Transcript
DIRECT LINK FLASH TUNER Installation and User Manual
Rev 3.0 This Guide is intended to answer basic Direct Link tuning questions and to act as a Quick Start Guide. It is not intended to be encyclopedic on the tuning process - only to answer basic questions about Direct Link. This Guide will give some example tables that have been proven to work in the past, but the tuner/dealer is ultimately responsible for the final tune on any bike.
INTRODUCTION ................................................................................................................................................................... 3 HOW IT WORKS ................................................................................................................................................................... 3 ABOUT THIS MANUAL.......................................................................................................................................................... 3 1. SETUP AND INSTALLATION............................................................................................................................................... 4 1.1 WHERE TO GET THE SOFTWARE .......................................................................................................................................... 4 1.2 INSTALL DIRECT LINK FLASH TUNER ..................................................................................................................................... 5 1.3 RUN DIRECT LINK FLASH TUNER .......................................................................................................................................... 5 1.5 CONNECT USB CABLE ...................................................................................................................................................... 6 1.6 POWER UP THE DIRECT LINK FLASH TUNER ............................................................................................................................ 7 1.7 POWER UP TO AUTOMATICALLY INSTALL DRIVERS.................................................................................................................... 7 1.8 UPDATE THE SOFTWARE ................................................................................................................................................... 8 1.10 CONFIRM COM PORT FOR COMMUNICATION .................................................................................................................... 10 1.11 TROUBLE-SHOOTING COM PORT ISSUES ........................................................................................................................... 12 2. TOOLBAR ICON DESCRIPTIONS ...................................................................................................................................... 13 2.1 MAIN MENU ............................................................................................................................................................... 13 2.2 TAB MENU .................................................................................................................................................................. 13 2.3 DIRECT LINK TOOLBAR BUTTONS ....................................................................................................................................... 14 3. KEY FEATURES................................................................................................................................................................ 15 3.1 CREATING A BACKUP ...................................................................................................................................................... 15 3.2 LOADING A MAP ........................................................................................................................................................... 17 3.3 IMPORTANT TABLES ....................................................................................................................................................... 19 3.3.1 VE Table ............................................................................................................................................................ 19 3.3.2 Spark Table ....................................................................................................................................................... 20 3.3.3 AFR Ratio Table ................................................................................................................................................. 21 3.3.4 Cranking Fuel .................................................................................................................................................... 22 3.3.5 Idle Table .......................................................................................................................................................... 23 3.3.6 IAC Table ........................................................................................................................................................... 24 3.3.7 Acceleration Table ............................................................................................................................................. 25 3.3.8 Decell (Deceleration) Table ................................................................................................................................ 26 3.3.9 Closed Loop ....................................................................................................................................................... 27 3.3.10 Warm-up Fuel table......................................................................................................................................... 28 3.4 ADDITIONAL CHECKS ...................................................................................................................................................... 29 3.4.1 Knock Sensor ..................................................................................................................................................... 29 3.4.2 Engine Parameters ............................................................................................................................................ 29 3.4.3 Calibration Note ................................................................................................................................................ 30 3.4.4 Throttle grip ...................................................................................................................................................... 31 4. PROGRAM THE CALIBRATION INTO THE ECU ................................................................................................................ 32 4.1 SAVE ORIGINAL CALIBRATION ........................................................................................................................................... 32 4.2 PROGRAM ................................................................................................................................................................... 33 4.3 PROGRAMMING STATUS ................................................................................................................................................. 34 5. HOW TO SAVE THE MODIFIED CALIBRATION ................................................................................................................. 35 5.1 SAVE AS ...................................................................................................................................................................... 35 5.2 CALIBRATION INFORMATION ............................................................................................................................................ 36 6. HOW TO CHANGE UNITS ................................................................................................................................................ 36
