Ford Truck Flex Fuel Tuning Guide

Introduction

Getting to know the Ford F-150

Here we will go over a few of the basic details and terminologies that are specific to Ford before we begin tuning on a COBB Accessport equipped Ford Ecoboost vehicle.

• 3D Breakpoint Setup– The Ford ECU uses a new style of 2D axes in select 3D tables. In these tables both the X and Y axis have "paired" data. On tables that would require it, we have broken these out for editing in separate folders. The axes are generally index based and may require manipulation to both the index and/or the data to properly display graphs or to utilize greater breakpoint resolution.  Our OTS maps should have good base settings which can be modified further if need be
  
  
  

• Boost Control – The Raptor does not directly target boost in stock form but rather a target engine torque. Engine torque is calculated based on numerous variables such as: pedal position, air flow mass, knock, KOM, and RPM.  The general strategy of the Raptor is to convert and crosscheck mainly torque, load, and airflow, choosing the lowest value, and then clipping the engine output at that value.  Raising wastegate position directly with out modifying other limiters will have little to no impact other than to cause undesirable PID activity and oscillations.   
  
  
  

• Fuel Control – The Raptor operates in a constant closed-loop state, constantly utilizing the A/F values in its tables and making closed loop adjustments via the feedback from the factory wide-band O2 sensors (1 per bank). 
  
  
  

• Ignition Control – The Raptor consists of three primary methods to control spark: MBT, Borderline, and Cylinder Pressure. The ECU also allows full dynamic advance and retard based on octane learning and knock sensor feedback. There are up to 16 primary tables for each method, along with accompanying compensations. The majority of heavy load operation will take place in the borderline timing tables, however this can be clipped by any other timing table from the other categories if they are lower.  Watching the Spark Source and HDFX monitors will give you a good idea of which set of tables are being utilized at any given time.   
  
  
  

• MAP Based – These vehicles use a MAP based airflow system. This is also known as Speed Density.
  
  
  

• Throttle Closures – The primary method of controlling torque on the Raptor is done with the assistance of the drive-by-wire throttle system.  The factory tune allows the throttle to close to less than 20* (of the 82* max) which can result in extremely consistent torque delivery. There are two main offenders that will result in throttle closures: Load and Boost. We recommend adjusting these limits higher to take full control of the throttle. The most common throttle closures will happen at peak torque when TIP Actual is likely surpassing TIP Desired.  Adjusting the Wastegate Position Base table is the best way to help reduce throttle closures.  All throttle closures are not necessarily bad.  If you are hitting your load and torque targets and the transitions are smooth throttle closure can be an ideal means of hitting peak torque quickly while also maintaining a safe torque value.    
  
  
  

• Knock Octane Modifier (KOM) - A learned multiplier for ignition timing where optimal numbers are +1, and -1 will indicate less than optimal settings or fueling.  The value will also impact other strategies like Low Speed Preignition (LSPI).  Those familiar with other EcoBoost Fords will see strong similarites between KOM and OAR - KOM simply acts as an inverted OAR.

Commonly Used Acronyms

Preparing to calibrate the vehicle

Before anything make sure you go over our Pre-Tuning Guide

For information on using our software check out these areas for specific articles

Vehicle Specific Questions

Step 1 – What is the mechanical configuration of the vehicle?

The first step in tuning these vehicles is choosing a COBB Tuning Off-The-Shelf (OTS) calibration that most closely matches the mechanical components and modifications of the vehicle to be tuned.  Refer to our map notes and apply the map that most closely matches your vehicle's mechanical configuration.

Step 2 – What fuel is the vehicle using?

Please note that COBB Tuning offers select performance calibrations for two different fuels: 93 octane (98 RON), 91 octane (95 RON). ACN91 octane from Arizona, California, or Nevada is compatible with our 91 octane calibrations.  All calibrations are made with fuel that contains 10% ethanol.  If you are using 94 octane with 0% ethanol we recommend running the 91 octane calibration.  If your fuel does not meet the standard of the available COBB maps you will need to adjust the calibration accordingly. Take a moment to compare and contrast timing, boost, and ignition tables from each type of calibration. Higher octane fuels support more ignition timing, higher boost levels, and leaner air to fuel mixtures compared to lower octane. Using a map designed for high-octane with low-octane fuels may result in engine damage.

Step 3 – What type of air intake is on the vehicle?

These vehicles utilize manifold absolute pressure (MAP) sensors located pre and post throttle body to measure the mass of air entering the engine. Filter configuration does not necessarily require tuning but heavily contaminated air filters of both OEM and aftermarket construction were found to reduce power output at moderate to high engine speeds. Frequent air filter cleaning and/or replacement is recommended for best performance and engine protection.

Getting Started

Whether you're starting from a stock calibration or a Cobb OTS map, you will want to get a baseline of current engine operation in order to decide your next steps, tuning-wise.  The following list will provide you with information on which tables are active under various pedal position and load conditions.

Good Parameters To Log

• Accel. Pedal Pos. (Translated) – Accelerator pedal position after drive mode & Dynamic Pedal Control translations

• Actual AFR (Average) – Wideband front oxygen sensor readings converted from Lambda to AFR, averaged between Bank1 and Bank2.

