bootmod3 Tuning Guide - MG1 PPC / Aurix
This page contains tuning guides designed to help users better understand how the bootmod3 map editor interacts with MG1 in PPC / Aurix-equipped BMW vehicles. The guides are meant for learning and reference, covering both basic MG1 concepts and more advanced hybrid tuning strategies, and are intended to support tuners and enthusiasts as they gain confidence reading logs, interpreting torque limits, and making safe adjustments
The main difference between the MG1 PPC and Aurix-equipped cars are related to more limiters, which in this case can be datalogged; this will be discussed in the load and torque table section. This Tuning Guide provides a general overview of the process. Values of the tables will vary depending on what car you are trying to tune, but the tables will be the same. Please note that Aurix will have more tables, and these will also be shown and pointed out as Aurix tables.
Engine Type | ECU Type | Displacement |
|---|---|---|
B48 Gen 1 | MG1 PPC | 2.0L |
B58 Gen 1 | MG1 PPC | 3.0L |
N63T2 | MG1 PPC | 4.4L |
B48 Gen 2 | MG1 Aurix | 2.0L |
B58 Gen 2 | MG1 Aurix | 3.0L |
S58 | MG1 Aurix | 3.0L |
N63T3 | MG1 Aurix | 4.4L |
S63T4 | MG1 Aurix | 4.4L |
The calibration in this Tuning Guide will be from a BMW Z4 M40i with the B58D engine to show the additional limiters that may be over the B58 Gen 1 engine.
Torque-based ECU:
The MG1 ECUs are torque-based, meaning these ECUs operate by a torque limiter/target that the ECU will try to reach. This is done by converting the torque target based on pedal input into a load target. The load target sets the boost pressure, fuel mass, and ignition timing to produce the requested torque.
MG1 Tables:
We will look at the following:
Load and Torque
Boost Control
Fuel
Ignition Timing
Load and Torque
These cars do not run a fixed boost target; they go by a torque target. This means, even if the ambient temperature drops or increases, the car will try to achieve this torque target, making the same power in any scenario. This will be done by increasing the boost or ignition timing.
In the Load and Torque section, the following sections will be covered:
Maximum Torque Limit
Optimal Reference Torque
Full Load Torque Limitation
Maximum Filling
Torque Monitors
Torque Reduction Factors
1. MAXIMUM TORQUE LIMIT
There can be up to 5 of these tables, depending on the ROM version. These are the global torque limiters and must be lifted over stock to make a higher power output. For starters, increase slowly, remember this is the maximum output possible in NM.
The torque from these tables is converted to load using the Optimal Reference Torque tables.
2. OPTIMAL REFERENCE TORQUE
The higher the torque output, the higher the load request. This results in a different ignition timing and fuel mixture since the values of those tables change based on load %.
To make the above the highest load value of the X-Axis, the table below(Optimal Reference Torque) must be scaled. The correct way of doing this is by increasing the 200% load value of the X-Axis and the respective column by the same percentage.
Depending on the car, B58 TCU has a limit of 550NM, S58 / N63T2 / N63T3, and S63T4 has it set to 760NM.
CustomROM has this torque limiter skipped, meaning there will be no limit from the TCU. Although transmission flashes are available for almost all vehicles today.
3. FULL LOAD TORQUE LIMITATION
There are several of these tables for different scenarios; these should be set high enough not to limit anything. These can be set to 800 or even 1000NM across, which will not hurt the drivability or performance of the car when going for such high values.
4. MAXIMUM FILLING
Maximum Relative Filling Characteristic
There are several load limiters and setpoints that have to be changed, depending on ROM version; some can have more, others less, but they are all available under Load (Relative Filling) -> Setpoint.
Maximum Relative Filling Characteristic
Relative Filling (Timing Retard)
Relative Filling (Timing Retard – Sport Mode)
Relative Filling Target (Component Protection)
Relative Filling Target (Launch Control)
Relative Filling (Fuel Quality)
Relative Filling (Fuel Quality – Sport)
On some ROM versions, you may find several of the above table set to 327%.
Maximum Filling Relative Filling Characteristic
The maximum load setpoints must be increased in order to achieve higher power levels. These are the main load limiters. These can be handy to limit boost pressure if keeping torque limiters high. Stock turbochargers cannot flow as upgraded turbos to redline, so tapering the load limiters to redline will lower the boost target, resulting in a lower boost deviation.