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6.1 OPTIONS ..................................................................................................................................................................... 36 7. MONITOR REAL-TIME DATA (GAUGES/METER DISPLAY)................................................................................................ 37 7.1 MONITOR DATA ........................................................................................................................................................... 37 7.2 CHANGE CHANNELS ....................................................................................................................................................... 37 7.3 CHANGE VISIBLE PARAMETERS ......................................................................................................................................... 38 7.4 TURN IGNITION TO RUN .................................................................................................................................................. 39 7.5 COMMUNICATE ............................................................................................................................................................ 39 8. MONITOR REAL-TIME DATA (STRIP CHART DISPLAY/METER DISPLAY)........................................................................... 40 8.1 VIEW DATA ................................................................................................................................................................. 40 7.2 CHANGE CHANNELS ....................................................................................................................................................... 41 7.2.1 Channel Display ................................................................................................................................................. 42 7.3 TURN IGNITION TO RUN .................................................................................................................................................. 43 7.4 COMMUNICATE ............................................................................................................................................................ 43 8. AUTO-MAPPING ............................................................................................................................................................ 44 8.1 SELECT STRIP CHART ...................................................................................................................................................... 44 8.2 LOGGING DATA WITH A DYNO .......................................................................................................................................... 44 11.3 LOGGING DATA WITH MOBILE DYNO ............................................................................................................................... 46 GLOSSARY.......................................................................................................................................................................... 50
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Introduction The Direct Link Kit will provide the tuner with the tools and necessary data to maximize the potential of the installed upgrades. The system is designed for Harley-Davidson® Fuel Injection equipped motorbikes.
How it Works The ECU is basically a calculator that sends signals to the injectors. The sensors include the temperature of the motor (Harleys head temperature sensor), outside ambient temperature and pressure (altitude), throttle position (TPS), engine speed (RPM) and load (KPA or MAP, manifold absolute pressure). The newer models, (2008 and later), also have a narrow band O2 sensor and actually run in ‘closed loop’ when you tell it to. The ECU combines all data gathered by the above mentioned sensors and compares it to the ‘scribed’ maps that have been set up at the factory and makes adjustments so that the engine works at its best given the circumstances.
About this Manual The Direct Link User’s Guide is a comprehensive guide that contains procedures you will need in order to work with this software. This manual is organized by chapters to assist novice users with getting started. Many topics covered in this manual are also covered in the help menus available in the program itself. This Guide/Manual has been written thinking that not only professionals will use it, but also non-professionals. That is the reason it is written in a non-technical way.
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1. Setup and Installation 1.1 Where to get the Software Insert the CD-ROM from TechnoResearch Inc. into the DVD/CD-ROM drive of the computer…
OR download from our website (www.technoresearch.com, go to Support > Downloads).
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The first download link will be for the software. This is where you can also find manuals and guides.
1.2 Install Direct Link Flash Tuner After auto-run, press install and follow the installation prompts.
1.3 Run Direct Link Flash Tuner With the red or blue USB key plugged in to the computer, double-click on the Direct Link icon on the desktop to run the program. This will install the necessary driver for the USB hardware key.
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1.5 Connect USB Cable Connect the USB computer cable (shown below at left) to the Vehicle Communication Module. The module is shown below, with the USB port on the right side of the metal endplate. Connect the other end to the PC’s second USB port.
VCM-TR1
VCM-TR3
NOTES: • The supplied USB Hardware Key with this software is for use on a single vehicle only. When the USB Hardware Key is used to program a vehicle, it will be permanently attached to that vehicle, and cannot be used on any other for programming. •You can use any key, empty or used, to start and use this software. Only when ‘programming’ will the software check that the key is empty and lock it to THAT ECU. If the key has been used before, the software will check that the key will match the ECU. If not, the software will be closed. •NEVER plug in multiple hardware keys. For example: do not plug in a Direct Link key and a Centurion key at the same time!
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1.6 Power up the Direct Link Flash Tuner Connect the Vehicle Communication Cable to the DB-15 port on the other end of the Vehicle Communication Module (shown below). Connect the other end to the motorcycle’s data link connector. If you cannot locate your bike’s data link connector, see below or please consult your motorcycle user manual.
