Once you have finished with the physical installation of your Holley Dominator MPFI system, including the throttle body, ECU, wiring harnesses, required sensors, and fuel system components, you will probably take a deep breath (you’ve earned it) and ask yourself, “OK, how do I get this thing to run?”
What follows is a step-by-step guide to putting all that wonderful hardware to good use.
You have two choices: build a base tune from scratch or tweak one of the base tunes Holley has provided.
If you’re an advanced tuner, you may elect to build a base tune from scratch. You really should know your camshaft profile, etc. before proceeding here. To tweak one of the base tunes follow Holley’s section 3.3.2, “Creating an Initial Calibration” in the Step-By-Step Beginners Tuning Guide (found in the Help menu). The process for building a base tune from scratch is explained in section 2.2.2, “Creating an Initial Calibration” in the Experienced User Tuning Manual (also found in the Help menu).
Holley has included a number of base calibrations that can be loaded into the ECU so why not take advantage of that? We did. You can find a complete listing of the included base calibrations in the Help menu (Help > Contents > Base Calibration Information). Each has a brief description, and they are separated into TBI and MPFI base calibrations.
The Holley software stores tunes in Global Folders. A Global Folder has the following discrete files at a minimum:
• Fuel File (.fuel)
• Idle File (.idle)
• I/O (input/output) File (.io)
• Sensor File (.sensor)
• Spark File (.spark)
• System File (.system)
Each of these files is created (or tweaked) by the user in the software by choosing the appropriate icon in the title bar.
Although the software has a seemingly endless array of adjustments, the objective here is to get the vehicle running. Build the tune on the laptop that will be used with the vehicle.
At this point, the laptop is not plugged into the ECU. The objective here is to get you comfortable with the software, navigating it, etc. so have fun!
The following 10 steps apply to the V2 software.
1) Launch the Holley EFI software from the icon on your desktop.
2) Choose Open Global Folder.
3) Double-click on the Custom Calibrations (Cals) folder.
4) Double-click on the “496 650HP” (or other applicable engine) Global Folder.
To prevent making changes to this tune, make a copy of this global folder, which is specific to your application, before proceeding. (To do that, click on File > Save Global Folder As and choose your folder name. Type an appropriate name for your tune, and click Save. Save your tune in the Custom Cals folder to make it easy to find later.)
5) From the Toolbox menu, select Preferences.
Check Display Pressure as PSIA if you’d like to see MAP readings in PSI versus kPa. If you are using an HP EFI ECU, you also select that here.
6) Click on the System ICF icon on the taskbar (looks like an ECU). This brings up the SYSTEM PARAMETERS box in the left column.
The SYSTEM PARAMETERS settings allow you to set specifics about the engine, fuel delivery, ignition triggering, how the ECU processes the feedback from the oxygen sensor, etc.
7) Let’s begin with Engine Parameters.
• Change Engine Displacement
• Change Fuel Type
• Change Wideband Oxygen Sensor
• Change Number of Sensors; this brings up a Sensor Averaging window, and for now we select Average
• In the FUEL SYSTEM box, change System Type. As an example, 83LB Holley 522-838 will automatically trigger the low-impedance setting in the Injector Type selection in the INJECTOR SET 1 box.
8) Click on Ignition Parameters in the SYSTEM PARAMETERS box on the left.
• Change Ignition Type to Custom, which brings up the CRANK SENSOR window
• Sensor Type default should be DIGITAL FALLING (in this case that was correct)
• Set TDC Tooth Number (11 in this case)
• Change CAM SENSOR type (set to Not Used for this Olds EFI conversion)
• Change OUTPUT SETUP type (Points Output in this case for the ECU to trigger the MSD Digital 6AL box)
• Click again on Ignition Parameters on the left
• Set CRANKING PARAMETERS timing (we chose 12.0 degrees)
• Set the MAIN OVER-REV REV LIMITER
9) Click on Closed Loop/Learn in the SYSTEM PARAMETERS box on the left. Then:
• Select Enable Closed Loop
• Click on the Learn Parameters box at the top
• Select Base Fuel Learn Enabled (for now, leave the Base Fuel Learn Gain at 100 percent)
• Click Save and close the SYSTEM PARAMETERS box before proceeding
When using a crank sensor, you need to define its type as well as which tooth rests nearest the pickup with the engine at TDC. In addition, you need to provide specifics as to which type of cam sensor you have and how you’d like the ECU to trigger the ignition system.