Relative Filling (Timing Retard) + Relative Filling (Timing Retard – Sport Mode)
This table is based on RPM and on the ignition timing target pulled. You can increase this table at low ignition correction, while leaving the rest stock. Make sure to increase or be limited by the stock values.
Relative Filling (Fuel Quality) & Relative Filling (Fuel Quality – Sport)
These next two load limiters are based on the table Filling Reduction (Intake Air Temp. and Octane):
The value from the above table is on the axis of the following two tables. If the intake temperature is high and the adaptation values set the fuel quality factor high, that will reduce the load significantly, increasing where load already is high to what the main load is the way to go.
5. TORQUE MONITORING
These cars have several monitors to prevent tuning from happening. If these are not changed and the car makes more power than stock, it may go into limp mode. On some cars, the table ‘Full Load Torque Characteristic (Monitoring) also must be increased. On this ROM, it’s set to 3276NM from the factory.
Another interesting table is the following one; this is basically an anti-tuning table as well. This should be maxed out to prevent any codes that might appear due to quicker acceleration.
Relative Filling Flags (Aurix ECU only)
On the new DME type, MG1 Aurix, the reason for a load limitation can be datalogged. If you are struggling with a load limitation eventhough all limits are higher than the datalogged RAM channel ‘Load Limit’.
Torque Limit (Flag)
This RAM channel can be logged as hex/decimal. Please check the comments below:
Boost Control
The following tables will be covered in the boost control section:
I-Factor Limit (Ceiling)
Boost Control Variable (PID) Floor
Boost Control Variable (PID) Ceiling
Boost Ceiling
Maximum Pressure Ratio
WGDC P-Gain (hPa)
WGDC D-Gain (kW)
WGDC I-Gain
Compressor Map With Required Compressor / Turbine Output [kW]
PID Adder Ceiling
Boost Setpoint Limitation
Target Boost Pressure Offset In Sport Mode
1. I-Factor Limit (Ceiling)
This table will limit the maximum-I gain added. If the base wastegate duty cycle (wgdc) is not enough to meet the boost target at high engine speed, this table can help.
2. PID Floor/Ceiling
These two tables adjust the amount of PID that should be added based on boost deviation. Going too high on this can cause a boost to over/undershoot based on your PID settings. Leaving these two tables stock at high deviation, for instance, at high engine speed, may result in a pressure too low plausibility code – 120308.
3. Boost Ceiling
On the N55 engine, this is set to 2500hPa ~ (22 psi relative pressure). The B58 comes with a 4-bar pre-throttle mapsensor, meaning you can run up to 4 bar absolute pressure before running out of resolution. Please note, the stock turbocharger of the B58 gen 1 cannot flow much at higher engine speed, but midrange it can easily produce an excess of 22 psi, which can produce high amounts of torque. The turbocharger of the B58 gen 2 flows better to redline, thus holding pressure.
4. Maximum Pressure Ratio
This is another boost limitation based on airflow and intake temperature. This should be increased in order to achieve higher boost pressure targets. Without this, you may taper boost pressure at high engine speed.
5. WGDC P-Gain (hPa)
This is one of the more advanced tables that takes time to perfect. By logging boost deviation and (RAM), Target Mass Flow will get you the exact z value for a given engine speed in this table. Should the car under- or overboost in a given area, this table can be adjusted in the respective area. Adjusting this table will add or subtract wgdc to the base wgdc.
6. WGDC D-Gain (kW)
The D-Share table is a table that needs some work in general. Usually, going half across helps. This table is based on the rate of change of boost deviation. Higher values prevent fast spool; it basically slows down the P-Gain, and of course, lower values may result in overboost as a result of faster spool. Make sure to log and see the effect of your change.
7. WGDC I-Gain
This table is a tricky one. Usually, stock values work very well, but in case you are not hitting the boost target, this table can add wastegate duty cycle. Going too high in values can lead to a wavy boost pressure curve. On the other hand, this table can also be reduced in case you have too high boost pressure in some areas of the RPM range.