Location of Data link connector: Touring models: Underneath the right side cover. (2008-2012 Underneath the left side cover) Softail models: Underneath the seat. Dyna models: Underneath the left side cover. Sportster models: Underneath the left side cover. VRSC: Underneath the front side neck cover.
1.7 Power up to Automatically Install Drivers The VCM is powered by the battery of the motorcycle. Make sure the ignition is ON and the RUN switch is ON. The light on the VCM should be lit. This will cause the software to search for and install the cable drivers.
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1.8 Update the Software After the Direct Link software is installed, run the updater to get the latest program versions including the calibrations and the manuals. Click ‘Updater’ in the bottom right corner:
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Select ‘Install New Release’ and let the Updater run to completion.
1.9 Disclaimer/Language Selection After the update is finished, open the main menu again (double-click DL Icon) and click ‘Accept’ to agree to the terms of use and select a language preference to launch to software.
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The software will open to the Programming screen. This screen is where you will do a lot of your work. You should ‘play’ with this screen and practice opening and closing editing tables and connecting to the motorcycle. Each table you edit will change something on the motorcycle and you will always program the ECU from this screen.
1.10 Confirm COM Port for Communication Under ‘Communication’, select ‘Port Setting’.
Important: If the Direct Link hardware (VCM) is not powered, then the correct COM Port will not appear (indicated by an illuminated LED). To rectify, press ‘Cancel’ and power the Direct Link hardware by turning on the ignition switch and making sure the engine stop/run switch is in the RUN position. Once the LED light is on, the Direct Link hardware is on, select ‘Communication’ and ‘Port Setting’ again to select the correct COM Port.
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Either select the COM Port manually using the arrows or click the box to use USB:
Click ‘OK’ and then test connection by clicking ‘ECU Info’ on the programming screen. If connection is successful, the ECU Info section will populate with the bike’s current information:
If connection fails, see the next step for trouble-shooting COM port connection issues.
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1.11 Trouble-shooting COM Port Issues If the COM port cannot be selected and checking the USB box does not allow connection, it means that the driver for it was not correctly installed when installing the software. Go to the computers Control Panel, select ‘Hardware and Sound’, select ‘Device Manager’. Expand ‘Other Devices’ or ‘COM Ports’ to locate the serial converter or key. If the COM port is not showing, the yellow triangle icon will appear:
IMPORTANT: This means that the driver was not correctly installed when installing the Centurion U/UE/M/S software. When you right click and select ‘Update Driver Software’, you can manually browse and point the search at your CD/DVD drive if the software CD is in, OR search automatically and the files should be pulled.
After the correct device driver is installed or updated, the window will look like this:
Go back to the ‘Port Setting’ window in the software and make sure the corresponding number is selected—in this case, COM14 OR check the box for USB. Test for connection again by selecting ‘ECU Info’. 12
2. Toolbar Icon Descriptions 2.1 Main Menu The Direct Link main menu offers a variety of commands. Below the main menu are the Toolbar Buttons, which offer quick access to the most often used commands.
2.2 Tab Menu File Menu: Commands to open, export, backup or save a file, close an active window, and quit the program Edit-Table: Access to editable tables and engine settings View: Contains commands related to what mode you are viewing Communication: Commands for connecting, disconnecting, and programming Options: Trace and data record settings, access to Mobile Dyno, settings to change units and colors Help: Displays a variety of help commands
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2.3 Direct Link Toolbar Buttons The toolbar buttons allow one-click access to the most frequently used commands.
Open Calibration
Open Data Log
Save As…
Print
Reflash
Gauges/Meters
Strip Chart
PVI
Connect
Disconnect
Recording ON/OFF
Channels/Mode
Auto map/Mobile Dyno
Front & Rear Spark Table
Front & Rear Fuel Table
AFR Table
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3. Key Features 3.1 Creating a Backup Always save the original calibration before programming the new calibration. That way, the motorcycle can be restored to stock at any time.
