POR-009 Tuning Guide

Porsche Macan S

Porsche Macan GTS

Porsche Macan Turbo


Tuning Guide and Table Definitions

This tuning guide is broken into the basic components of tuning a Porsche Macan and the tables associated with each of these components. Due to differing tuning strategies available currently the Macan S/GTS and Macan Turbo are broken up into two seperate boost control strategies.  We hope to refine these as strategies as we continue our development with the platform.  This guide outlines basic tuning strategies and defines tables for each major tuning category, such as boost control, fueling, ignition timing, etc...

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

The first step in tuning a Porsche Macan is choosing a COBB Tuning Off-The-Shelf (OTS) calibration that most closely matches the modification level and fuel available for the vehicle to be tuned
The Stage1 calibrations are designed for vehicles with no aftermarket parts at all. Stage1 are the only OTS maps offered at this time.  

Step 2 – What fuel is the vehicle using?

Note that COBB Tuning offers calibrations for three different fuels: 100 octane (105 RON), 93 octane (98 RON), and 91 octane (95 RON). Higher octane ratings indicate higher quality fuel that burns more slowly and can support higher cylinder pressure. This difference in fuel will determine how the car is tuned. 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 can result in damage to the motor.

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

The Macan utilizes a calculated mass airflow, but does not use actual MAF (Mass Air Flow) sensors. It uses airflow calculations to estimate engine mass air flow. The Macan uses airflow calculations to limit boost pressure, so making changes to calculated airflow tables is critical to making the car run correctly.

Step 4 – Calibration refinement on a chassis dynamometer.

A: Perform initial testing at low boost.

After selecting the most appropriate initial calibration, prepare to test and refine the calibration on a chassis dynamometer. When creating a custom tune, it is best to begin testing under low load conditions by lowering the boost. You will also want to lower the Pressure Up Throttle Setpoint table.  This is the target boost pressure based off of airflow in mg/stk.  Airflow (mg/stk) can be monitored by watching Predicted Air Mass.  

B: Connect the Accesstuner software to the Accessport equipped Macan

Open the selected starting calibration in the Accesstuner software then configure the Accesstuner software to connect to your vehicle. Attach the OBDII connector to the vehicle and, to your Accessport (if applicable), then connect the associated USB cable to your computer. Press "Ctrl+F" to configure the program. Select the directory in which to store your data logs under the "Logging" tab.

C: Log critical engine parameters while testing.

Accesstuner software allows the user to sample and record critical engine parameters including sensor information and commanded engine function. Open Accesstuner and load the calibration currently flashed to the vehicle. Attach the OBDII cable to the vehicle and the computer. Press "Ctrl+F" to configure the logged parameters in the "Log List" tab, and those displayed in the Accesstuner "Dashboard" through the "Gauge List" tab. The Dashboard, a screen that reports active engine and sensor parameters, can be accessed by pressing "Ctrl+B." It is critical to actively monitor the condition of the motor during tuning and this screen is the single best way to do so. These data monitors allow the tuner to determine if a calibration is performing correctly. Accurate and deliberate assessment of logged parameters is the only way to avoid conditions that may damage the motor.

The Macan Accessport can log 25+ parameters around 40 Hz, The amount of parameters selected has a negligible impact the logging speed.

D: Tuning for appropriate Air to Fuel Ratios (Lambda)

The ideal air to fuel ratio (AFR) depends upon fuel quality, engine design, fueling model (port injection, direct injection, diesel, etc.), heat exchanging abilities, and other variables. Higher octane fuels are more stable at higher cylinder pressures, and are more resistant to knock. Leaner AFRs can produce higher power, but generally also create more heat that may lead to unsafe pre-ignition. Lower octane fuels, such as 91(95 RON) and ACN91 (Arizona, California and Nevada 91 octane), are less resistant to knock and require a richer (fewer parts air per parts fuel) AFR for safer operation. Richer AFRs produces less heat, protect against detonation due to a cooling effect of the excess fuel and usually produce less power. We have found that the Macan motor is tuned on the leaner side from Porsche. After some initial testing we have found that just by richening the fuel target, the car picked up power. So we suggest a target AFR of 11.8:1 or a Lambda of around .80.  There is some significant cam overlap during spool up on the Macan which will give a false AFR to the sensors.  It is not uncommon to see a reported AFR around 16:1 during spool up.  