8. Compressor Map With Required Compressor / Turbine Output [kW]
These cars do not go by a direct wastegate dutycycle base table; they have a Compressor map instead. This table has Turbine Mass Flow and Boost Setpoint as axes and turbine (kW) as z-values. Increasing the z-value will increase the WGDC base. The base WGDC is adjusted mainly by this table, as this table changes turbine power should be added. Logging the RAM channels: WGDC (Base), Turbine Power (Base), and the Distribution Factor will help a lot in adjusting the base WGDC. Having a high WGDC base will result in overboost, especially if the car is equipped with an aftermarket high-flow downpipe. The Wastegate Feed-Forward table uses the Distribution Factor and the Exhaust Gas Mass Flow to determine what the wastegate base value should be (z-value). By increasing the turbine (kW) in the compressor map table, there will be a change in the distribution factor. The distribution factor is the split between how much of the exhaust gas goes through the turbine and out through the wastegate valve. The lower the value of the distribution factor, the higher the amount of exhaust gas goes through the wastegate valve. The higher the value of the distribution factor, the higher the amount of exhaust gas that goes through the turbine, resulting in higher boost pressure.
9. PID Adder Ceiling
This table is a limitation of how much more wastegate duty cycle the PID gain can add over the wastegate duty cycle base. This is a global limiter for the PID gain. Going too high may result in overboost, while going too low can result in underboost. Stock is fine for most applications, upgrade turbo may have to increase much further to make up for the higher boost requested. This calibration has the values maxed out, but limited by the PID Integral limits.
10. Boost Setpoint Limitations
This table may have a drop in the boost setpoint. This is mostly due to lowering the boost setpoint at higher airflow; see this as another limiter for the boost setpoint. This should be raised to prevent any boost target limitation. This table is a very big limiter in terms of boost pressure. This will limit your boost setpoint (x-axis on the Compressor map table), causing your turbine (kW) to drop at higher target mass flow. This should be increased in order to achieve a higher boost pressure for the respective ‘Target mass flow’.
11. Target Boost Pressure Offset In Sport Mode
Pay attention to this table, it will increase your boost target in sport modes above what it’s calculated to. This table is already increased from the factory, and it’s done so your target is high while at low pedal input (only in sport mode). This is done to have a boost build-up in front of the throttle plate, making it a feature that gives less turbolag i.e., when on a track or during spirited driving. As soon as you step on the pedal, boost is there giving the driver an NA feeling without the turbolag. This is a great OEM feature when on the stock map, but tuned, it may hurt performance. The higher the value, the higher the boost target, but this does not increase the torque target, which may result in throttle closures as the requested boost is bigger than the requested boost by the torque target. Zeroing out may fix throttle closures caused by this table.
Fuel
In this section, the following tables will be covered:
Lambda Target (Bank 1/2)
Lambda Limit (Floor)
Lambda Target (at Superknock)
Minimum Lambda
Fuel Scalar
Correction Factor
1. Lambda Target (Bank 1/2)
There are 2 lambda (AFR) targets for this car, one for each bank. If you take a look at the stock values, you’ll see the axis is set very high in load, up to 180%. Stock, this car will never reach such a load. If you log the N55 stock tune on pumpgas, you will notice how the AFR is. It never goes super rich, so this table should be understood properly (when stock). This table is set up so that whenever or if the load should somehow go very high, AFR goes very rich to cool down the engine and prevent knock. Tuned, these cars like it a little lean if the pumpgas is good; if you’re on a lower octane fuel, it’s suggested to go a little richer to prevent knock. A lambda of 0.82 or lower for low quality pumpgas works. For better quality pumpgas, 0.84 is acceptable. Tuning on ethanol blends, it is possible to go even leaner due to the cooling effects of the ethanol, but also to keep the high-pressure fuel pump (HPFP) on these cars, especially if the given car has a stock HPFP.
2. Lambda Limit (Floor)
This is the absolute minimum lambda; you’d want to set this to match the richest point of your lambda target tables.
3. Lambda Target (at Superknock)
On this table, BMW set the lambda target very rich at the load target that this car may reach stock. Should it experience a misfire or even worse, superknock, it will make sure to inject way more fuel to keep everything cool and to prevent further knock. This table can be modified, but personally, I’d keep this map stock. If you keep having a rich AFR even though you set the previous tables leaner than these values, AND you have fresh spark plugs and ignition coils, you can match the values of this table with the ones from your lambda target.
4. Minimum Lambda
This table is a global limiter for the richest point of lambda; this does the same as the Lambda Floor, but the Lambda Floor is based on load and engine speed, while this is just a 1-value table. Set this to the richest point of your Lambda Target tables.