Precautions: During the backup and programming, the ECU must be powered correctly. Therefore, we recommend removing the LIGHT fuse and using a charger to be sure that the voltage is correct. With the ignition switch on and the engine stop switch in the RUN position, click ‘Backup Map’. This will back up the original map from the ECU so that, at a later date, the motorcycle can be restored to stock if needed.
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Select a location and name for the Backup Map and click on ‘Save’
Direct Link will now read and save the original bike map. After the status bar has reached 100, check for the green PASS to ensure that all operations have concluded successfully.
Note: Do not disconnect the USB Hardware Key. This could damage the key. 16
3.2 Loading a Map Before loading a map, check what map is in the motorcycle ECU by pressing the button ‘ECU Info’. The Application # text box will show the correct map model (105, 127, 176, etc.)
Find the map best suited to load (based on application #) by opening a calibration via File > Open Calibration > Modified or click the ‘Open Calibration’ icon. This will open a file selection window. (The Application # mentioned is usually in the end of the map file name.
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Navigate the folders by year/model, select a map and click ‘Load’. Once loaded, the Calibration Information can be reviewed and compared with that of the ECU.
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3.3 Important Tables (Check before first flash) The following tables can be found under the ‘Edit-Table’ drop down, or by using the toolbar buttons shown:
3.3.1 VE Table
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3.3.2 Spark Table
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3.3.3 AFR Ratio Table
The values in the AFR (Air-Fuel Ratio) table are calculations that the ECU uses to determine the injector pulse width. The AFR does not actually change. This is the main fuel table that the ECU will try to achieve. The tuning process changes the VE (Volumetric Efficiency) tables so that the live AFR data is as close to AFR table. You can, and should, change the VE’s on each cylinder separately. They each have different requirements and the fuel injectors may not be matched for flow. There are (2) methods to accomplish this—Set the AFR Ratio Table in open loop but close to the final Target values. The other method is to set all of the values to the same constant (13.2 -13.5). Once the values are in place, click on the Apply button to apply the changes, then the ‘OK’ button to conclude the modification.
Note: When working on the ‘closed-loop’ models, changing the AFR value to 14.0 or below disables closed-loop operation which makes VE table tuning possible. 21
3.3.4 Cranking Fuel Found under ‘Edit-Table’ drop down menu. Make sure to check this table. The cold temperature numbers should have more fuel than the hot temperature numbers. Double click on an mSec cell and use the up and down arrow to adjust.
The values above a temperature of 233F may have to be adjusted up or down to get the bike to start quickly. Click OK. See this example of a typical Cranking Fuel table:
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3.3.5 Idle Table Found under ‘Edit-Table’ drop down menu. Make sure to check this table. Double click on an RPM cell and use the up and down arrow to adjust. Remember to let the engine get to working temperature before making any changes. Click OK. See this example of a typical idle table:
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3.3.6 IAC Table Found under ‘Edit-Table’ drop down menu. Make sure to check this table. This table may need to be adjusted while tuning to make sure bike is idling up on startup, and when at operating temperature, the idle is stable. Check live data and verify that the actual stepper counts are not lower than the programmed stepper counts. The actual Steps should be the same or slightly lower than the programmed values. Double click on a STEPS cell and use the up and down arrow to adjust. Click OK. See this example of a typical IAC Table:
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3.3.7 Acceleration Table Found under ‘Edit-Table’ drop down menu. Make sure to check this table. The accel table needs to be adjusted during tuning so the bike will have crisp response when blipping the throttle and no black smoke comes out of the exhaust. Double click on a STEPS cell and use the up and down arrow to adjust. Click OK.
TIP: Create a table that lists the changes in calibrations that have been modified just in case you want to go over your own work before saving.