• Airflow Limit Source – The currently active load/airflow limiting source; reference the monitor guide to understand the translations this monitor and the tables currently in use.

• Boost Pressure – Manifold pressure (relative). This is MAP minus Barometric pressure.

• Charge Air Temp. – (CAT) Charge air temperature as measured post throttle body.  It is combined with the MAP sensor on the intake manifold.  

• Coolant Temperature – Engine coolant temperature.

• DFI/PFI Split Actual - The proportional split of fuel delivery between the direct fuel injection (DFI) system and the port fuel injection (PFI) system; 0% = all DFI, 100% = all PFI.

• Engine Speed – Engine speed in revolutions per minute (RPM).

• ETC Angle Actual – Electronic throttle control actual angle.

• Fuel Rail Pressure Actual – The fuel pressure as measured in the fuel rail (high pressure system).

• Fuel Source - The currently active fueling mode; reference the monitor guide to understand the translations between this monitor and the tables currently in use.

• HDFX Weight Table 01-15 - The proportional weights of all different HDFX modes; HDFX modes will be referenced by speed density tables, ignition timing tables, and load limiting tables.

• Ignition Timing Corr. Cyl (1-6) – Individual cylinder timing correction in degrees (+/-). 

• Ignition Timing Cyl (1-6) – This is the final actual ignition timing after all correction and adjustments in degrees before TDC.

• Knock Octane Modifier  - This is the global octane learning system that is used on the Raptor; very similar to OAR, but inverse.  +1 indicates maximum timing advance and maximum load limits, -1 indicates minimum timing advance and minimum load limits.

• Load Actual – This is actual calculated engine load value (absolute).

• Load Desired (TQ Control) - This is the current load limit.

• LTFT – Long term fuel trims displayed in percent.

• Power Demand Status - Indicates whether or not the power demand threshold conditions have been met; relates to fueling and load limiting.  0 = not active, 1 = active.

• STFT – Short term fuel trims displayed in percent.

• Spark Source - The currently active spark mode; reference the monitor guide to understand the translations between this monitor and the tables currently in use.

• TIP Actual Absolute - Actual throttle inlet pressure (pre-throttle body), in absolute pressure.

• TIP Desired Absolute - Target throttle inlet pressure (pre-throttle body), in absolute pressure.

• Turbo PID I-Term - The integral component of the PID boost error system.  This is added to the feed-forward wastegate position base table values.

• Wastegate Position – This is the final commanded wastegate position for the wastegate actuators after PID system compensations.

Timing Corrections

Negative timing corrections should remain as minimal as possible, with that said small negative timing corrections are acceptable and can and will take place. When logging all cylinders corrections under full throttle, consistent negative corrections across multiple cylinders or incremental corrections indicate excessive knock and is a sign that the map might be too aggressive for the mechanical condition of your vehicle or the octane used. 

Fuel Trims

Fuel trims refer to adjustments being made by the ECU dynamically to the base fuel table to get the proper air fuel ratio. Short term fuel trim refers to adjustments being made in response to temporary conditions. Long term fuel trims are used to compensate for issues that seem to be present over a longer period. Fuel trims are expressed in percentages; a positive value indicates lean (ECU is adding fuel) and negative values indicate rich (ECU is subtracting fuel). Fuel trims are generally calculated by using a wide set of data values, including pre-cat O2 sensors, intake air temperature/pressure, ECT, knock sensors, engine load, throttle position, and even battery voltage can effect fuel trim. Long term fuel trims generally should not exceed +/- 10%, while short term trims at idle should be in the +/- 5% range. The Raptor ECU has the ability to adjust up to nearly +/- 30%.

HDFX and Cam Phasing

Introduction

Cam phasing may seem like an odd place to start a tuning guide, but cam position is a cornerstone of the Ford EcoBoost control strategy.

The relative positions of the intake and exhaust cams will determine the currently active HDFX mode.  HDFX stands for 'High Degree of Freedom Executive' and is a wide-reaching feature that will select which tables are active for ignition timing, speed density, load limiting, and load translation.  Further detail will be given for each of these affected sub-systems in later sections.  For now, we will focus on how HDFX modes work and how you can monitor this system.  Understanding and becoming comfortable with the HDFX system is elemental to making efficient progress with a Ford EcoBoost vehicle.

There are 16 different HDFX modes - Table 01 through Table 15 and Optimum Power (OP).  Despite the name, the Optimum Power mode is not used in Raptor or in most other supported EcoBoost vehicles.  The translation between exhaust cam and intake cam position is set by the Mapped Points (Exhaust)/(Intake) tables, pictured below.  For example, if the intake cam is at -60* and the exhaust cam at 30*, the engine would be operating in HDFX 15.  These values should not be changed from the factory data.

Logging HDFX

Here is an example datalog of a WOT pull on a 2018 Raptor.  The top graph shows pedal position and RPM.  The lower two graphs show most of the HDFX Table Weights; a few table weight monitors were intentionally omitted from this logging list because previous logs showed that they did not register much more than ~1% weight.  Note at the vertical line that the sum of all HDFX table weights equals 100%.  As you can see later in the RPM range, there can be several HDFX modes currently active with very small percentage weights.  These changes in HDFX mode occur due to changes in intake and exhaust cam position as the engine accelerates through the pull.

