Introduction

EcuTek ProECU proudly supports the Nissan 5.6ltr V6 engine called VK56-VD found in the following Nissan and Infiniti vehicles:

2010–present Nissan Patrol (and Nismo Variants)
2011–2024 Infiniti QX80
2011–2013 Infiniti M56
2014–2019 Infiniti Q70
2017–2021 Nissan NV2500, 3500 HD and Passenger
2017–2024 Nissan Titan
2017–present Nissan Armada

This naturally aspirated V8 engine has a compression ratio around 10.8:1 or 11.5:1 and produces from 375bhp and 387 lbs·ft (525 Nm) to 428bhp and 417 lbs·ft (565 Nm) depending on the exact model and market.  The Vk56 also includes Variable Timing Control (VTC) on both Intake and Exhaust valves, Intake Variable Valve Event and Lift (VVEL). The VTC is Intake Cam Shaft Opening Angle and the VVEL controls the Valve Duration amount.  Aftermarket supercharged and turbocharged conversions will offer 450+bhp with around 0.5bar boost.

The VK56-VD is Nissans mid generation 5.6L v8 derived from the VK56-DE with updated components such as Dual VTCs, intake VVEL and Direct Injection. More information on the engine and the model coverage of the VD engine is available on Wiki Nissan VK engine.

ECU architecture most closely resembles 370Z with added strategies similar to the VR30 engine control for Direct Injectors and Exhaust VTC angles. The RaceROM features currently available for the Nissan VK56 suite are shown here, and are listed below. VK56VD ProECU RaceROM Supplement

• RaceROM Custom Ignition Timing

• Map Switching

• Launch Control

• Flat Foot Shifting

• Per-gear Rev Limits

• RaceROM Gauge Hijack

• Speed Density

• Knock Warning

• RaceROM Custom Maps

• RaceROM Controller

• Valet Mode

• Custom Parameter Data Logging

!!! CAUTION !!!

EcuTek ProECU tuning tools should only be used by experienced tuners who understand the product and engine calibration.

If you do not fully understand this product then you WILL damage your engine, the ECU or your vehicle.

Please ensure you fully read all EcuTek manuals BEFORE attempting to use ProECU with your laptop or your vehicle.

Use with extreme caution and understanding at all times, if in doubt then do not proceed.

EcuTek accepts no responsibility for any damage to the engine, ECU or any part of the vehicle that results directly or indirectly from using the product.

** If you are in any doubt that you do NOT have the experienced required to use this product then you should NOT USE IT **

Programming

For information on how to program as well as flash recovery, check out.

• ECU Programming Overview

• How to Recover an ECU
  
  

For more software guides check out:

• Software Help and How-To

Tuning Guide

Accelerator and Throttle

Map List

Open

The factory throttle maps are concave as shown in the factory calibration below.  By making these maps more linear the engine will deliver more power and torque for a given Accel pedal position. See where the modified map has been interpolated between 10% and 76% to produce a much more linear shaped curve, so for a given Accel pedal position the ECU will open the butterfly further. Note that this is only altering the Accel pedal output and doesn’t physically create any more power or torque!

Open

The VK56-VD control strategy has a complex relationship between accel pedal and throttle butterfly opening angle that includes cylinder fill and torque calculations.  While exact operation details aren't important, one important thing to note is that the throttle may not fully open below 2400 RPM, this behavior is controlled by the Torque Filtering maps.  Adjusting the two maps shown below in a similar manner will cause the throttle to be fully open at low RPM. This is a very important change for Turbo and Supercharged Forced Induction models.

The Torque Actual map values can be raised in order to influence the Auto gearbox control (AT models). Raising the values on higher load will provide faster harder shifting though high power models may still hit the rev limiter in D mode.

The Torque Demand map (and its corresponding Trustful check map requiring the same values) can also be used to influence gearbox control on forced induction models. Increasing the map values (Nm) will tighten gearshifts and enable faster gear shifting in manual mode. 

Raising the values on high load may help the gearbox change gear before hitting the rev limiter but ultimately this projection of gear shift in Auto mode is out of the ECMs control. There is no need to change this maps on manual gearbox models (MT) and changing them may have undesirable effects on throttle control and VVEL operation. The other table to influence the shift characteristics is the torque demand multiplier map which multiples the values of torque demand the gearbox sees and effect the shift firmness significantly. this map is a gear ratio and RPM based torque demand multiplier limited to 1.25

There are two stages to the accelerator and throttle control. Firstly the physical accelerator pedal position is mapped to a logical position. This allows the manufacturer to offer different drive modes with varying throttle response. Secondly the logical accelerator position is mapped to a target throttle angle.

The relationship between the physical Accel pedal position and the Logical Accel pedal position is controlled by several sets of 2d maps. For vehicles that support the Infinity "Drive Mode" switch, there are four sets of maps: Normal, Eco, Sport and Snow. These maps are also present on some Nissan vehicles without the Drive Mode switch fitted. In this case we suggest that all values are set the same as per the factory settings.

Each drive mode has a slow map and a fast map. These are for different vehicle speeds. It allows the vehicle to be very responsive when driving at high speed, but less responsive for low speed maneuvers like parking. The transition between the slow and fast maps is controlled by the "Accel Map Slow/Fast Switch" map.

Each of the Accel pedal maps has a corresponding Trustful check map, these must be set the same or a DTC fail safe condition will occur.

There are two Accel position to Throttle Angle maps. One is for low speed, the other for high speed. The transition between low and high speed is governed by the "Accel to Throttle Lo/Hi Switch" map. Typically the two maps are set the same and the switch map is calibrated so that only one of the Accel to Throttle maps is used.