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3.3.8 Decell (Deceleration) Table Found under ‘Edit-Table’ drop down menu. Make sure to check this table during tuning if decell popping is occurring. This table allows the removal of a small amount of fuel during a decrease in throttle position, or during a decrease in manifold pressure. This fuel gets subtracted from the base pulse width calculation. •Larger values increase the fuel removed. •Smaller values decrease the fuel removed.
Double click on a STEPS cell and use the up and down arrow to adjust. Click ‘OK’.
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3.3.9 Closed Loop Found under ‘Edit-Table’ drop down menu. This table can be left alone for tuning, as the AFR Table has been set so the bike will always be in open loop and not be using the factory Oxygen sensors. Only when the AFR table is at 14.6 will this table be active and used. There are (2) types of closed loop systems now. The older bikes use closed loop biasing and the new bikes do not. The new bikes can be set from 14.3 - 14.6 for closed loop. The old bikes with the bias table have the AFR value or millivolt setting centered at 450volts. Setting this table to 680 will yield something like 14.5-14.6 AFR Value. You cannot set this mv value much higher, as the O2 sensor will not switch properly and will drive the fuel rich. The sensor needs to switch around a center point.
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3.3.10 Warm-up Fuel table Found under ‘Edit-Table’ drop down menu. Make sure to check this table. This table needs to be minimized as much as possible so gas is not being wasted on warm-up. Double click on an AFR cell and use the up and down arrow to adjust. Click OK. See this example of a typical Warm-up Fuel Table:
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3.4 Additional Checks (Check before first flash) The following tables can be found under the ‘Edit-Table’ drop down menu: 3.4.1 Knock Sensor This should be turned on when the timing table is being adjusted and click ‘OK’ to save.
3.4.2 Engine Parameters The settings for Engine size and injector size should be set to match what the engine really is. These parameters may need to be adjusted to alter the VE tables off of maximum values. Try to leave the cubic inch values matched to the motor and move the injector values to allow the VE tables to be in spec.
Click on a parameter and use the arrows to adjust. Click ‘OK’ to save.
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3.4.3 Calibration Note It is a good idea to detail what modifications the engine has—CAMS, pipes, air box, etc. (It is recommended that ‘First ECU flash’ is noted when applicable).
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3.4.4 Throttle grip This table sets the maximum throttle valve opening at a specific throttle grip setting and RPM. This table needs to be set before any tuning is done.
All of the tables have been checked and it is time to flash the ECU for the first time. We will be flashing many times once the tuning of the VE tables and the adjustment of the spark tables starts. The first flash has to be done to register all of the changes just made. After this we start the tuning process.
Note: A re-flash is always necessary for any changes to take effect.
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4. Program the Calibration into the ECU For all practical purposes, this describes what to do on a relatively stock or only slightly modified motor (cams, pipes, air breather and/or heads).
4.1 Save Original Calibration After backing up the original map (see 3.1) and loading the one you will be programming, start to tune the calibration.
Note: Open the ‘Edit-Table’ menu and click on ‘Engine Setting’. The displacement can be set if you’ve changed that and the injector size. This is very handy because if the injectors are changed later, the software can input the new size and it will compensate for larger injectors or a big bore kit.
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4.2 Program Go to ‘Communication’ menu and select ‘Program’ or just click ‘Program’ button to upload new calibration into the ECU.
Note: Do not disconnect the Direct Link key. This could damage the key. This will load a map into the system. The processing status is indicated on the progress status bar.
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4.3 Programming Status At the end of the programming mode, a ‘PASS’ or ‘FAIL’ message will be displayed.
FAIL: If during the programming an error message/Fail message appears, disconnect the ECM/ECU for 30 seconds, then reconnect, and begin programming again. Please also double check the wiring and adaptors being used. (Note: If this message persists, remove all the fuses and relays from the fuse box of the bike except the ECM/ECU and ignition fuses. Reprogram the ECM/ECU and put back all the fuses.) PASS: After successfully programming the ECU, follow the prompt instructing that the ignition be turned off for 15 seconds and then turned back on.