5. Fuel Scalar
Keeping this table stock on pumpgas is the way to go. In case your fuel has more ethanol than expected, you can modify it. The only way to figure out how to modify is logs! You’d want to keep an eye on the STFT (Short Term Fuel Trims). That will tell you how much fuel is added or subtracted; you want to be around 1 in STFT. If your fuel has ethanol and this map is unmodified, you will notice STFT go above 1, meaning you need to inject more fuel. Simply increase this table across in percentage. For E30 fuels, you want around 5% increase on the whole table, again, logs! Make sure to log and check the STFT at idle (low load and low engine speed) and do a pull from low engine speed to redline. Look at STFT, load and engine speed and increase where needed.
• Load Limitations Due To Fuelling
There are several tables that can trigger the relative filling (flag). In this case, it would be set to 4. This is most likely due to a limitation caused by the low-pressure fuel pump (LPFP) tables. If you see a drop in load limit/target while the flag is at 4, these tables should be looked at:
The first one would set a flat load limitation; this can be set to the same value as any other load limit table or just set max (327) to not limit anything.
The second table, on the other hand, can help with flag 4. Lowering this table by 50% or even setting it to zero will disable any load drop caused by it.
Please note that, on some software versions, e.g., in the G8X S58, this table can be a very high value; please adjust with caution, as this may trigger limp mode on those.
Another set of tables that may help on flag 4 is the following:
All values of 9200 can be set to 10000, which includes the single value table for max mode, so it matches the boost mode max value of 10000. Please note, this example is from a B58 Gen 2 Z4 M40i. These values may be slightly different depending on the car and the country code. But following this example will help.
6. Correction Factor
This table is more or less like the fuel scalar; you’d want to increase this by the same amount if running ethanol blends. The rule of thumb is to increase it by 5% if on E30 blends. Again, make sure to log and adjust properly.
Ignition Timing
In this section, the following tables will be covered:
Base Ignition Timing (Full Load – Warm)
Ignition Timing (Full Load – Spool)
Ignition Timing Correction (Factor – Full Load)
Ignition Correction (Full Load)
1. Base Ignition Timing (Full Load - Warm)
This table sets the ignition timing targets over load and engine speed. The values shown are before any correction. Depending on what octane the car runs on, ignition timing should be adjusted. Best is to reduce ignition at higher loads by 2 degrees over stock, to prevent ignition timing corrections and or knock while tuning. Once all that is set, this can be increased. The values in the stock table (M135 in this case) are higher than the regular 35i models, such as 335i or 435i. For a regular 93 octane (98RON) fuel, these targets fit very well, but datalogging is necessary to make sure it follows the path of the values set in this table.
2. Ignition Timing (Full Load - Spool)
When tuned, more boost is in play; this may cause ignition timing corrections or even knock during spool. The following table should be adjusted to prevent that. Looking at the OEM values, ignition timing drops quite a lot at high load. To be on the safe side, this can be reduced further by a couple of degrees. This may cause a drop in performance, so this should be logged and reviewed.
3. Ignition Timing Correction (Factor - Full Load) & Ignition Timing Correction (Full Load)
These two tables work together; the factor table is a factor of the big ignition correction table. For pumpgas applications, the stock values are fine, but when on ethanol blends, the ignition correction at higher intake temperatures can be lowered due to the cooling effect of ethanol.
This will reduce the Base Ignition Timing (Full Load – Warm) by the Ignition Timing Correction (Factor – Full Load) multiplied by the respective value of the following table Ignition Correction (Full Load):
Tuning example of an N55 M135 (please note that the MG1-equipped cars have more limiters as mentioned above):
The test car is RWD and has a ZF8 automatic transmission, so we will be in 5th gear on our DynoJet.
Octane used is 98RON (93 octane).
To make any additional power on this car, we want to increase the Maximum Torque Limitation. For starters, start with a small increase, datalog the car. 3rd gear pull from low engine speed to redline. If you are on a dyno, just go ahead and do a pass in the appropriate gear.