When the car is in reverse, there is a reverse gear multiplier map which applies a correction so that the vehicle response in reverse gear can be made to feel the same as in 1st gear.

Camshaft Timing

The engine is fitted with a complex variable valve timing system that allows the ECU to control both inlet and exhaust cam timing (VTC) plus the duration/lift of the inlet valves (VVEL). This makes it very similar to the 370Z except with the addition of exhaust cam target maps.

VTC (Variable Timing Control)

The first system, known as VTC, adjusts the valve timing. It rotates the camshaft relative to the sprocket. The lift and duration of the valve is unaffected. The diagram below shows valve lift against crank angle to illustrate how VTC works. If the VTC system was turned off, the valve would be fully open (centre line) at the VTC reference angle of 118°Crank.

In this diagram the tuner has requested 18 degrees of VTC Advance. So the centre line has moved 18 degrees to the left and is now at 100°Crank. The inlet valves open 18 degrees earlier and they close 18 degrees earlier.

VVEL (Variable Valve Event and Lift)

The second system, known as VVEL, adjusts the valve duration by moving the pivot point of the rocker arm. Valve duration is often measured from valve open to shut in °Crank. But Nissan do not use this convention. Nissan measure the duration from the point at which the valve opens, to the point of maximum lift (centre line). The units are in °Cam. In the diagram below, the VVEL Duration is 55°Cam which would commonly be regarded as 220°Crank. The °Crank measurement is four times the Nissan measurement.

There is a fixed relationship between the valve duration and lift. As duration increases so does the valve lift. The diagram below shows valve lift in mm against crank angle for various durations. Requesting a VVEL duration of 25°Cam will result in a valve lift of about 0.75mm. At the other end of the scale, a VVEL duration of 70°Cam will give a valve lift of about 11.50mm.

VTC and VVEL activity

You can see the ECM controlling the VTC and VVEL after this hot restart, the VVEL angle is reduced as the VTC angle is advanced in this example shown below. Notice how the FTST quickly compensates for the change in airflow.

Tuning the Cam Timing

Tuning the VTC and VVEL systems, at a basic level, is fairly straightforward. The main thing is to adjust the appropriate target maps and the ECU will follow them while remaining within the safety limits that are present to avoid interference.

The VTC Valve Advance maps contain the target advance in °Crank. There is a 3D map for normal driving. Separate 2D maps are used for Wide Open Throttle and Overrun conditions.

The VVEL Value Duration maps contain the target duration in °Cam from the point at which the valve opens to the point of maximum lift (centre line). As before, there is a 3D map for normal driving and separate 2D maps for Wide Open Throttle and Overrun.

The valve duration is physically controlled by a stepper motor that rotates a shaft under the control of the VVEL control module. Having chosen a target duration, the ECU determines the desired Control Shaft Angle and sends this to the VVEL control module.

The ECU uses the "VVEL Control Shaft Angle to Duration" map to determine the Control Shaft Angle. This is a bi-directional map. When the ECU needs to determine the desired control shaft angle from the target duration, it reads the map from right to left. When the ECU needs to determine the actual current duration from the measured control shaft angle, it reads the map from left to right.

You should only need to recalibrate this map if you physically adjust the VVEL hardware.

VVEL Min and Max Limits

The VVEL system has a number of maps that limit the position of the control shaft, and therefore the valve duration (see above). The two maps shown below limit the VVEL control shaft angle by RPM. At 2400 RPM, the minimum CS Angle is 2.88° and the maximum is 47.8°. This allows a target duration somewhere between approximately 28.5°CAM and 61.9°CAM. The stock calibration runs close to these limits so you will probably need to adjust them in order to tune the VVEL system.

Interference Limits

When adjusting the cam timing, it is important to avoid using long valve duration and large cam advance at the same time. Doing so may result in engine damage due to the inlet valves interfering with the exhaust valves or the piston.

There are two safety limit maps to prevent this from happening. The maps have been included in ProECU for reference purposes only. We strongly recommend that you do not adjust them.

When the ECU is selecting the VTC target, it looks at the current VVEL Control Shaft Angle and uses the "VTC Max Advance by VVEL CS Angle" map to determine the maximum allowed VTC target. Conversely, when the ECU is calculating the VVEL Control Shaft Angle, it looks at the current VTC advance and uses the "VVEL Control Shaft Max by VTC Angle" map to determine the maximum allowed control shaft angle.

Starting and Warm Up Cycle

During starting, the ECU will use the "Start-up" Map. Once the engine has started, it will switch to the "First Idle" map for approximately 40 seconds before switching to the "Cold" map. Once the coolant temperature has reached 70°C, the ECU will begin using the "Main", "WOT" and "Overrun" maps as described above.

EcuTek Custom Live Data Parameters

As part of our RaceROM features, we have provided some custom logging parameters to help our tuners achieve optimum control of the VTC and VVEL systems.

The custom parameters, "Inlet Valve Duration", "Inlet Valve Open", "Inlet Valve Shut" and "Inlet Valve Centre Line", all use the familiars units of °Crank. The picture below shows the parameters changing under deceleration from about 3000rpm.

The left window shows the valve has an advance of 30°. The Centre Line is therefore at 118°30°=88°. The duration is 149°. Half of the duration is 74.5°. The Open Angle is therefore 88°-74.5 = 14° and the Shut Angle is 88+74.5 = 163°.

The right window shows that the VTC advance has increased to 33°, but the duration has dropped to 143°. The Centre Line and Shut Angle have advanced accordingly, but the Open Angle remains at 14°. The tuner has presumably calibrated the maps to keep the Open Angle constant.