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5. How to Save the Modified Calibration 5.1 Save as It’s recommended that you save as you progress through tuning so you can back-track at any point if need be. Click the ‘Save as’ icon or go to ‘File’ menu and select ‘Save As’.
Note: Always save the original calibration before programming the new calibration. That way, the motorcycle can be restored to stock at any time. Type a new file name. Click ‘Save’.
TIP: Name the file a special name so you don’t have any problems finding and opening the new modified file. You should always retrieve your stock tune and save it before you make any changes so you can go back to the stock tune in case any errors were made.
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5.2 Calibration Information ‘Calibration ID’ and ‘Calibration Note’ can be edited or modified. Click ‘OK’ when finished.
6. How to Change Units 6.1 Options Go to ‘Options’ menu and select ‘Units’. Select the preferred unit. Click ‘OK’.
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7. Monitor Real-time Data (Gauges/Meter Display) 7.1 Monitor Data Monitor the Real-time data with Gauges/Meters display. Go to ‘View’ and select ‘Gauges/Meters’ or just click ‘Gauges/ Meters’ icon.
7.2 Change Channels To change the visible data, go to ‘Options’ and select ‘Channels/Mode’ (or just click ‘Channels/Mode’ icon).
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7.3 Change Visible Parameters There are six channels. Click the gray square button to change the visible parameter or select ‘Default’.
Customize any parameters to display. Click ‘OK’.
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7.4 Turn Ignition to Run Turn on the ignition switch and make sure the engine stop switch is in the RUN position.
7.5 Communicate Go to ‘Communication’ and select ‘Connect’ or just click ‘Connect’ icon.
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8. Monitor Real-time Data (Strip Chart display/Meter Display) 8.1 View Data Monitor the Real-time data with Strip Chart display. Go to ‘View’ and select ‘Strip Chart’ or just click ‘Strip Chart’ icon.
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7.2 Change Channels To change the visible data, go to ‘Options’ and select ‘Channels/Mode’ (or just click ‘Channels/Mode’ icon).
Channels can be customized by selecting the drop down next to each parameter, the whole parameter can be turned on or off, or all channels can be set to ‘Default’. NOTE: For optimal data read-out and tuning/auto-mapping, TechnoResearch recommends selecting ‘Default’.
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7.2.1 Channel Display Up to sixteen channels at a time can be displayed. To increase or reduce the number of channels, click the ‘on/off’ switch. Select either Parallel or Overlay view mode. ON: Show the selected channel. OFF: Hide the selected channel.
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7.3 Turn Ignition to Run Turn on the ignition switch and make sure the engine stop switch is in the RUN position.
7.4 Communicate Go to ‘Communication’ and select ‘Connect’ or select the ‘Connect’ icon.
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8. Auto-mapping Connect the hardware and open the Direct Link software. Follow steps 3.1-3.2 for saving and loading the map. Program the ECU.
8.1 Select Strip Chart Select the ‘Channels/Mode’ button. Choose ‘Default’. The software will not continue if these channels are not selected. NOTE: Make sure the starter map you want is loaded and programmed before continuing.
8.2 Logging Data with a Dyno While in Strip Chart mode, click ‘Connect’ and wait for the bike to connect.
Select the Auto Map icon.
Select ‘Dyno’ and click ‘OK’.
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Click ‘Start Session’.
When finished logging, click ‘End Session’. A prompt will open—click ‘OK’ to automatically load the log. TIP: To open previous Logging Sessions click the ‘Open Log’ icon (
), select the run and click ‘Load’.
Click ‘Create Map’.
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Choose the tables to be modified and the O2 sensors that were used.
Make changes to the VE Tables and click ‘OK’ when finished. To save, click the ‘Save’ icon ( to the re-flash screen (
). Now go back
), open the new calibration and program it to the ECU.
NOTE: Make sure to BACKUP the original calibration so the motorcycle can be restored back to stock if necessary.
11.3 Logging Data with Mobile Dyno Select the ‘Channels/Mode’ button. Choose ‘Default’. The software will not continue if these channels are not selected. Select the Auto Map icon.