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Working with HDFX

If you scan through the tables that are available in Accesstuner Pro, you will notice several families of tables - of identical dimensions and axes - with the suffix of "Table 01" through "Table 15".  For example:

Notice in the table tree (left) how these tables are named and arranged in a group.  Seeing a group of tables like this is an easy way to spot a system that is HDFX-dependent.  In the middle and right photos, we can see example table data; both the Load and RPM axes are configured identically, but the z-data is different.  Consider the following conditions:

1. You are monitoring all of your HDFX Weight Table 'X' monitors and see that the engine is running 100% in HDFX Table 1.  At 5500RPM and 1.800% Load, the commanded Borderline ignition timing value is 1*.

2. You are monitoring all of your HDFX Weight Table 'X' monitors and see that the engine is running 100% in HDFX Table 2.  At 5500RPM and 1.800% Load, the commanded Borderline ignition timing value is 6*.

3. You are monitoring all of your HDFX Weight Table 'X' monitors and see that the engine is running 50% in HDFX Table 1 and 50% in HDFX Table 2.  At 5500RPM and 1.800% Load, the commanded Borderline ignition timing value is 3.5*.

   1. We came to this ignition timing value by applying the weighted averages shown by our HDFX Table monitors. 

   2. Borderline Ign. Timing = (HDFX Table Weight 1)(Borderline Timing Table 1 z-data) + (HDFX Table Weight 2)(Borderline Timing Table 2 z-data)

   3. Borderline Ign. Timing = (0.5)(1*) + (0.5)(6*) = 3.5*

If you want to change an HDFX-dependent system, you can see that it is important to understand which HDFX modes are operational.  If you wanted to reduce ignition timing in condition #3 from above, editing ignition timing in Borderline Timing (Table 7) or (Table 8) for example, would not yield an actual change in ignition timing.  Only changes made to Table 1 and 2 in that RPM/Load range would net a change.

Ignition timing will be discussed in further detail later in the tuning guide, this was just used as an example of how the HDFX system works.

Tuning Cam Position at WOT

Target exhaust and intake cam position while at WOT come from these two tables - VCT Exhaust Desired Angle (Optimum Power) and VCT Exhaust Desired Angle (Optimum Power).  Do not get confused by the 'Optimum Power' label, as this does not mean that optimum power HDFX mode will be used.  As a reminder, optimum power HDFX tables are not active in Raptor.  The ECU will calculate the best fit for different HDFX modes (1-15) as the cams phase through a pull.  Here is the factory data for the 2018 Raptor:

Since any change made to these tables will have so many downstream changes for ignition timing, speed density, load limiting, and load translation, it can be very challenging and time intensive to make changes to WOT VCT-i/-e desired angle, as power gains or losses may actually be attributed to changes in the related HDFX systems.  In our experience developing OTS maps, only slight gains are available from fine-tuning cam phasing.  If you choose to edit these tables, it is best to work through other systems to get in the ballpark of your final power/torque targets, and then circle back to fine tune these and revise downstream changes as necessary.

Pro-Tips

1. Cobb Custom HDFX Monitors: all supported Ford EcoBoost platforms have a LOT of monitors available for you to log, but only a handful can be logged simultaneously.  To help cut down on the number of monitors that you need to log for HDFX, we have created these custom monitors: 

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   2. These monitors sort through all of the HDFX Weights to indicate the highest, 2nd highest, and 3rd highest HDFX Tables at that exact moment.  The Weight tables show the respective % weight of these tables.

2. Baseline Logging HDFX: if you are starting your tune and are NOT changing your target VCT-i/-e angles, you can take a datalog with all of your HDFX Weight Table 'X' monitors selected through a WOT pull.  This shows you exactly which HDFX modes are active, and when they are active.  So long as you do not change your VCT targets, the HDFX curves will not change.  Save the log as an easy reference for the rest of your tuning process, and pull those monitors out of your datalogging list to free up space for other monitors. 

Knock Octane Modifier (KOM)

Introduction

Knock Octane Modifier (KOM) is a global octane learning system, and operates nearly identically to the Octane Adjustment Ratio (OAR) system that has been present in Ford EcoBoost calibrations for years.  Based on input from the knock sensors, KOM can increase or decrease based on inferred fuel quality.  KOM, like OAR, will influence load limits and ignition timing compensations to increase or decrease desired engine output as fuel quality permits.  While KOM maintains the same possible value output range as OAR (-1 to +1), the inferred octane quality has been inverted.  Maximum engine load limits and maximum ignition timing will occur when KOM is +1, whereas OAR would be -1.  Similarly, minimum engine load limits and ignition timing will occur when KOM is -1, whereas OAR would be +1.  Like OAR, KOM is the best way to quickly estimate how happy the engine is with the calibration.  KOM is an available monitor that you can watch/datalog - "Knock Octane Modifier".

We consider it best practice to tune the vehicle at a KOM of +1.  If dyno or road tuning is performed at KOM lower than +1, additional engine load or ignition timing could be added in as the engine learns up during normal driving conditions – this could pose a threat should these increases be significant.

