serial ports, the first is connected to the bike using the TuneBoy cable, The second is connected using a null modem cable to the serial cable on the dyno that normally connects to the PCIII.

When you start the TuneEdit software you will need to use the Start PowerCommander Emulation option under the Tools menu.

Now if you select the Fuel trim map you will see a screen like the following.

The rows with the red highlight are the rows that will correspond to the PCIII throttle increments. These can be changed using the P key to select/deselect a row, only nine rows can be selected at once as the PCIII only has nine rows.

Once you start doing the runs with the Tuning Link software you should not change the rows or you may get incorrect results, if you want to change the rows you should first change them in TuneEdit then start the Tuning Link software.

It is important that the trim map is all zeros at the beginning of the tuning link session, otherwise things can get a little confusing.

If the map in your bike has two trim maps (Aprilia and EH motorcycles) you can also change the focus for the Tuning link to the second trim map by selecting that trim map and hitting the P key once. Make sure that the exhaust gas probe is in the correct header pipe if you plan to trim the rear cylinder.

The next step is to make sure that the map in the bike and the Tuning link software both have the same air fuel targets, Get the dyno operator to change the air fuel targets in the Tuning link software to 13/1 for all throttle zones.

Now select the A/F 1 table and change all targets to 13/1 (as shown in the next screen shot)

The same should be done for the A/F 2 table.

At this point you should save the map with a new name then download the map to the bike, this is to make sure that the bike is using the values in this map, remember that changes to the Sagem system require a download to the bike to take effect.

Now your dyno operator can start using the Tuning link in the same manner outlined above. This only works for roll on tuning as outlined above.

When the throttle position is displayed on the Tuning link screen it will be coming from the TuneEdit program, The TuneEdit program will interpolate the throttle position values from the Sagem and send out the correct value to match the rows highlighted in the trim map to the throttle rows for a PCIII map.

IE. (In the trim map example shown above)

By doing this it makes sure that the throttle points that the Tuning link software gets you to hold will match the points selected in the TuneEdit trim map.

At the end of each Tuning link throttle run the resulting trims will be placed in the corresponding rows in the TuneEdit trim map.

This map shown below shows the trim values in place after doing a 100,80,60,40,20,10 and 5% throttle runs in the Tuning link.

The TuneEdit software interpolates the RPM points to match the RPM points in the TuneEdit map, it does this because the recommended changes from Tuning link are for 500 RPM intervals and the Sagem maps are not in 500 RPM intervals.

You can only do one run for each throttle position, after this you must download the map to the ECU otherwise subsequent runs will be incorrect as it will think it already has a trim applied but the trim is not applied until the map is loaded into the ECU.

We would recommend that the map be saved after each set of Tuning link runs, we also suggest that you commit the trims before you start and repeat runs.

When you commit the trims you need to hit the Get map button on the Tuning link software, otherwise it will still have the map with trim values.

After you have completed your tuning session you will have a map that perfectly matches your motor. Not only that but you will have a map where the air fuel targets that the ECU is aiming for are what you are getting at the exhaust. This point is important because it now means that you can adjust the A/F 1 and A/F 2 maps to change the air fuel at the exhaust. In this way you can have different maps for power and economy depending on the type of riding you plan to do.

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