Next are the maps controlling the VTC and VVEL at the time of the log. When looking at the VVEL map, remember that the VVEL Duration in the maps is in °Cam from valve open to full lift, which is one quarter of actual full duration in °Crank. Therefore 37°Cam means 148°Crank and 35°Cam means 140°Crank.

Fuelling

Fuel Map Mode1 to Mode 4 

The fuel map contains target AFR based on Engine Speed (RPM) and Engine Load (%). The vehicle has two factory fitted wideband sensors (one for bank 1 and another for bank 2). The ECU uses Fuel Trim Short Term B1 and B2 to ensure the target AFR is achieved during light load closed loop. Further to this the Fuel Trim Long Term Bank 1 & 2 will make long term adaption trim for continuous Short Term Fuel Trim corrections.

When Engine Load increases the fuelling will operate in open loop and the FTST feedback will not work and the Target AFR will not necessarily be achieved.

EcuTek have added to this factory Fuel Map with 3 extra new high resolution fuel maps (24x20) that can be calibrated for each of the Map Switch Modes. Mode 1 is the default fuel map if Map Switching is not enabled.

Cranking

The various cranking fuel maps can be increased or decreased to improving engine starting when using Ethanol or larger Injectors that may cause issues, the staged pulse width maps are an open time period in Ms and this global fueling period can be adjusted using the compensation maps. It’s generally suggested that all common maps are adjusted by the same % amount.

Fuel Map Enrichment Warm & Cold

The hot and cold fuel map enrichment maps are used to trim the desired AFR by a percentage to attain the correct AFR for a given RPM and Engine Load. The warm map works above 70 deg C and the cold below this threshold.

Values above 100% will cause the engine to run Richer, (e.g. 110% will be 10% more fuel than desired) and values below 100% will cause the engine to run leaner. This map can be used to fine tune for larger Fuel Injectors without having to alter MAF scaling.

Fuel Trim Per Cylinder

This map can be used to add extra fuel to certain cylinders, see the map help text for further information. We advise that the Injector Open Time is measured with an oscilloscope to ensure the correct Injector delivers the additional fuel, it appears that this map input axis shows cylinder numbers but it could be firing order. We hope to test and verify this in the near future. 

There are 3 separate modes for each DI injection pulse window (#1 = homogeneous injection first window) the 2 and 3 are for the stratified injection modes 2nd and 3rd pulse, if a change is required it will likely be relevant in all modes.

Over Run Fuel Cut #2

The Engine Speed must be over this RPM for fuel injectors to be cut during a period of deceleration (lift off over run). Only the #2 maps are used during our testing.

Over Run Fuel Cut Restore #2

This is the Engine Speed where the Fuel Injectors will be restored (turned on again). The Injector Open Time (ms) during overrun will never show zero and will be around 0.74ms, this is the Injector lag time period being shown but the injectors are not physically open. These values should always be at least 2300rpm above any target Idle speed (or the engine will stall on overrun). Raising these values to say 5000rpm when the coolant temp is hot will encourage pops and bangs during gear change and decal conditions. Only the #2 maps are used during our testing.

Injection Angle

The Infiniti VR30DDTT has a complex fuelling function, the use of the direct injection enables more accurate adjustment of fuel injection quantity by injecting atomized high-pressure fuel directly into the cylinder. The amount of fuel injected (controlled by injector open time) is determined in the ECM referencing the engine running conditions which are determined by input signals (e.g. engine speed, intake air volume, fuel rail pressure and boost pressure), primarily using the crankshaft position sensor, camshaft position sensor and the mass air flow sensor.

In addition, the amount of fuel injected is adjusted to improve engine performance under various operating conditions as listed below.

Fuel increase

• During warm-up

• When starting the engine

• During acceleration

• Hot-engine operation

• When selector lever position is changed from N to D

• High-load, high-speed operation

Fuel decrease

• During deceleration

• During high engine speed operation

As part of the emissions control and engine safety function implemented in the ECM Stratified-charge Combustion or Homogeneous Combustion have been implemented. 

Stratified-charge combustion is a combustion method which enables extremely lean combustion by injecting fuel in the latter half of a compression process, collecting combustible air-fuel around the spark plug, and forming fuel-free airspace around the mixture. The stratified charge can be split in up to 3 separate injection events, even during expansion strokes in some cases possibly to clean the 3 way catalyst NOx trap.

The use of the stratified-charge combustion method enables emissions-reduction when starting the engine with engine coolant temperature between 5°C (41°F) and 40°C (104°F). Right after a start with the engine cold stratified-charge combustion is used to heat up the catalyst as quick as possible.

Homogeneous combustion is a combustion method where fuel is injected during intake process so that combustion occurs in the entire combustion chamber, as is common with conventional methods. Except during start up with the engine cold, homogeneous combustion is used.

The fuel control functions on the VR30 engine we believe are per cylinder sequential (according to ignition order) selflearning and full time closed loop. Open loop fuel delivery is only used in very particular circumstances (like overrun and fail safe). The ECM uses the primary pre-turbo O2 sensors as well as the rear O2 sensors for fuelling adjustment.  There is a self learning function (short term and long term) as per all modern ECU’s, long term forming a form of wear and environment change adaptation and the short term handling instantaneous pulse width adaption.

Fuel Pressure

The fuel pump in a VK56-VD engine is similar to the VR30DDTT however is slightly different in the map layout and control strategy but seems to be common across the Nissan DI engines. Nissan specify a trigger point at which to start the outflow process to deliver the correct amount of fuel volume to maintain the correct pressure. The high pressure fuel pump is installed at the front of the engine bank 2 side and activated by the camshaft. The ECM controls the high pressure fuel pump control solenoid valve built into the high pressure fuel pump and adjusts the amount of discharge by changing the suction timing of the low pressure fuel.

The corrections for closed loop fuel pressure control are all modifiers to the outflow trigger angle. Below is a diagram illustrating how we believe that the pump control strategy and target maps work. The Fuel pump control - Base angle map is the ECU's initial point to trigger the outflow process. There are dead times, current targets and limits used as well, but these would only need to be changed if the pump solenoid is different, similar to what you would do if you were to change the injectors in other platforms.

The base angle maps give the start angle for the outflow process. The start angle (Fuel Pump Angle Target – Base) then has closed loop feedback corrections applied to it before the final value (Fuel Pump Angle Target) is used to trigger the solenoid. There are two closed loop feedback methods used and the directly work in degrees crank angle. 

There are

• Proportional feedback (Fuel Pump Angle Target – Prop)

• Integral feedback (Fuel Pump Angle Target – Int)

It applies the correction coefficients to the calculated fuel pressure error like below.

Feedback Correction Angle = Map Output x (Fuel Pressure - Fuel Pressure Target)

The correction angle values are directly applied to the base output value. If you find your actual fuel pressure does not match the target fuel pressure the first step is to adjust the base map, for example.

• Increase the angle to decrease stroke and delivered pressure

• Decrease the angle to increase stroke and delivered pressure

If you find that the Fuel Pressure does not meet the Fuel Pressure Target you can modify the proportional and integral factor maps at the required RPM to smooth out the delivered pressure.

The fuel pump solenoid is controlled in a peak and hold method. If you are calibrating a replacement fuel pump solenoid it’s likely you will need to adjust Fuel Pump Regulator Pulse Time and Fuel Pump Regulator Response Time.

If only the mechanical pump unit has been changed, the Fuel Pump Control - Base angle and associated PID maps will require recalibration and the solenoid maps can be left alone.  If changing the fuel pump solenoid you may need to alter the actual drive pulse characteristics to suit the physical changes to the solenoid, the drive current and voltage look a little like below, when changing the pulse characteristics use the below diagram as a reference.

The time period for each total pulse is set by the fuel Pump Regulator - Pulse Time. The hold component is set by the Fuel Pump - Hold Time Initial Value and the peak section is the difference between the total and hold section of the drive current profile. Peak and hold current can also be switched to different levels depending on engine speed if required.

Map List

Live Data Parameters

• Fuel Pressure Target (Mpa) - Fuel Rail Pressure target

• Fuel Pressure (Mpa) - Actual Fuel Pressure in High pressure fuel rail

• Fuel Pressure Sensor (mV) - Fuel Pressure sensor raw voltage

• Fuel Pump Angle Target (°)– Actual target angle for fuel pump solenoid trigger

• Fuel Pump Angle Target - Base (°) – Base map angle output value

• Fuel Pump Angle Target – Int (°) – Current integral correction angle output value

• Fuel Pump Angle Target – Prop (°) – Current Proportional angle correction value

Fuel Pressure Target / Fuel Pressure Target at Low Temp

There are two fuel pressure target maps, these are active dependent on high and low coolant temperatures. The output is in MPa and profiled for specific RPM and QH0. This value is used for the error calculation and fuel pressure correction function.

Fuel Pump Control - Base Angle

This is the crank angle at which the trigger pulse for the fuel pump solenoid is set.

• Increasing the angle reduces outflow and pressure •       Decreasing the angle increases outflow and pressure.

If the Fuel Pressure is not hitting the Fuel Pressure Target at the final Fuel Pump Angle Target displayed change this map to give more pump stroke to maintain pressure. Be aware that if the angle is set to high or low it will trigger the pump before on the inlet stroke and cause pressure issues.

Fuel Pump Control - Feedback Deadband

This is the pressure range in which the proportional and integral feedback of solenoid trigger angle will not become active.  In the example if the error is outside of 0.5 Mpa, the P&I correction will commence.

Fuel Pump Control - Proportional Factor

This is the proportional gain used to calculate the instantaneous absolute addition to the Fuel Pump Target angle.  Based on RPM, the feedback angle is generated using the fuel pressure error value multiplied by the proportional correction amount.

Fuel Pump Angle Target – Prop = Fuel Pump Control – Proportional Factor map output x (Fuel Pressure - Fuel Pressure Target)

Increasing the factor give more instantaneous correction for the same amount of fuel pressure error

Fuel Pump Control - Integral Factor

This is an integral gain factor map to calculate the cumulative addition to the Fuel Pump Angle Target.  Based on RPM, the feedback angle is generated using the fuel pressure error value multiplied by the proportional correction amount at the loop speed.

Fuel Pump Angle Target – Int = Fuel Pump Control – Integral Factor map output x (Fuel Pressure - Fuel Pressure

Target)

Increasing the factor give more correction and faster responding cumulative values for the same amount of fuel pressure error.

Fuel Pump Regulator Response Time

This is the dead / lag time of the pressure control solenoid, when changing pump solenoids this must match the dead time of the new solenoid installed. Like injectors, if tuned incorrectly it will effect the closed loop pressure control systems.

Fuel Pump -Battery Switching Time

At different battery voltages the ECU uses different times for switching between hold time initial values of the fuel pump solenoid.  Depending on what the battery voltage is, it will use the range specified on the Fuel Pump - Hold Time Initial Value map, see that map description for more details.

Fuel Pump - Hold Time Initial Value

When the battery voltage is above the top threshold of Fuel Pump – Battery Voltage switching Time the top row of this map is used, when between the top and middle threshold the second values are used, as per the second image.

Fuel Pump - Peak Current Initial Value

The target current (Amps) for the Peak driving phase of the pressure control solenoid. This could be adjusted to better suit increased current demands of an upgraded pump solenoid. The two values are for mode 1 and 2 as per the hold current maps and its believed these are switched by exceeding the thresholds Fuel Pump - RPM For switching Peak Current & Hys.

Fuel Pump - Hold Current 1 & Fuel Pump - Hold Current 2

Target hold current set to drive the pressure control solenoid.  Two maps are used for different modes but believed they are switched at the engine speed determined at Fuel Pump - RPM for switching Hold Current.  This could be used to cope wit hthe increased current demands of an upgraded pump solenoid.

Fuel Pump - RPM for switching Hold Current

RPM level at which the ECU changes from using the Fuel Pump - Hold Current 1 to Fuel Pump - Hold Current 2

Fuel Pump - RPM for switching Hold Hysteresis

Hysteresis value used when the RPM for switching hold current is reached.

Fuel Pump RPM for switching Peak Current

RPM at which the ecu changes from using Fuel Pump - Peak Current 1 to Fuel Pump - Peak Current 2

Fuel Pump RPM for switching Peak Hysteresis

Hysteresis value used when the RPM for switching peak current is reached.

Fuel Pump - Delay Time Switching Peak Current

The peak current drive for the control solenoid on the fuel pump.

Fueling (Target & Control)

Map List

Live Data Parameters

• AFR Average (AFR) – Bank 1 and 2 sensor values averaged

• AFR Average Calibrated (AFR) – Bank 1 and 2 sensor output using EcuTek Polynomial averaged

• AFR Bank 1 (AFR) – Bank 1 O2 sensor output as seen by the ECM

• AFR Bank 2 (AFR) – Bank 2 O2 sensor output as seen by the ECM

• AFR Bank 1 Calibrated (AFR) – Bank 1 O2 sensor output as seen by the EcuTek Polynomial

• AFR Bank 2 Calibrated (AFR) – Bank 2 O2 sensor output as seen by the EcuTek Polynomial

• AFR Sensor B1 (V) – Bank 1 O2 sensor output raw voltage

• AFR Sensor B2 (V) – Bank 2 O2 sensor output raw voltage

• AFR Sensor Heater #1 (%) – Percentage duty of Bank 1 O2 sensor heater

• AFR Sensor Heater #2 (%) – Percentage duty of Bank 2 O2 sensor heater

• AFR Target B1 (AFR) – Bank 1 target AFR

• AFR Target B2 (AFR) – Bank 2 target AFR

• Fuel Injection Angle (°)– OEM injection angle parameter

• Fuel Injector Duration B1(ms) – Injector open time on bank 1

• Fuel Injector Duration B2 (ms) – Injector open time on bank 2

• Fuel Injector End to Spark (ms) – Time between end of injection and ignition event.

• Fuel Trim Long term B1 (%) – Percentage extra injector open time applied by long term fuel correction

• Fuel Trim Long term B2 (%) – Percentage extra injector open time applied by long term fuel correction

• Fuel Trim Short term B1 (%) – Percentage extra injector open time applied by short term fuel correction

• Fuel Trim Short term B2 (%) – Percentage extra injector open time applied by short term fuel correction

• Injector Open Time (ms) – The injector open time of the last pulse used in the sequence

• Map Trace AFR (AFR) – Value used to map trace on fuel maps and ignition maps when colouring by AFR

Injector Comp (Mode 1-4)

The injector compensation maps work directly on the injector magnification values and as such directly effect injector open time during engine operation.  They are load and RPM scaled and as such can be used to adjust the total fueling under certain running conditions or compensate "Per Mode" for different fuel densities and mass flow rates e.g. Ethanol Fuels.

AFR Conversion Bank 1 & 2

There are many different OEM fuelling target selection modes, these are for functions used when trying to achieve high efficiency closed loop stoichiometric fuelling, low temperature cat warm up, limp modes and High Load running conditions. The AFR conversion tables are an offset adjustment to the output of the fuel maps (in equivalence ratio) to convert into AFR. While the exact reason for having a changeable Eq ratio to AFR conversion is unknown we suspect it is to do with “in cylinder mixing” or safety factors. 

These two maps, one for each bank, are used internally by the ECU to convert values in the main fuel map to bank specific AFR targets. The units are Equivalence Ratio and can be converted to AFR by dividing 14.7 by the values in the table, for example 1.00 gives an AFR of 14.7:1 and 1.336 gives an AFR of 11:1.

By default they do not give an output identical to the input, and it is different between each bank, and they typically translate values from the fuel maps at high load to slightly richer targets. To nullify this effect, set that the data values to exactly equal the input values, but be aware that the result is that the reported AFR target and AFR logging parameter will not match when long and short term fuel trims are 100 (no trimming).

This ends up with a setting that looks like the second image.

Stock Values

Revised Values

AFR Target - Max at WOT

This is the leanest AFR Target permitted for a given RPM when at WOT.  It could also be called "Leanest AFR for Best Torque."  Of the values returned by this map and the main 3d fuel maps, the richest value will be used by the ECU.  Raising the values in this map prevents rich AFR Targets from interfering with the intended target AFR typically used on high power cars with modified exhaust systems.  Setting all the values in this map to 14.7 will completely disable the effect.

Cranking

There are many cranking maps and this function is not well understood at this time.  There are set pulse widths for cranking phases with references to coolant temperature as well as after-start enrichment periods.

Injection System

There are 4 pulse modes and 3 injection windows, these injection modes relate to which windows are used, the 4 modes are

• Homogeneous Middle Pulse Mode

• Homogeneous Pulse Mode

• Stratified Pulse Mode

• Pre-Injection Pulse Mode

The 3 windows that are used are an early, a middle, and a late window, and these have different start and end angles set in the software. The modes and windows are all decided “per injector” sequentially.

Fuel injection timing (injection Angle 1, 2 & 3 in deg) Indicates the fuel injection timing computed by the ECM according to the input signals. There are 3 windows for injection events and it has been seen that at low RPM and peak torque these different windows are used mostly. This is to improve emissions and mitigate low speed preignition events that can occur. When using Homogenous injection strategies Injection Angle 2 is used mostly, 

NOTE: Injection Angle indicates degree of start of injection from TDC of intake stroke (After Top Dead Center). The diagram below shows the relationship between injection angle and combustion cycle.

Map List

These tables will be released in the near future though the names may change.

Live Data

• Injection Pulsewidth 1 Cylinder 1-6 - The injection timing of pulsewidth 1 in milliseconds for each cylinder

• Injection Pulsewidth 2 Cylinder 1-6 - The injection timing of pulsewidth 2 in milliseconds for each cylinder

• Injection Pulsewidth 3 cylinder 1-6 - The Injection timing of pulsewidth 3 in milliconds for each cylinder

As described in the introduction, the injection timing maps set the angle after TDC of exhaust/intake stroke. The output values are in crank degrees and they are set by engine speed and a calculated load condition using multiple variables to generate the output value.

There are many different modes in which different injection windows are used and different injector “start of pulse” angles are chosen, these are for High power low temperature or SCV position.

Injector Characteristics

Direct injection (DI) characteristics are quite complex but can be broken down into several controlling functions. The injectors are driven at a high voltage for a short time using the high-pressure fuel supply to achieve the required quantity in a short period. The ECM is equipped with an injector driver unit that drives the fuel injector at approximately 65 V (maximum) to increase the speed of injector opening thus increasing the operating window available.

Injector characteristics are split into pressure groups like the following.

• High Pressure failure (pressure to high)

• High pressure

• Normal pressure

• Low Pressure

Each pressure mode has its own set of injector characteristic maps (including peak and hold currents, switching times and delays). The opening time is calculated using these values which are further split into the phase of the injector driving cycle. There are 2 main phases, a peak current phase to drive the injector open and a hold current phase to keep it open. The final pulse width is subject to low pulse width linearization maps and minimum open times.

Injector Magnification

The injector flow differs at different fuel pressures.  To compensate for this, the response time of the injector can be modified for fuel pressure using the Injector Magnification map.

• Increasing the value will increase the calculated fuel amount required.

• Decreasing the values will decrease the amount of fuel calculated for the current conditions.

Injector Lag Time

The OEM injector lag time (latency) is not defined like a typical injector, it is set to 0 and then the compensation tables used to determine the correct lag time 

Injector Minimum Open Time

The OEM injector lag time (latency) is not defined like a typical injector, it is set to 0 and then the compensation tables are used to determine the correct lag time

Injector Lag Time FP Compensation

The axis of this map is fuel pressure and the output in milliseconds.  These are added to the 0ms base time in order to form a lag time value.

Injector Narrow Pulse-width Linearization Compensation

Direct injectors do have a non-linearity characteristic much like port injectors.  The low pulse width linearization maps are split into fuel rail pressure modes and injector drive current phases.

The chart to the side explains the map functions, they should only need to be adjusted if aftermarket injectors are fitted.

Fuel Pressure High Target - Idle Threshold (1D)

These 1D values are used to interpolate other values.  They are compared to the current fuel pressure value and the difference between the respective threshold values.  The difference sets the interpolation factor between the 2D narrow IPW Target Fuel Pressure -Pressure maps as per the diagram above.  These values will not need to be changed unless the injectors have been upgraded.  The injector supplier should give these values if required. 

These tables and the similar tables use the interpolation amounts of the 1D pressure thresholds to set the desired addition to pulse width. There are 2 or three maps per mode shown in the diagram above. They have initial injector open time as the input and output a value to add to this current injector time. These values will not need to be changed unless the injectors have been upgraded, the injector supplier should give changes to these values if required.

Injector Current Characterization

The injectors are driven in a peak and hold fashion per fuel pressure mode, there are individual times currents and delays involved for each of these modes, the modes are

• High Pressure Failure

• High Pressure

• Normal Pressure

• Low Pressure

The current drive pattern is the same as most other injector drivers and is roughly represented to the left.

The pressure mode map list consists of the maps below, there is a tree for each pressure mode.

Pressure Threshold

Threshold for fuel pressure being too high, when this value is achieved the fuel pump current is adjusted.

Injector Current Switch Pulse Width

Initial Peak time switch point where the injector drive switches from peak to hold mode.

Injector Delay Time Initial

Initial delay timer for the total pulse to start

Injector Hold 1 Current Initial

The target hold current for injection mode 1

Injector Hold 2 Current Initial

The target hold current for injection mode 2

Injector Hold Time Initial 

The initial time of the hold current phase.  If the total pulse duration isn't long enough, hold pulse won't be used.

Injector Hysteresis Initial

The target peak current during the peak drive phase.

Injector Peak Current Initial

Hold delay time for injector mode 2.

Injector T2 Delay Time Initial

Hold delay time for injection mode 2

Idle

Idle Target #1 & #2 (Drive and Neutral)

The Idle Target maps are used to control the engine speed for drive and neutral gear shift position. It is advised that you adjust both the maps to the same value to avoid discrepancies in the idle speed.

While not defined fully the 370Z uses a similar idle control strategy to the GTR where it calculated idle airflow in l/min and makes closed loop correction within a deadband. This all starts with the base airflow to engine speed demand map, if you cannot achieve adequate idle control with just these map please contact support@ecutek.com for more definitions.

There are also ignition timing maps for base igntiion timing during idle that are available to help set the timing when the ECU is in closed loop idle control mode and corrects ignition tiing to keep the idle stable. Keep in mid that idle control ignition is used when in decel fuel cut as well.

The GTR idle control strategy is outlined here. GTR Idle Control

Ignition

The OEM ignition timing strategy works very well when applied to a stock car. However when moving on to a high power application, it can be difficult to work with and restrictive. RaceROM adds easy to use larger maps that boast a high precision load input axis for improved control and range. Additional supporting maps were also added for further safety.

The VR30DDTT platform uses a maximum Best Torque (MBT) timing ma, a base map (knock limited) and an ignition timing maximum allowed map to determine the base timing. It will choose the lowest value of the Base MBT or Max map and then apply the engine condition corrections and the knock detection correction amounts.

There is a safe mode (low octane) map that can be switched to if the car enters limp mode (From DTC's) or high knock levels have been sustained for a set period. The safe mode can sometimes be enabled if the vehicle is refueled but that is yet to be confirmed. The diagram below illustrates the basic control functions and major inputs however there are additional maps and parameters that go in to the system.

Live Data Parameters

• Ignition Timing Base (°) – Current base ignition timing in degrees BTDC, negative means ATDC

• Ignition Timing Base lookup (°) – Current ignition timing map output in degrees BTDC, negative means ATDC

• Ignition Charge air correction (°) – Current ignition timing correction for CAT degrees

• Ignition Final (°) – Current actual ignition timing in degrees BTDC, negative means ATDC

• Ignition MBT (°) – Calculated MBT ignition timing in degrees BTDC for use in Torque Calcs and max Limits

• Ignition Timing (°) – Current actual ignition timing in degrees BTDC, negative means ATDC

• Ignition Timing Correction (°) – Ignition timing correction amount

• Knock Retard (°) – Offset due to knock, negative is retard, positive is dynamic advance on GEN 2

Knock Retard

Introduction

The VK56-VD and other Nissans (GTR and 370Z have very similar maps and strategies) have an active knock control strategy that involves use of the knock sensors in a constant feedback loop to generate and octane rating estimate and then apply ignition timing retard based on this active octane estimate and the drop from a the current running total.

The dynamic advance portion of this function is the ability for the system to measure the current octane rating of the fuel based on the knock sensor output and if no knock is detected it can add ignition timing (up to a maximum octane limit) until it detects enough knock maximising performance.

EcuTek have significantly re written the timing strategy on VK56 (GTR and Juke as well) so that it is far simplified (uses a single 3d map instead of an array of octane offsets and corrections) but have kept the octane drop and instantaneous knock retard functionality included.

for more information on how the knock control and octane estimation system works see the following link 370Z Knock Control, dynamic advance and Octane Judgement

As well as four hi-res Ignition maps we have also written four hi-resolution ‘Knock Control Enable’ maps which are used to enable and disable the knock control against RPM and Load. We suggest to enable the Knock Detection at high RPM so that the ECU can use active knock correction past 6000rpm as shown on the left in this screen shot below.

With the standard knock switched off past 6000rpm the ECU will hold that knock retard to the rev limiter but if we allow knock detection to take place at high RPM then the ECU will build out any negative knock retard at high RPM (assuming the knocking has stopped).

The Knock Sensitivity map can also be altered to raise the knock threshold where the ECU will determine a knock retard value is required. Each row is a cylinder number and the values in the map are the threshold.

Raising these maps by 5% (or maybe 10%) will make the ECU less sensitive to knock retard but you MUST always check for detonation with a  3^rd party device.

RaceROM offers Per Cylinder Knock and Per Cylinder Knock Threshold logging ability to aid this calibration process and help identify noisy cylinders so the threshold can be raised without raising the other more quiet cylinders. Considerations should be made for logging speed that is available from the factory ECU, not every knock event can be shown in the sampling rate that’s available.

The Knock Retard Multipliers can also be increased and decreased to provide a global gain on the output of the knock sensors but as above you MUST ensure you check for detonation with det cans or a similar knock detection device.

Map List

Ignition Timing IAT Comp (RaceROM) 

This additional EcuTek RaceROM map can be used to advance and retard the Ignition timing based on Intake Air Temperature, it can be used when running a ‘blow through’ MAF setup when IAT measures Charge Air Temp or when Speed Density is enabled.

Knock Control Enable (RaceROM)

These maps can be used to turn the knock control ON/OFF at different RPM and Load for each of the 4 different Map Switch Modes.
A value of 1 indicates Knock Control is active at that RPM and Engine Load.
A value of 0 indicates Knock Control is NOT active at that RPM and Engine Load.

Knock Sensitivity  

This per cylinder threshold map is the point where knock correction will become active for each cylinder. If the values against RPM are breached then the knock correction parameter will start to show knock retard. Built engines often generate excessive engine noise that can be detected as knock, raising these values will help prevent this being detected as knock though care must be taken that the sensitivity will still show true knock! The centre two cylinders are noisier due to cylinders either side (1-3 or 4-6) so the noise thresholds are higher.  See the tuning section for more information. 

Must be used with caution and understanding!

Dwell Time

Dwell time control on the VK56 are very similar to the GTR, please refer to the notes in the below article to tune these maps.

GTR Dwell Time

Limiters

Rev Limit - Fuel Cut

The Engine Speed at which the ECU will cut the Fuel Injectors, this is a hard cut rev limiter, set all values the same. The Input axis to these maps is currently unknown.

Rev Limit – Fuel Cut Restore

The Engine Speed at which the fuel injector will be restored after the Fuel Cut, set all values the same. The Input axis to these maps is currently unknown.

Rev Limit – Fuel Cut Maximum

This is the maximum Rev Limit, the top value is when the Fuel Injectors will be cut, the lower value is when the injectors will be restored. These values should be set the same (or above) the 2d maps called Rev Limit – Fuel Cut and Rev Limit – Fuel Cut Restore

Speed Limiter - Throttle Cut On/Off

The Vehicle Speed at which the ECU will close the throttle to maintain a target vehicle speed. The Throttle Cut Off value is always set high so we advise to keep it this way. 

Speed Limiter - Fuel Cut On/Off

The Vehicle Speed at which the ECU will cut and restore the fuel Injectors to maintain a target vehicle speed. It’s not advised to use the fuel cut method of speed control.

Sensor Scaling

MAP Sensor

The MAP is located in the Inlet Manifold, it’s a 1 bar sensor and there is a simple ‘bar per volt’ multiplier, the MAP Sensor Offset will be added to the ‘bar per volt’ pressure reading. Please note that the Offset value cannot be a negative value.  There is a second MAP sensor located in the Brake Boost pipe and this is used to measure Brake Servo pressure during cruise conditions, the ECM will close the throttle and create a depression should the servo pressure become too low.

Coolant and Intake Air Temp Scale

This map can be used to rescale the Coolant and Intake Air Temp sensor voltage to temperature scaling.

MAF Sensor Scaling (% to g/s) for Load

When fitting larger MAF housings (or Induction kits) then this value should be increased proportionally relative to the surface area increase of the larger MAF housing,  (MAF sensor diameter of stock 370Z should be 60.5mm)

This is a coarse adjustment for MAF scaling, it converts the MAF sensor % value into grams of air per second. See the tuning section for more information on adjusting this parameter.

Some forced induction setups may cause DTC and DTC conditions that do not illuminate the DTC.  With larger MAF tubes and if you exceed 4.85 MAF volts you may need to disable various MAF related codes, P0100 through to P010D. 

MAF Sensor Scaling Bank #1 / #2 (V to %)

These maps should be used to fine tune the MAF sensor scaling after the MAF Sensor Scaling map has been calibrated. When fitting larger Intakes it is critical that the MAF scaling on both banks are corrected. The value in the map is percentage of 100% Mass Air Flow, this is then multiplied by the MAF Sensor Scaling (% to g/s) 1D value to give a Mass Air Flow in g/s.

100% Engine Load

The point where 100% Engine Load will be achieved, this is factory set at 39.8 Base Fuel Schedule (BFS), increasing this map will advance ignition timing and reduce the Torque Actual output value so Ignition and Torque map rescaling must be made accordingly.

EcuTek RaceROM allows the engine load to scale well past 100%. It is not recommended to adjust this map.

BFS Multiplier (K-Factor)

This multiples Mass Airflow into Engine Load. This has been used in other software suites to rescale the MAF Tube size. It is recommended that the map not be altered unless you are constrained by an engine load limit. In all other cases, leave this set to its default value of 26806. Use the 1d map called ‘MAF Sensor Scaling (% to g/s) for Load’ for larger MAF Tubes and aftermarket Intake rescaling.

Torque

Torque Demand

This is the torque demanded (Nm) by the driver using the Accel pedal. 

This can be used to influence Auto gearbox control, see the tuning section for more info.

Torque Demand – Trustful

This is a check map for Torque Demand and must be set the same or a DTC condition will occur.

Torque Demand Multiplier

This is a coarse multiplication for torque demand used to smooth out transition periods. The default maps are calibrated to provide extra torque during pull away to prevent the car bogging down. This can be used to influence Auto gearbox control, see the tuning section for more info.

Torque Actual

This is the calibrated torque output of the engine, measured in Nm. It is important that the figures in this map are correct as it can seriously affect the driveability of the car, especially on the automatic transmission models which use the torque figures to control the TCM.

If the TCM is slipping then increasing these values should make it more firm and lock up quicker. Conversely If the gear change is hard, reducing these values will make it softer and allow more slip between each gearshift.

Torque Filtering WOT Hi (including the Trustful)

WOT is Wide Open Throttle, this map will prevent the Throttle from fully opening at low RPM.

Torque Filtering WOT Lo (including the Trustful)

WOT is Wide Open Throttle, this map will prevent the Throttle from fully opening at low RPM.

Misc.

Traction Control ESP

The factory ESP system will act as a traction control by closing the throttle butterfly should a wheel slip event occur.  If you alter the four TCS maps (as per the help text on the individual maps) then the throttle will no longer close if wheel spin occurs, use with caution!!

We recommend that you use the factory supplied ESP to turn off the ESP (traction control).

Radiator Fan Control Radiator Fan Duty

The fan duty for the current Coolant Temp and Vehicle Speed (A/C Off).

Radiator Fan A/C ON

The map output will be fan duty for the current Coolant Temp and Vehicle Speed (A/C On).

Radiator Fan A/C Related

This additional fan control map is used in alternate circumstances and is related to AC control.

Gear Ratio Gear Ratio Manual and Auto Transmission

When a taller Final Drive has been fitted the factory Sync Rev feature will not work correctly, simply increase these gear ratio values relative to the Final Drive percentage increment amount.