KOM Limits

Two tables exist that can limit maximum KOM without the engine actually encountering knock.  Maximum KOM vs. ECT will limit KOM at cold and very hot ECT – this can limit maximum available power while the engine is still cold and limit power if overheating.  Maximum KOM vs. Engine Speed can limit engine power depending on RPM.  Here is the factory calibration data for these tables on a 2018 Raptor:

For example, an engine that has historically operated knock-free will learn to a KOM of +1; however, if coolant temperature is low, KOM will be limited to a lower value until ECT crosses the threshold configured in this table.  Similarly, if this engine operates in an RPM range where KOM maximum is lower than the learned KOM value, KOM will be decreased to the maximum value configured in this table.  If inadequate time is spent allowing the engine to warm up for a dyno pull, engine power can be significantly limited.  OTS maps allow +1 KOM at all engine speeds and decreases the ECT threshold for maximum KOM.

Default KOM

Anytime that the ECU is reflashed, the ECU will also be reset.  You may be familiar with the sort of changes an ECU reset can have on other vehicles, like erasing learned long term fuel trims.  On the Raptor, an ECU reset will also revert KOM back to its default value.  This value is configurable in the table Default KOM (Init/FMEM).  Two things to consider:

1. What was KOM at when the Raptor came in for a tune?  This can help indicate whether or not the inferred fuel quality is low or high, and can give you an idea of what sort of ignition timing changes may be necessary.

2. If the truck is happy at a KOM of +1, you will want to set the default KOM to +1 during the tuning process.  This way, you do not have to wait for the ECU to learn KOM up to +1 after every flash.

KOM Load Limiting

Current OTS calibrations for Raptor have been designed to use the Low Speed Preigniton tables as the primary maximum load limit.  Three tables - LSPI Load Limit (High), LSPI Load Limit (Mid), and LSPI Load Limit (Low) - will interact with KOM.  Each table has axis of Charge Air Temperature and RPM, and can be used to limit the maximum engine load permitted.  These tables will be familiar if you have tuned other EcoBoost Fords that utilize the OAR strategy.  Here is the factory data for a 2018 Raptor:

KOM interacts with these tables to adjust maximum engine load permitted based on inferred fuel quality.  If KOM = +1, load limits will be pulled from the LSPI Load Limit (High) table.  If KOM = 0, load limits will be pulled from the LSPI Load Limit (Mid) table.  If KOM = -1, load limits will be pulled from the LSPI Load Limit (Low) table.  KOM values between these three points will interpolate load limits between the respective tables.  Relying on these tables can represent a significant engine safety benefit, in that a decrease in KOM will not only globally decrease ignition timing across all cylinders, but also decrease the maximum engine load.  If you are tuning for a specific fuel octane, and tune at a KOM of +1, you can copy and paste your LSPI Load Limit (High) table data into (Mid) and (Low) tables, and then decrease each by a percentage you deem appropriate.  For example, you could apply a 10% decrease in (Mid) tables and 20% decrease in (Low) tables, relative to (High).  Should you choose to use an alternative tuning strategy for optimal-conditions load limiting and do not use LSPI Load Limit (High), you can still configure your (Mid) and/or (Low) tables to decrease maximum engine load and promote engine safety in your calibration.  The monitor Airflow Limit Source will return a value of 5 while LSPI load limits are active.  Further detail on load and boost control will be found later in the tuning guide.

Borderline Timing Compensation

In the Borderline Timing tables, you will find the table BL Timing Comp. (KOM), pictured below.  The values found in this table will be multiplied by the current KOM value and added to the current Borderline Timing commanded.  Table values will be positive, so that when KOM is +1, ignition timing will be advanced.  When KOM is -1, ignition timing will be retarded by an equal but opposite amount.  This timing compensation will only be applied to actual ignition timing when Borderline Timing is active (when Spark Source = 2).   Keeping these values large will allow for a greater swing of total ignition timing depending on KOM, lending itself to greater engine safety.  Factory tables are configured to allow for a swing between 91 octane and 84 octane; if tuning for a single octane and expecting the customer to only fill with that fuel, values in this table can be made smaller without concern for nerfing this feature.  Further detail on ignition control will be found later in the tuning guide.

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Fueling Control

Introduction

The Raptor fueling system operates with full-time closed-loop control, and has one wideband oxygen sensor per cylinder bank.  Fuel delivery is split between direct and port injection; the dynamics of that split will be described in greater detail in this section.  There appears to be a healthy amount of headroom in total fueling capacity on a stock turbo truck with conventional pump-gas.  To run E85 fuel, upgrading the port injectors and in-tank fuel pump may be necessary.   

Understanding Fuel Source

Whenever you are tuning the fueling system, it is helpful to datalog the monitor 'Fuel Source'.  This monitor outputs a number which correlates to the specific fueling mode that is in current use.  Reference the Ford Data Monitor Support document to understand the translations for the 'Fuel Source' values:

Engine & Transmission Monitor List for Ford Vehicles

When tuning WOT fueling, you will become most familiar with a fuel source of 5 - Power Demand Fueling.

Power Demand

The Ford EcoBoost control strategy uses a feature called 'Power Demand' to regulate fueling, cam control, and load limiting.  Power Demand is a binary threshold determined by pedal position, and has its drawbacks because of that binary behavior.  Careful attention should be paid to the threshold in order to both maintain emissions quality under normal driving conditions as well as fuel economy.  Here is the factory data for Power Demand Threshold on a 2018 Raptor:

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We have introduced custom code into the power demand threshold system to use APP (Translated) instead of APP.  This change was made due to the Dynamic Pedal Control (DPC) feature, where customers can change throttle translation to be more or less sensitive directly from the Accessport.  Once APP (Translated) eclipses the value found in this table, power enrichment can begin.  Several tables exist to control the transition from stoichiometric operation (Fuel Source = 0) into power demand (Fuel Source = 5), managing delay time and the blending rate of lambda changes.  Explore the 'Power Demand' folder in Accesstuner Pro to view the available tables. 

It is helpful to consider the power demand threshold as the threshold at which power enrichment is necessary due to component protection.  If you are drastically increasing the power output of the engine, re-configuring the Power Demand Threshold to a lower APP value will likely be necessary.  We'll use some easy numbers to explore this idea; some concepts have not yet been covered by this point in the tuning guide, but we'll keep it as conceptual as possible.  Reading through the boost control section will offer improved understanding of the following.

• Let's assume that in a stock map, the Throttle Requested Torque table linearly increases from 0 ft./lbs. at 0% APP to 500 ft./lbs. at 100% APP.

• With a stock PD Threshold of 90%, the factory has told us that the engine can safely operate at a stoichiometric lambda until 90% of 500 ft./lbs., or 450 ft./lbs.; above this threshold, power enrichment is needed to safely meet power demands.

• Now let's assume that in a performance calibration, the Throttle Requested Torque table linearly increases from  0 ft./lbs. at 0% APP to 600 ft./lbs. at 100% APP.

• With a stock PD Threshold of 90% on this performance calibration, stoichiometric operation would be active until 90% of 600 ft./lbs., or 540 ft./lbs.

• If you change the PD Threshold on this performance calibration to 75%, stoichiometric operation would be active until 75% of 600 ft./lbs., or 450 ft./lbs. - bringing you back to the output level where the factory has indicated that power enrichment is necessary for component protection.

This example is not perfect because it ignores Partial Throttle load limiting - load limits that are active when Power Demand is not active.  Further detail on this will be covered in the Boost Control section.  You are also able to configure the RPM axis to whatever RPM values that you see fit, should you want to have a different power demand threshold across the rev-range.

Dialing in the Ideal Lambda

Tuning the Power Demand fuel target is fairly straightforward, and is handled by a single table - Desired Lambda (Power Demand), shown below from a stock 2018 Raptor:

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Notice that the axes of RPM and ECT are completely independent of load, which could be seen as a shortcoming of the factory logic.  If you prefer tuning in Lambda, you can switch to metric units under 'Configure Options' → 'Display'.  When logging, you view the measured AFR of the engine with Actual AFR B1 and Actual AFR B2, or the custom monitor Actual AFR (Avg).  When considering what kind of AFR you want to run, consider the proportional fuel delivery between the DFI and PFI systems at WOT (more detail below).  Conventional wisdom suggests that you can run a leaner AFR at full load on a DI engine than a PI engine; but when over 50% of your fueling is being delivered from the PI system, you need to re-think what a safe target AFR will be.  The factory tune runs very rich right at redline, and somewhat lean at lower RPM.  We have found that a nice taper from mid-to-high 11's to 11.0 by redline works very well.

It is important to note that changing Desired Lambda can have a significant effect on ignition timing.  Further detail on the ignition system will be covered later, but consider the following table - BL Timing Comp. (Open Loop):

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The name may be confusing - the engine is not operating in open loop when this table is active.  However, when Borderline ignition timing tables are being used, the timing compensation found in this table will be active.  You can see in this table how significant some of the changes can be.  For example, lowering target AFR from 12.64 at 3000RPM to 11.02 would represent a 3.24* increase in ignition timing advance.  

Direct and Port Fuel Injection

The EcoBoost Raptor uses both direct fuel injection and port fuel injection – with one of each injector type per cylinder.  The ECU can adjust the proportion of desired fuel mass injected between the direct injectors and the port injectors.  At idle, 100% of the fuel mass injected comes from the port injectors.  At light load cruise, nearly all of the fuel mass injected comes from the direct injectors.  At WOT, the factory calibration approaches a near even split between the two, but slightly favors direct injection.  This system has two advantages for performance calibrators and enthusiasts – cleaning of carbon build-up on intake components that can occur on DI-only engines, and a cost-effective means of increasing the total fueling capacity.  The stock fueling system appears to be capable of handling low-to-mid levels of ethanol concentration, but further investigation will be needed to estimate the maximum ethanol percentage that can be reliably run.  

• Direct Injection System:

   Those familiar with direct injection tuning tables for other EcoBoost Ford applications will recognize the tables available for Raptor.  HPFP controls also carry over from other EcoBoost Ford applications.

• Port Injection System:

   Conventional injector characterization tables are available.  Different table names are used in ATP versus some other tuning solutions, so we’ve provided a list below to translate the table names found in FIC’s Ford Injector Characterization table to their equivalents in ATP. 