Air to fuel ratios for these vehicles are directly impacted by several tables. The Porsche fuel control system operates a closed loop control strategy. This means that the car runs a set of wideband air fuel sensors, and is constantly adjusting the fuel targets based on a collection of variables. The fuel target under wide open throttle is dictated by the Lambda Full Load Enrichment, Lambda Full Load Enrichment, and Lambda Full Load Enrichment for Sport Mode tables. Setting a target in these tables will yield the desired Air Fuel desired.

A fuel mixture that is too lean will contribute to uncontrolled combustion, excessive heat, detonation and possible engine damage. The objective is to run the car at the richest air to fuel mixture possible that does not sacrifice power. Ultimately, the best air to fuel can only be determined in concert with changes to ignition timing. For example, in some cases a comparatively rich air to fuel mixture can be run with more ignition timing than a leaner mixture. This combination may produce higher power than a lean mixture with less ignition timing. Generally speaking, the air to fuel and ignition timing combination that produces the best power while minimizing heat is the desired calibration. Of course, this ideal is not limited to ignition timing and fuel, but is also a balance of variable cam timing and boost pressure.

E: Tuning Ignition Timing

The ignition control strategy in the Porsche Macan is very dynamic and has a lot of contributing variables to determine the overall ignition timing value. Since the car is always trying best to calculate an overall best efficiency, it does this for ignition timing by using the Absolute Calibration for Reference Ignition Angle Due to Valve Overlap and using a target lambda (ʎ) =1 as a base for the efficiency. Additive corrections get made and it forms a variable in the ECU that is "optimal timing." This is the basis for all the ignition calculations in the car. The Porsche uses a strategy of two states of cam timing as well. These points will dictate which of the ignition timing maps are used and when. The actual ignition timing uses some additional variables and then comes to the conclusion of ignition timing based on the difference between Absolute Calibration for Reference Ignition Angle Due to Valve Overlap and Calibration for Reference Ignition Angle Due to Valve Overlap. Ignition Timing changes will need to be made in the Calibration for Reference Ignition Angle Due to Valve Overlap tables to start, as these are the basic tables that will reflect changes made. 

In some cases the ECU may revert to the Basic Minimum Ignition Angle tables.  This is more common on the Macan Turbo when raising boost pressure.  In this case you can use these minimum ignition tables to modify timing.  These tables are not absolute minimums and if there are knock corrections the ecu can and will still pull timing down below what these tables dictate.  

F: Knock Control System

The knock control strategy on the Porsche Macan is very complicated and uses individual cylinder knock control to make changes to the ignition timing at all times. The system is very sensitive and thus almost always has some sort of feedback, particularly during cruise and light throttle inputs. You can monitor knock retard and ignition correction in each cylinder. This is the best way to check for detonation, and to ensure a safe running vehicle. The closer to 0 the better, but if it sways into the negatives (-1 and below) this is the car registering knock. Since the car is very dynamic it is made to be sensitive. If you are getting values past -6 under WOT you will want to try and lower ignition timing, or add more fuel to try and see if you can bring the values back closer to 0. Running a race fuel will also help in getting the knock control values closer to zero.

If running built engines you can change the knock detection thresholds in the software. By raising these tables you are de-sensitizing the knock control system. THIS SHOULD BE DONE WITH GREAT CARE AS DOING THIS CAN RESULT IN ENGINE DAMAGE AS KNOCK CONTROL BECOMES LESS ACTIVE!!

Generally speaking, higher ignition timing supports higher torque and greater power. However, ignition timing should be increased with great caution. Higher timing yields are limited by fuel quality and the mechanical limitations of the motor due to higher cylinder pressure. Too much timing will produce knock sums when fuel quality is the limiting factor. When fuel quality is high, ignition timing should ONLY be added when its addition produces a substantive increase in torque and power. If increased timing does not increase torque, the extra cylinder pressure is simply producing unnecessary stress on engine components.

G: Porsche Torque & Boost Control Strategy

The Porsche Macan uses torque control and airflow targets to influence how the car behaves on power and off power. This system uses input from a wide variety of internal variables and external sensors to dictate how the car reacts in certain conditions. The boost control system works in this same manner, not by trying to use a "standard" boost control setup, but by trying to achieve target torque and airflow values. This is dynamic and varies based on engine conditions, temperatures, etc... 
This ECU uses various methods to control torque output, such as closing the throttle plate when the car overshoots a target torque or airflow maximum table. So you will always want to monitor throttle plate opening as it is a way for the car to lower the torque output. Other methods include lowering ignition timing, or changing air fuel ratios. So you want to be sure that the car is optimally calibrated in all conditions.  Throttle closures are not always bad and they may be used to regulate a target airflow you have set.  If you are achieving your target airflow but are still getting throttle closures it is recommended to decrease your boost target.   