10) Click on Sensors ICF Icon
We used a 1-bar MAP sensor in this installation, which is the default. All of the other sensors in the software are also set to default to the Holley sensors we used in the installation. It’s never a bad idea to verify this, though.
• Click Save
• Close the SENSORS box before proceeding
TARGET AIR/FUEL RATIO: The values in each of these cells is based on E85. Since we began with a tune that was originally developed on the gas scale, we converted the existing values to E85 values using a Lambda multiplier as shown in the math below. You can achieve smooth transitions from cell to cell by highlighting multiple cells, right clicking, and using the Fill Column Values and Fill Row Values functions.
11) Click on the Fuel ICF Icon.
The FUEL SETTINGS allow you to develop a Target Air/Fuel Ratio Map, which is a function of both engine RPM and MAP. The software also offers advanced settings that can be made to the fuel settings to improve startup, eliminate bogs on throttle transitions, etc. In addition, the software allows you to enrich the mixture based on coolant temperature and/or air temperature as well as during acceleration and deceleration. Finally, you can also fine-tune that rate of change of enrichment with respect to numerous variables.
• Modify the Target Air/Fuel Ratio
Table (from gasoline to our use of E85) as follows:
14.7:1 (1 Lambda) is stoichiometric for gasoline
9.8:1 (1 Lambda) is stoichiometric for E85
1 Lambda = 14.7:1 X A/F ratio/14.7 = Lambda
Lambda x 9.8 = correct E85 value
For example, consider a cell with 13.6:
13.6/14.7 = .925 Lambda
.925 Lambda x 9.8 = 9.06
This measurement represents the conversion of the gas value to value for E85.
Each of the cells in the table has a resolution to one-tenth. Round up to the nearest tenth to make the mixture leaner; round down to make it richer.
Changing the values in the Target Air/Fuel Ratio Table is easy; click and drag all of the cells with the same value, type in the value you desire, and press Enter. All cells are updated accordingly.
All values that were listed at 14.0 were changed in this table to 9.8 to achieve 1 Lambda with E85 in the all-important idle and cruise (drivability) areas, which is what was previously determined works best for the combination in its given climate when it was carbureted.
Remember, we just need to get a base tune in the ECU so we can start the engine. Additional tuning may alter these values. There are many additional FUEL SETTINGS, but for now, we can leave them as is from the tune we’re tweaking.
• Click Save
• Close the FUEL box before proceeding
12) Click on the Idle ICF icon.
• Click on the Idle Speed tab at the top. (Idle speed is pre-set at 1,000 rpm. We tweaked this a bit for when the engine warms up. You can either enter the values in the white boxes at the top and press enter, or click and drag the yellow boxes to the desired values.)
• Click Save
• Close the IDLE box before proceeding
BASE SPARK: You are going to use the data you log for ignition timing for your combination. From that data, you will enter values in the table that coincide with what you ran at idle, cruise, and WOT. You can achieve smooth transitions from cell to cell by highlighting multiple cells, right clicking, and using the Fill Column Values and Fill Row Values functions.
13) Click on the Spark ICF icon.
Pull out the notes that you took earlier regarding the timing your vehicle had before (assuming this isn’t a fresh build).
The SPARK SETTINGS allow you to build a Base Timing Table relative to RPM and MAP, manage retard for an optional knock sensor (electronic spark control, ESC), and set up modifiers for the timing based on coolant temperature and/or air temperature.
• Click on Base Timing Table
• Modify the table according to your combination (in this case we set all cells to 31 degrees, which is exactly how timing was set up before we began the EFI conversion. Later, we add some timing in the idle and drivability areas to improve the burn of the mixture, improve fuel economy, lower exhaust temperatures, etc.)