  • Format:
    (FIC Table/Value Name) = (ATP Table Name)
    1. Ahisl = Fuel Injector Slope (High)
    2. Alosl = Fuel Injector Slope (Low)
    3. Fuel_bkpt = Fuel Injector Slope High/Low Breakpoint
    4. Minpw = Minimum Injector Pulsewidth
    5. FNPW_offset = Fuel Injector Latency
    6. Inj. Offset Modif vs. Rail Temp = *WORK IN PROGRESS*
    7. FNPW LSCOMP = Fuel Injector Slope Pressure Compensation (Low)
    8. FNPW HSCOMP = Fuel Injector Slope Pressure Compensation (High)
    9. FNPW BKCOMP = Fuel Injector Slope High/Low Breakpoint Compensation
    10. FNPW OFFCOMP = Fuel Injector Latency Compensation
    11. Inj. Slope Modif vs. Rail Temp = *WORK IN PROGRESS*

• Commanded DFI/PFI Split: As load and airflow increases when tuned, careful attention must be paid to the fueling proportion delivered by the direct injectors – too much, and fuel rail pressure can drop significantly.   You can compare Fuel Rail Pressure Error to see how significant the difference is between target and actual.  To avoid this, you can increase the proportion of fuel mass delivered through the port injectors.  Consider your DFI/PFI split when deciding on your desired AFR for power demand – when over half of your fueling is coming from port injectors, you may not be able to run as lean a target AFR as you might on a pure DI engine.  There are three tables that you will need to be aware of when making changes to desired DFI/PFI split: (1) DFI/PFI Commanded Split (Warm), (2) DFI/PFI Commanded Split Maximum (Warm), (3) DFI/PFI Commanded Split Minimum (Warm); each have axis of load and RPM.  As you make changes to the commanded split, double check your minimum and maximum tables to avoid running into these upper and lower limits.  A value of 0% indicates full DFI fueling, and 100% indicates full PFI fueling.  We recommend only editing the highest load range of this table to maintain emissions quality in idle and cruise operation.
  
  
  
  

Ignition Control

Introduction

As with all EcoBoost engines, ignition timing is both extremely dynamic and a major contributor to power productions.  Run-to-run variances of just 1* of ignition timing on the Raptor can be worth up to 10-15WHP.  Understanding how the system works, what compensations are active, and how to compare run-to-run data is key to making consistent power.  More importantly, it is a key aspect of understanding how your calibration changes are actually influencing power production.  If you increase boost, but the charge air temperature compensation has decreased ignition timing significantly, you may see a decrease in power.

The ECU compares the output data of each different spark source and selects the lowest at that HDFX/Load Actual/Engine Speed.  The monitor 'Spark Source' will indicate which family of ignition tables will be in use.

Consider this example, showing stock calibration data from a 2018 Raptor:

Let's assume that the engine has an HDFX Weight Table 01 value of 100%, Load Actual is 2.200%, and Engine Speed is 3000 RPM.  The Borderline table would output an ignition advance of 0*, while the MBT table would output an igniton advance of 12.9*.  The ECU will compare these, select the lowest (Borderline), and the base ignition timing before compensations would be 0*.  Spark Source, covered below, would be 2 to indicate that active ignition timing is being pulled from the Borderline table.

Understanding Spark Source

Whenever you're tuning the ignition system, it is helpful to datalog the monitor 'Spark Source'.  This monitor outputs a number which correlates to the specific ignition mode that is currently in use.  Reference the Ford Data Monitor Support document to understand the translations for the 'Spark Source' values:

Engine & Transmission Monitor List for Ford Vehicles

When tuning WOT ignition, you will become most familiar with a spark source of 2 - Borderline.  You may also encounter spark source 5 (Cylinder Pressure) when running an upgraded intercooler or when using high ethanol content fuels.

Spark Source MBT

This set of timing tables represent the minimum timing for best torque of the engine based upon extensive modeling and testing on an engine dyno.  These values are achieved on high octane fuel and should not be used as a reference to adjust timing on standard pump gas.  During low load conditions these tables will be used to optimize combustion and fuel efficiency.  Typically, you will not need to modify these tables.  You can tell that these spark tables are in active use when Spark Source = 1.

Outside of the the HDFX MBT ignition tables, there are two MBT-specific compensations: MBT Timing Comp. (ECT) and MBT Timing Comp. (Lambda).  These compensations will be added to the base MBT table values.

Spark Source Borderline

This set of timing tables represent the maximum timing to remain on the border of the knock threshold. These values are the result of extensive modeling and testing on an engine dyno using standard pump 91 octane fuel (95 RON).  These tables will most commonly be in use while the engine is under medium to high load, and are the tables that you will need to pay most attention to while tuning WOT ignition.  You can tell that these spark tables are in active use when Spark Source = 2.

Like MBT Timing, Borderline Timing is also HDFX-dependent.  In order to tune these tables, you will need to know 1) your HDFX Weights, 2) Load Actual, and 3) Engine Speed.  The base output of your borderline tables can be monitored using 'Ignition Timing (Borderline)'.  This monitor displays Borderline timing before all compensations.

Also like MBT, Borderline Timing also has specific compensations: BL Timing Comp. (KOM) and BL Timing Comp. (Open Loop).  These tables are only in use while Spark Source = 2 (Borderline).  