Select ‘Mobile Dyno’ and click ‘OK’.
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Click ‘Begin’.
A prompt will ask to configure the VCM. Select ‘Yes’. Unplug the VCM from the computer and the motorcycle (the VCM’s power source). The next time the box gets power, it will begin recording. When ready to ride, connect the box to the bike again. It will now begin to log data (up to ~15 minutes worth). The green LED on the VCM will blink, signifying that it is recording.
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When finished logging, turn the bike off for at least 15s. Connect the VCM back up to the computer and turn the bike back on. Select ‘End Session’.
The log file will automatically download and then load. Click ‘Create Map’.
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Choose the tables to be modified and the O2 sensors that were used.
Make changes to the VE Tables and click ‘OK’ when finished. To save, click the ‘Save’ icon ( to the re-flash screen (
). Now go back
), open the new calibration and program it to the ECU.
NOTE: Make sure to BACKUP the original calibration so the motorcycle can be restored back to stock if necessary.
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Glossary
ECM/ECU (Electronic control module/unit): This is the brain of the motorcycle; it makes calculations based on inputs coming from sensors mounted all over the engine.
WOT (Wide open throttle): The maximum opening of the throttle valve. AFR (Air fuel ratio): The relationship of parts of fuel to the parts of air. 13.0(air) to 1(fuel) usually makes the best power, and 14.6 is considered ‘perfect’ air fuel ratio. This would be the AFR to get an ideal burn (theoretically). This would be at perfect atmospheric conditions and temps, with a perfect atomization which is almost impossible.
VE (Volumetric efficiency): This is the most important part of tuning. If the computer ‘knows’ the volumetric efficiency, it can decide how much fuel to add to run best. It is how you tell it to add or subtract fuel and is one of only two variables you can adjust to get the AFR correct. The O2 sensor will aid in your adjustments.
MAP (Manifold absolute pressure): These sensors measure barometric absolute pressure in the intake manifold. By calculating the mass of the air going into the engine, air temperature, and the rotations per minute of the engine, the engine’s ECU can determine the density of the air flowing into the fuel mixture. The ECU can then adjust air flow or fuel flow.
CKP or CP (Crank position sensor): This sensor tells the ECM when to fire and inject fuel depending on how fast the engine is running in revolutions per minute.
IAT (Intake air temperature): The ECM calculates how dense the air is from this input. ET (Engine temperature): The ECM uses the signals from this sensor to determine if the engine is at operating temperature, or warming up.
Fuel Pressure Regulator: A mechanical device usually operated by vacuum form intake manifold that controls fuel pressure. It returns excess fuel from the fuel pump back to the fuel tank.
Fuel Injectors: The fuel injectors are electric valves that open and close to deliver fuel in spray form to the cylinder. They are controlled by the ECM to precisely deliver the correct amount of fuel at every engine speed, or RPM, and any given load. The time of injection is also known as the injector ‘pulse width’ and is measured in milliseconds. Injectors are rated by their flow rate – such as in gm/sec, l/hr or grams per second.
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Electric Fuel Pump or Fuel Pump: A 12-volt high-pressure fuel pump, usually located in the fuel tank, but it can be located outside as well. It supplies pressurized fuel to the fuel injectors.
IAC (Idle air control): An electric valve that’s threaded to open and close as needed. This lets air into the engine for start-up, and idle operation when throttle valve is closed.
Closed Loop injection system: This circuit has 2 Oxygen sensors. The information on the difference of how much is coming out of the cylinder is relayed to the ECM and then adjusts the amount of fuel injected by shortening or lengthening the time the injectors are open.
O2 Oxygen sensor (sniffer): Tells the ECM how much oxygen is in the exhaust mixture so as to adjust to have the correct mixture.
RPM (Revolutions per minute): Used to measure engine speed. TPS (Throttle position sensor): You will be dealing with percentages (0 to 100).
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