This control rhetoric is implemented by the ECU and changes boost pressure to meet the torque and airflow targets set in the tables. There are also some wastegate tables that will directly affect the boost pressure control such as Open Loop Wastegate Table (Feed Forward Control) #1-#4.

The ECU uses a pressure target system for boost control as well to try and control boost before the throttle plate. This table is called Pressure Up Throttle Setpoint.  The Mass Airflow Setpoint Limit Tables will also need to be raised when raising boost.  If Predicted Air Mass surpasses these limits the ecu will take steps to lower air mass by either closing the throttle or lowering boost.    

H: Tuning Variable Cam Timing (Vario-Cam Plus)

Porsche uses a variable cam timing system that changes cam duration at different engine speeds, but with Vario-Cam it also changes the valve lift dependent on cam phasing. This provides very good efficiency in all driving ranges as it can change lift using hydraulic tappets with a type of attachment pin. There are 3 lobes on the cam and the center is the "slow lift" the outer 2 lobes are the fast lift and pertain more to making more power and a higher lift. This helps to make more power through the power band.

The cam timing can be changed in the software. In order to see results from this type of tuning a chassis or engine dynamometer is required.

I: Speed Density/ Estimated Mass Flow

The Porsche Macan does not use MAF sensors, but instead uses calculated airflow using variables calculated from sensors and other parameters in the ECU. It then uses these types of calculations to estimate the amount of airflow entering the motor based on the engine displacement and a slew of other variables related to air flow, temperature, and barometric pressure. It does calculate a volumetric efficiency slope and offset. So while the ECU does not use a traditional speed density strategy, it uses a type of pseudo MAF/ SD setup using calculated variables and measured airflow into the motor through the PUT sensor and the MAP sensor.

The ECU also uses heavy torque targeting methods. Most of the boost control is done by trying to achieve a target torque value and a mass flow that is calculated by the ECU. This target is very important, and being too far over or under can cause the car to have errors. 

J: Integrating all tuning parameters for the ideal calibration

The ideal calibration for your Porsche Macan is a combination of all major tuning areas outlined above. Generally speaking, the Porsche Macan will make the most power when it runs a lean AFR with the maximum amount of ignition timing allowed by the ECU without knock. However, the theoretical ideal air to fuel ratio and high ignition timing is not realistic for all configurations and fuels. Calibrations should be thoroughly tested on a chassis dynamometer, where the impact of tuning is easily measured, to determine if they are ideal for the vehicle, its mechanical components, and its fuel. For example, addition of ignition timing that does not result in increased torque is not ideal because it produces additional stress on engine components without a perceivable benefit. The same is true of boost and air to fuel ratio. If the vehicle can operate at a richer air to fuel ratio without losing power, it is ideal to do so. If increasing boost does not yield considerable power gain, the turbo may simply be out of its efficiency range and, in this scenario, less boost is actually more power. For a basic idea of ideal tuning parameters for your fuel type and mechanical configuration, examine the COBB OTS map notes.

K: Precautions:

Boost – The stock turbo chargers can produce boost levels in excess of 25 psi, which is enough cylinder pressure to cause engine damage if not tuned correctly. Be cautious when adjusting boost control parameters, particularly when any mechanical components of the boost control system have been altered from the factory configuration.  

Fuel – The stock fuel system in the Macan is Direct Injection. Therefore the fuel is injected directly into the cylinder at very high fuel pressures to help atomize the fuel. There are limitations to these systems, so you will want to measure fuel pressure to see if you are having any issues with fuel delivery.

Toggles (Base)

Torque Strategy Change

Toggle Description- When this toggle is checked the ECU will bypass the torque control strategy and use the Pressure Up Throttle Setpoint and Mass Airflow Setpoint Limit tables to regulate boost and regulate max torque based on airflow.  

Tuning Tips- We recommend tuning with this toggle checked to simplify the tuning process.  There can be alternate ways to tune the Macan airflow/torque/boost models without checking this toggle however it can be much more intricate. 

Precautions and Warnings – If the Macan goes into limp mode with this toggle checked it may not throw a CEL code when scanned.