• BL Timing Comp. (KOM) is a timing compensation that is multiplied by the current KOM value and added to 'Ignition Timing (Borderline)'.  Consider this example, using the table screenshot above: if load is 1.0%, RPM is 1000, and KOM is +1, then the BL Timing Comp. (KOM) would be 4*.  If load is 1.0%, RPM is 1000, and KOM is -0.5, then the BL Timing Comp. (KOM) would be -2*.  This table is one of the primary reasons why it is important to create your calibration with a KOM of +1; if you tune at a value lower than this, you are not getting maximum ignition timing advance from this specific table.  Should you tune the car to its knock threshold at a lower KOM value, and the car learns up during normal operation, you could get dangerously high ignition timing.  You can monitor the net output of this table with the monitor 'Ignition Timing Comp. (OAR)'.

  • Pro-tip #1: if you're trying to make a quick ignition timing change, this is an easy table to use.  If you like the change that you've made, you can apply that change to the appropriate Borderline HDFX table afterwards.

  • Pro-tip #2: this table is your key to having octane adaptation within your tune.  The higher the value found in the table, the larger of a change in ignition timing will be should KOM drop.  Keep this in mind when considering engine safety in your tunes.

• BL Timing Comp. (Open Loop) is a timing compensation that is added to 'Ignition Timing (Borderline)' based on the current measured AFR.  This can be a tricky table to work with - anytime that you change target AFR, you will change ignition timing because of this table.  You may want to configure the table to have identical timing values within a small range of AFRs that you want to try; that way, ignition timing is as constant as possible while dialing in AFR.  You can monitor the net output of this table with the monitor 'Ignition Timing Comp. (Lambda)'.
  
  
  
  

Spark Source Cylinder Pressure

The table Cylinder Pressure Timing Limit (Ceiling) is used to limit cylinder pressure inside the engine. These values are the result of extensive modeling and testing on an engine dyno using standard pump 91 octane fuel (95 RON). Often times, these values are conservative and can be adjusted in both low and high load conditions.  This is a single table that is not HDFX-dependent.  If the engine operates in a load/RPM range in which other spark sources create an ignition timing higher than that found in this table, the values found here will be used and Spark Source will be set to 5.

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This spark source has a variety of compensations that are applied to it.  In general, fine tuning of these compensations is not strictly necessary.  You can instead increase the timing ceiling values in the table shown above to clear this limit out of the way of your intended ignition timing.  Be careful when making large changes - if you are tuning the truck to operate in Borderline on a hot day where CAT/ECT are high, the engine could run significantly higher ignition timing than what you intended.  Tuning this table to be a close ceiling to your intended actual ignition timing is a useful tool to protect the engine against unintended or unforeseen increases in ignition timing.

Compensations

We've addressed ignition timing compensations that apply to specific spark sources, but now we'll turn our focus to timing compensations that apply universally to all spark sources.

• Cylinder Compensations:

  these tables allow you to configure individual cylinder timing compensations based on RPM and load.  The factory applies a negative compensation on cylinders 1 and 6, perhaps due to cylinder head cooling characteristics.  You can use your individual cylinder knock counts and ignition timing correction values to determine the appropriate configuration of these compensations.  The individual cylinder tables only have an axis of RPM; but the Timing Comp. Mult. (All Cylinders) has axis of both RPM and load.  Consider this example, using stock cal. data from an '18 Raptor:
  
  
  

At 4000RPM and 1.0% load, the Cylinder 1 timing compensation = (1*)(-2) = -2*; at 4000RPM and 0.4% load, the Cylinder 1 timing compensation = (1*)(0) = 0*.

• Temperature Compensations:

  these tables are some of the most important and most variable timing compensations present in this control strategy.  Fine tuning these tables is essential to creating a calibration that is safe across a wide range of environmental conditions, while not unnecessarily sacrificing power.  You will be able to log the net output of both tables with the monitor Ignition Timing Comp. (CAT/ECT).  This monitor is a great tool to account for pull-to-pull power differences.

• Charge Air Temperature:

  in order to tune the CAT compensation tables, you will need to datalog Charge Air Temperature, Load Actual, Engine Speed, and individual cylinder ignition timing corrections and/or knock counts.  If you see that knock events occur more regularly at higher CATs, you can increase the negative compensation applied at that temperature, load, and/or RPM.  
  
  
  

Similar to the individual cylinder compensations, you have a base compensation table and a multiplier table.  Consider CAT of 150.8*F at 6000RPM and 1.8% load; CAT timing comp. = (-50*)(0.15) = -7.5*.  At a CAT of 69.8*F, 6000RPM, and 1.8% load, CAT timing comp. = (15*)(0.15) = +2.25*.  So, over 80*F of charge air temperature change, you have an ignition timing change of 9.75*!  This will result in a big power difference - something that you will want to be aware of when making changes on the dyno.

Pro-Tip: if you find that CATs are regularly very high during your dyno session, and you don't have the opportunity to test in colder weather, it is advisable that you soften up the positive timing compensations found at lower temperatures.  Not only will this avoid unforeseen knock issues at colder temperatures, but it will also help to limit torque to where you see fit; if you're making 600 ft./lbs. at the wheels in 100* weather, a few more degrees of ignition timing at colder temperatures could increase that significantly.  2* of timing increase can easily represent +20-30 ft./lbs. WTQ.