Baseline datalog: www.bootmod3.net/log?id=614b3b54d10b4355c2311cce
We start by increasing our ‘Maximum Torque Limit’ by 50NM across:
1st Revision:
Datalog: www.bootmod3.net/log?id=614c6615d10b4355c23121cf
This made no difference in power as we are limited by the two ‘Maximum Permissible Clutch Torque’, we will also increase those two tables by 50NM across by marking all the z-values and increment on the pop-up window by 50:
2nd Revision:
Datalog: www.bootmod3.net/log?id=614c6787d10b4355c23121d1
We went on and incremented the torque values by another 50NM to see the outcome:
3rd Revision:
Datalog: www.bootmod3.net/log?id=614c6925c090c67cf1149b18
Comparing this datalog to the second revision, there is no difference at all in power. We are now limited by load.
Next will be to increase the ‘Maximum Filling (Ignition Retard)’ table.
Again, using the increment function, we marked the last 2 rows and increased the load limitation by 15.
4th Revision:
Datalog: www.bootmod3.net/log?id=614c6ac2ae729b7f195afefb
Great increase over the whole powerband, but still limited. To prevent the car from being limited by load, we will, in the next revision, set the table to 180 across in the last 2 rows:
5th Revision:
Datalog: www.bootmod3.net/log?id=614c6c4ec090c67c64a99e0f
Looking at the 5th revision datalog, I notice we are still limited, and there was no power gain compared to the previous revision. A quick glance at the datalog shows that we are limited by the pressure ratio.
Next will be to look at the ‘Maximum Pressure Ratio’ table to overcome this boost limitation. We increase the whole table using the ‘multiply by value’ function. We increase the whole table by 15%:
6th Revision:
Datalog (6th Revision): www.bootmod3.net/log?id=614c6e28c090c67cf1149b2d
Looking at the 6th revision, it is noticeable that the boost setpoint is increased in the higher RPM range. Boost target and actual boost are higher than the previous revision, which results in more power towards the redline.
Increasing the ‘Maximum Pressure Ratio’ table by another 15% to see if we are still limited by boost setlimit:
The dyno graph is more or less the same without a change, but when looking at the datalog, it appears that our boost target seems higher than actual, with a deviation of 2-2.5 psi in the high RPM range.
Moreover, going forward, we will have the Maximum Pressure Ratio set to 2.4 across, to prevent any high boost pressure while testing.
7th Revision:
Datalog (7th Revision): www.bootmod3.net/log?id=614c9500ae729b7f195affc0
To bring the actual boost pressure closer to the target, we have to play around with boost control. This may be limited by ‘Boost Setpoint Limitation’, which is based on airflow.
This basically allows for a big taper in boost setpoint to happen when airflow is high. We will set this to 3 across to prevent any limitation in boost pressure caused by this table.
To allow more PID to be added, the following tables were also changed:
8th Revision:
Datalog (8th Revision): www.bootmod3.net/log?id=614d9973c090c67cf1149fe2
No difference between the two revisions. Looking at the 8th revision datalog, it appears that our torque target tapers too much.
For the next revision, ‘Maximum Torque Limit’ and ‘Maximum Permissible Clutch Torque’ are set to 570NM across to prevent any torque limitation.
9th Revision:
Datalog (9th Revision): www.bootmod3.net/log?id=614d9a58c090c67c64a9a312
Great power increase on the topend after the torque limitation is set high. There still seems to be a limitation in the topend which points to the following table:
The OEM values clearly show a drop, causing our load target to drop.
For the next revision, we try to set the values from 4750RPM to redline to 0.086:
10th Revision:
Datalog (10th Revision): www.bootmod3.net/log?id=614d9ea1c090c67cf1149ffa
The 10th revision clearly makes more power up top by the change to the ‘Relative Filling Factor’. It seems to have removed the torque target limitation near as well on the top end.
Taking another glance at the datalog shows rich AFR near redline. This is because we are now hitting higher load targets since the last revision. Looking at the Lambda Targets (Bank 1/2), it is noticeable that the lambda target is set rich, stock this car never gets to those values and runs an AFR of around 12.4 near redline.
For this car, we set the lambda to 0.83 ~ 12.2 AFR:
Moreover, the boost was tapering from the target, causing a boost deviation. To prevent this, we datalogged the current map again and added the following RAM channels:
New datalog: bootmod3 datalog - Tuning Guide Map N55 EWG (10th Revision Run 2)
This time, we see that the Turbine Power (Compressor Map) caps around 30kW (z-value) and MAF Pre Turbine at around 50 lb/min (1360kg/h – