VW AG EA855 Engine Tuning





VW AG EA855 Engine Tuning



Introduction

The EA855 Gen 3 (EA855.3) is a global engine suitable for MLB (Modularer Langsbaukasten/Longitudinal ) and MQB (Modularer Querbaukasten/Transverse) platforms, capable of meeting the latest emission and fuel economy targets in different markets


Engine and Gearbox tuning for the following models with the MED 17.1.62 ECUs and DQ500 DSG gearbox:
2017 - 2020 - 8V RS3 EUDM and USDM
2017 - 2020 - 8S TTRS EUDM and USDM
2019 - 2020 - F3 RSQ3 EUDM and USDM

Note: DAZA calibration codes for USDM and RoW, DNWA for OPF Calibration codes EU 6d

https://mailchi.mp/ecutek/ecutek-launch-vag-mqb-ea-855-23-dq500-tuning-suite-incl-racerom?e=ca7315521c



Summary of Software

ProECU software has been introduced to allow reprogramming of the factory ECU in order to tune the necessary components of the calibration, allowing for modifications and increases in power.  Pro ECU software filters several thousand OE calibration maps into a comprehensive set of maps, selected to all allow the tuner to tune the engine with similar ease, found on a standalone replacement ECUs.


The software allows easy control over most factory parameters including:

  • Boost targets and wastegate control

  • Target AFR

  • Ignition timing and knock control

  • Valve timing and lift control

  • Fuel delivery including fuel pump calibration (using the same style pump as OEM)

  • Airflow Measurement and fuel compensation



Tuning should be carried out by suitably trained individuals.

Use this document is a guide. Changes to any calibration is at your own risk.

Changes involving the evaluation of full engine load, should be carried out in the safety of a chassis dynamometer by trained personal.

The base engine should be deemed in a serviceable state of health as well as the dress kit bolted to it before attempting to tune it etc.

For the best results, ensure the engine is run on the best commonly available fuel (in the EU, RON 98 or greater)

This document is also work in progress.




















Programming 

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

For more software guides check out:












Tuning Guide & Example Changes

The MED 17.1.62 Engine Control Unit (ECU) requests and outputs torque via a fast path and a slow path.

The fast path includes the following attributes.

  • Ignition control.

  • Fuel setpoint and lambda control.

  • Fuel shut off.


The slow path includes the following  attributes.

  • Load demand via air setpoint

  • Throttle setpoint

  • Turbocharger actuator set point.

  • Cam setpoint.



Tuning the ECU for more power involves several operations and involve raising the load limits on the slow path and optimising the fuel and ignition settings on the fast path.







 



 

Torque and Cylinder Fill Determination

Airflow determination comprises of several calibration tables that allow the load of the engine to be increased for a given set of engine speeds.
Increasing the boost via an increase in air mass set point can be summed up by the following illustration.

 

Driver requested torque This is a the output of the Driver Demand Pedal maps, the torque limits are applied to this value.  The driver torque request is often scaled to be nonlinear by the manufacturer with a leading edge at the low pedal low rpm breakpoints to demand a little more torque when driving off.

There are many pedal based torque demand maps and they depend on the driving mode of the vehicle (i.e Eco, Normal, Sport) and the gear (1-4th and above), as well as the vehicle \ transmission type.

Below is a comparison between the stock and example ROM Driver requested torque map. the map has been recalibrated to be more linear until full accel pedal values where it targets a higher torque demand from 85.4% accel pedal.

 

Important Logging Item Accel Pedal Position%

The output of the Driver requested Torque - Pedal maps is then multiplied by the MAX indicated torque maps for the vehicle region and the running mode including Valve Lift. The correct maps for the tuned vehicle can be adjusted to profile the maximum torque demand the driver request can deliver.

It is important to pay attention the the maximum desired torque at low loads as when this is increased the idle torque calculations can hold much more torque in the slow path and then need to retard the ignition to compensate for the higher airflow causing idle fluctuations etc. below is a Max Indicated Torque map from the example ROM.

 

The above table was set at a desired maximum beyond stock globally i.e. for every gear and engine speed set point.  The overall maximum final Indicated torque is then limited by the Maximum Indicated, Normalised Indicated, Multiplex and Maximum Engine Torque at crank.

 

In the example ROM these are set out of the way at 800Nm an 99.2%. 

The output of that table after losses at the clutch are added to create combustion torque set point or indicated torque set point, is used on an axis of a 3D table to set the Cylinder fill target of the engine.

 

Indicated torque, deduced from the Maximum Torque tables, feed into  Reference Air Charge. There are several of these tables, based on the position of the port flaps, valve lift, and the camshaft position of inlet and exhaust.

At wide open pedal (WOP) with the intake flaps lowered (open), valve lift and the camshafts at their end stops. The indexing will be - Open flap - No Lift - In1 - EX1, whereas at light loads, for example at 2500 rpm, the intake flaps will be raised (closed), the exhaust only AVS will be in lift and the camshafts can be in overlap, this will result in a Reference Air Charge table with the index - Closed flap - Lift - In3 or In2 or Ex3 or Ex2 being utilised.

A typical example of Reference Air Charge taken from an example rom of the Ecutek Golf 7 R shown below.

 

 

Indicated Torque at Reference Conditions

Logging Item - Torque Actual at Clutch

Should be set to not limit reported engine torque used to calculate clutch pressure in the DSG>  This is set up to a maximum at higher airflows.

Logging item Air Mass Charge from Manifold, Air Mass Charge Setpoint

 

With the airflow setpoint determined, the output of the Refence Air Charge table, air mass in mg/stk,  is used as an axis for ignition setpoint tables (which will be covered later) and is also converted into intake manifold pressure, used as an axis for determining pressure upstream turbo limits. As mentioned in the previous slide, there are several Reference Air Charge tables which are indexed by active port flaps, valve lift, intake/exhaust cam position.

Once the Refence Air charge tables and Maximum torque tables are set high enough to achieve desired pressure upstream of the throttle, the boost setpoint offset table can be calibrated. All boost calculations are derived from the Refence Air charge tables and Maximum torque tables.

Typical Boost pressure offset table shown below derived from Mass Charge from Manifold and Air Mass Charge Setpoint .

 

 

The turbocharger feature on the EA888 as certain sub features modelled to determine turbocharger speed, turbo pressure ratio and the wastegate position for a desired pressure upstream throttle.

To achieve the desired boost beyond standard, the limit for turbine speed must be increased to avoid any limiting errors.  WG position tables usually remain as default for calibrations based on standard hardware.  For hybrid turbos, errors in desired WG position, causing an under or overboost condition require some tuning of the WG PID and position set point tables to ensure the WG actual position is the same as the setpoint.

Logging items - Pressure Upstream Throttle, Manifold Absolute Pressure, Wastegate Position, Wastegate Position Setpoint, Exhaust Pressure Flow Factor, Intake Pressure Flow Factor, Turbine Actuator Proportional/Integral, Turbine Actuator Final Value ,Turbo speed/setpoint.

 

 

 


Increase the Limits

Setting proper limits on what the engine can and can't do is an important step to start with.  In some cases the limiters will step in when you attempt to make additional power which can slow or even halt forward progress on a tune.  The important thing to remember is that these limiters aren't just in place to stop you from making power.  They exist to protect various vehicle components and some common sense should be used when raising them.  For example raising the allowed Exhaust Gas Temperature to high can lead to a shorter life span on the vehicle's catalyst etc.

EGT

  • EGT Maximum Relates to the maximum catalyst temp and is set at a factory 950 deg C

  • EGT Limit for Overheat Protection Relates to the turbocharger turbine protection


Rev limit

  • Engine Speed Maximum Set as desired from factory default of 6800 rpm

  • Engine Speed Limit for Stationary Vehicle AUTO/MT/DCT, usually set at ~ 3800 rpm from factory

  • Engine Speed Limit for VVL System High/Low/by Gear Set to match Engine Speed Maximum   factory redline.

Throttle Pressure ratio Limits

  • Throttle Pressure Ratio Threshold for WOT - To force the throttle open to WOT, you need to reduce the pressure ratio around the point where there is just about positive pressure.
    It will need to be blended and refined from the example below, to not have the throttle slam open at light loads or pullaway

Air limit

  • Maximum Air Intake Volume 1/2 ( No lift or Lift) Set to a maximum beyond what is output from   Reference Air Charge.

  • Maximum Cylinder Air Set Point Alter if more than 2000 mg/stk is to be consumed through the engin




Intake pressure limit

  • Manifold Pressure Set point Limit Set this value higher than the highest desired boost   expected in the manifold. Default is 3000 mbar ( 2 bar gauge)

  • Maximum Intake manifold Pressure Setpoint Set this value higher than the highest desired   boost expected in the manifold. Default is 2500 mbar ( 1.5 bar gauge)

  • Minimum Charge Air Pressure Quotient Too High for Diagnosis Adjust to clear maximum boost   achieved.




PUT to Intake pressure deviation limit

  • Maximum Boost Deviation for Charge Pressure too high Set to ensure transients into target   boost has enough head room.

  • Charge Air temperature Limit

  • Intake Air Temp Threshold for Torque reduction Turbo Charge Air temperature threshold -  To   be raised due to operating higher operating pressure ratios.

  • Intake Air Temp Threshold setpoint for Torque reduction Turbo Charge Air temperature   threshold set point. To be raised due to operating higher operating pressure ratios.




Turbo limits

  • Minimum Torque for Turbo Overheat Protection Option to set higher than stock.

  • Turbo speed Max Recommendation to set beyond 176K rpm.

  • Turbo speed Max for protection Recommendation to set beyond 161K rpm.

  • Turbo Pressure ratio limit Set to beyond target PR.




Maximum indicated torque limit

  • Maximum Reference Indicated Torque Set this to a maximum.


Basic indicated Maximum TQ Full Ld - Power Class 1-5

  • Basic indicated Maximum TQ Full Ld - Power Class 1-5.  Set these maps to a maximum on some Cal ID's they will be set at 1024Nm as standard.

  • Basic indicated Maximum TQ Full Ld - Gear Spread 1-5.  Set these maps to a maximum on some Cal ID's they will be set at 1024Nm as standard.

Vehicle Speed limit

  • Vehicle Speed limit All. Set to desired maximum.









 



 

Optimise the Ignition Timing.

With the Airflow and boost settings elevated for more performance, optimisation of ignition setpoint will become necessary to ensure the engine can be operated safely between broadline det (BLD) and maximum brake torque timing (MBT).

The EA855 Bosch ECU has two important sets of ignition tables.  The basic ignition angle or Ignition Angle and the MBT ignition angle or Ignition Ref Angle.

The Ignition Ref Angle is set during OE development and represents the theoretical maximum ignition setting on a reference high octane fuel, with a lambda efficiency of 1. It shouldn't require much if any alteration on calibrations involving standard hardware. It also takes part in ignition efficiency calculations.  The final ignition setpoint will be determined by experimentation in the ignition Angle tables.

There are several Ignition setpoint tables for both Ignition Ref Angle and Ignition Angle, which are indexed by active port flaps, valve lift, intake/exhaust cam position.

At wide open pedal (WOP) with the intake flaps lowered (open), valve lift and the camshafts at their end stops. The indexing will be - Open flap - No Lift - In1 - EX1, whereas at light loads, for example at 2500 rpm, the intake flaps will be raised (closed), the exhaust only AVS will be in lift and the camshafts can be in overlap, this will result in a Reference Air Charge table with the index - Closed flap - Lift - In3 or In2 or Ex3 or Ex2 being utilised

A typical ignition table for WOP is shared in the illustration below.

 





Logging items – Ignition 1 to 4





Optimisation of knock correction.

Knock detection and control is usually a feature that is designed during a lengthy OE process involving hours of design validation on an engine dyno, which is then tested on various market place fuels and climates and involving Tier 1 grade combustion analysing equipment.

The knock control feature, allows each cylinder to be optimised by allowing the cylinder to operate safely and as close to MBT as possible and thus maximising torque while reducing the spark spread across the engine cylinders.

This feature also has benefits of reducing engine roughness and improving fuel consumption while delivering the best engine response.

Depending on engine modifications and loads, detection integrals can be optimised as well the step changes to correct for a knock event when running boost levels beyond the factory set point of 2200 mbar.

Tables that will commonly be revised are:

  • Knock Detection - integral correctional increase.

  • Delay Before Dynamic Knock Speed. Transient knock sensitivity

  • Delay Before Timing Increase in Fast Mode

  • Knock Retard Increment

  • Knock Retard Decrement

Logging Items - Knock Retard 1 to 4



Reviewing ignition compensation tables

  • Ignition Angle Base - Correction for all combustion modes.

  • Ignition Angle Correction Combustion mode 2 - FSI double injection ignition correction.

  • Ignition Angle Intake Temp Corr. - Ignition correction for manifold temperature increase.















Tuning the Lambda Set Point. (Air Fuel Ratio)

On the EA855 engine, a lambda set point of 1 is targeted for the entire operating range.  Featuring a piston design which is profiled to suit direct injectors and an optimised combustion chamber design, lambda 1 is achieved at spark plug, for engines operated at factory load limits.

To achieve optimum power with greater cylinder pressure, a richer lambda set point is recommended.  Lambda setpoint can be influenced by high intake or catalyst temperatures, as well as turbo protection tables. So these tables will have to be altered in a safe manner to suit the new fuel target.

Optimum settings between LBT (Lean Best Torque) and RBT (Rich Best Torque) should be determined by experimentation.


Logging items - Lambda Actual, Lambda Target













Setting The Ideal Camshafts Transitions and Valve Lift.



The factory camshaft setpoints can be further optimised to increase midrange torque.
This is with lift or without.

An experiment involving setting individual cam tables i.e. the exhaust bank or the intake bank at a time, to global settings at high air flow set points and all engine speed set points, can be used to find the best setpoint at various engine speed break points.
The results of the experiment can be blended into the cam set point tables for the best full load curve.



    



Logging items - Intake Cam Absolute Position, Intake Cam Absolute Position Setpoint,     Exhaust Cam Absolute Position, Exhaust Cam Absolute Position Setpoint


Valve lift is usually zero after ~2600 rpm and high airflows



Logging Item - Valve Lift Setpoint.









Map Description and Control Functions

Boost Control

Like all Modern ECU the MED17.1.62 is based in torque interpreting driver inputs to determine a torque requires which is then turned into both fast and slow path torque demands which in turn are then turned into airflow targets and then Manifold Pressure (MAP) targets which are finally used to set the boost pressure targets. the WG control solenoid on the ea855 engines is a normal 3port Peirburg valve collectively know as the N75 valve.

Boost Target Control

As previously mention, the boost target comes from the manifold pressure target (similar to the ea888 engines) but is adjust for various limits and actuator positions like throttle. the manifold pressure target is derived from the target cylinder fill and the calculated current volumetric efficiency with pressure offsets for cam overlap and exhaust gas back pressures. the general overview is below, for more details on specifics please look at the respective sections of this guide.

 

WG Position and Duty control

Boost control in the ea855 is done in a closed loop fashion using Proportional, Integral and derivative corrections to keep the boost actual on the boost target. there also appears to be some learning / adaption for WG duty that are applied to the base WG value to keep the PID controls at an acceptable level. there are also linearization tables for converting the WG control duty to WG duty final output presumably to allow for different types of Periburg solenoids.

 

Turbo Protection Functions

The ea855 engine has several turbo protection function, these functions are designed to protect the turbo from damage they are used to reduce the boost target throw DTC’s or adjust the WG duty protecting the turbo from excessive pressures, there are further limits in the cylinder fill functions for protecting internal components from high boost pressure or the RaceROM boost limit fuel cut can be used. The Turbo protection functions used are

Turbo Pressure ratio Charge temp & Overspeed limits

These maps limit the boost pressure target so that the turbo speed does not exceed the OEM calibrated safe turbo speed, they are a pressure ratio so includes atmo pressure and intake pressure drops when being turned into a pressure target limit. These map is generally raised to allow for higher boost targets

Pressure Ratio for Turbo Charger Overspeed

Pressure Ratio for Air Charge Temp.

Turbo surge protection

This map is a pressure ratio limit similar to above that when the volume flow decreases while the pressure is high the boost pressure target is limited to this value (pressure ratio) to prevent the turbo compressor wheel reaches a stall airflow conditions and potentially damaging the turbo.

Max Pressure limits

These values are limits or values that are used in place of a pressure measurement above the limit, if you are raising the target boost above these values you will need to increase them to above your maximum boost target.

Maximum Intake Manifold Pressure

Max Pressure Replacement intake Manifold

Max Pressure Replacement Pre Throttle

Pressure Delta thresh. For detecting Overcharge 1, 2 & 3

When the values in this map are exceeded an error state is triggered and a limp mode is set. The input is Boost error and the output values are the boost controller pressure deviation and are used as the threshold to set the error mode.

Burble

Cam Timing

Cylinder Fill Control

DTC, Monitoring & Diagnostics

Exhaust Flap

Exhaust Temperature Modelling and Correction

Fuel Shut Off

Fuel System

Fueling

The ea855 platform utilises full time closed loop fuel control with both Port and Direct injectors employed. the systems are based on lambda 1 targets (no OEM map provided) unless other functions such as component protection, catalyst temperature protection, after start enrichment, full load enrichment, catalyst purge or heating are required where it will switch to different fueling and injection strategies.

Lambda Target

the overview of the lambda target system is below, for specifics of correction or limitation systems please see the descriptions for those functions

 

The Key to increasing power with alternate fuel targets is the use of component protection fueling strategies, specifically the EGT triggered strategies. These Lambda Component Protection maps are available as RaceROM maps per map switch mode as well,

These maps are set quite rich stock and gains have been found by increasing the lambda target. when tuning, use the RaceROM map switch mode specific values as these will overwrite the OEM map values.

The EGT threshold for using the component protection maps can be adjusted to force the ECU to run these maps full time. In the example ROM the egt thresholds are set to 300degC.

These maps are set at various values in the example they are all set equal.

There is also maximum and minimum Lambda target values the Minimum Lambda for combustion is the lowest value for target Lambda that the ECU can use.

MPI_DI Split

Idle Control

Ignition TIming

Injection

Injector Scaling

Injector Timing / Phasing

Knock Control

Limiters

Sensors

Torque Control

Valve Lift

 



Glossary of Tuning Terms



EcuTek ProECU tuning tools 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, 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 **



Retail customers

** If you have any doubt that you do NOT have the experienced required to use this product then you should NOT USE IT, you should simply contact your EcuTek Master Tuner shown clearly on the top of your Programming Kit or visit your preferred tuning shop to have a professional tuner to use it for you **Â