• Coolant Temperature: 

  this timing comp. and multiplier work exactly the same as CAT comps.  You can expect coolant temperature to sit between 195-210*F under normal, light load driving conditions.  Coolant temperature can increase 15-25*F during a 6th gear pull, possibly more if the fan setup on your dyno is lacking.  The coolant temp. gauge on the dash will get very close to the middle of its range by the time coolant temperature reaches 160*F; I haven't seen it budge much farther than the middle, even with CLT up at 235-240*F.
  
  
  

Pro-Tip: make sure that you perform your baselines and tuned runs when the engine is fully up to temperature.  If you start your first pull when coolant temperature is around 170*F, you could get a few extra degrees of timing compared to later runs.  Increasing the multiplier at high load and high RPM can be helpful to avoid knock during long, multi-gear pulls.  You could rely on CAT comps to handle this, but with an aftermarket intercooler and very high speeds, CAT can become a worse predictor than ECT of the necessary timing decrease during a long session of hard driving.

Ignition Timing Corrections, Knock Response, and Knock Intensity

In addition to the other timing compensations that we've covered, we also have individual cylinder ignition timing compensations that increase and decrease based on knock activity.  Careful attention must be paid to these monitors in order to ensure the safety of your tune.

Useful Monitors:

• Knock Count Cyl1-6: if a knock event is detected by the knock sensors in a specific cylinder, the knock count monitor for that cylinder will increment by 1.  A value of 0 indicates that no knock has occurred in that cylinder.

• Knock Count Total: this a monitor that shows the cumulative number of knock counts across all cylinders.

• Ignition Timing Corr. Cyl1-6: this shows the actual ignition timing correction being applied to each individual cylinder.

• Ignition Timing Corr. (Lowest): this is a custom monitor that compares all of the individual cylinder corrections and displays the lowest value.  This helps to cut down on the number of monitors logged while still reporting "worst case" conditions.

• Knock Intensity Cyl1-6: based on feedback from the knock sensors, intensity of a knock event can be monitored.  Sensor feedback is considered a knock event when intensity eclipses 0.

• Knock Intensity (Highest): this is a custom monitor that compares all of the individual cylinder knock intensity measurements and reports the highest value.  This helps to cut down on the number of monitors logged while still reporting "worst case" conditions.

Ignition timing corrections be positive and negative.  As the engine operates knock free, the correction will increment upwards at a configurable rate and step size.  As knock is detected, the correction will decrease at a configurable step size based on the intensity of the knock event.  However, just because ignition timing corrections are positive doesn't mean that knock is not occurring.  Consider this example, from a modified OTS map on a 2019 Raptor:

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In the upper graph, we can see APP and RPM for context.  In the lower graph, we can see Ignition Timing Corr. (Lowest) and Knock Count Total.  At the beginning of the pull, Ign. Timing Corr. (Lowest) starts at 0 and then begins increasing while no knock activity is measured.  At approximately 5200RPM, we can see that Knock Count Total increments from 0 to 1.  Before the knock event, Ign. Timing Corr. (Lowest) was at approximately 1.37*, and after the knock event is at 0.37*.  So, we have a knock event that still results in a positive timing correction.  Knock events are dangerous regardless of what your timing corrections are, so do not allow yourself to think that "timing corrections are positive, so it's running fine..."

Compare the above graph to this pull on the factory calibration:

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Consider the shape and amplitude of the Ign. Timing Corr. curve.  We can see that at the beginning of the pull, timing is increased in large steps that have long delays between them.  In addition, at the location of the vertical line, we can see that the timing correction has reached 3* of additional advance, but has taken nearly half of the pull to do so.  This strategy that the factory pursues - slow, large jumps in timing with a high ceiling for advance - has its drawbacks when creating a performance calibration.  First, large sudden increases in ignition timing can create a jagged ignition timing curve that, when tuning on the edge of knock, can easily push timing suddenly too far advanced.  Second, the long delay time between increments means that it will take a significant amount of time to add in all of this additional timing.  Last, needing to wait for this timing to be added in may not be a big issue on a long 6th gear pull, but will simply not have the time to reach the safe amount of timing that the truck can run while in lower gears; if it takes 4 seconds for the ECU to add in the 3* of ignition timing advance you want, and a 1st gear pull from stop to redline takes 3 seconds, then you are not able to reach the final ignition timing that you want.  This is just leaving power on the table.

Advance: When configuring the knock-free operating characteristics of ignition timing corrections, you will want to look at these tables:

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• This table sets the upper limit of how positive ignition timing corrections can be at a given load and RPM.  Notice how much room for positive correction the factory calibration will allow: +6* for a majority of the rev range at high load!  Rather than wait for the ECU to gradually increase ignition timing corrections to the upper limit, you can work in this timing advance into your base ignition timing tables for instant power.  OTS maps will typically limit maximum positive corrections to 1-2*.
  
  
  
  

• These tables control the step size of increases made to ignition timing corrections.  Fast vs. normal tables are used depending on knock activity - if a knock count has been registered, the Normal table will be used; if no knock has been registered, the Fast table will be used.  The changeover between these tables is determined by the knock count defined in the table Advance Rate Change (Max).  Configuring these tables to increment in smaller steps can give greater resolution to your correction curve.  Smooth changes will yield an ignition timing curve that will be easier to tune to the knock limitations of the engine.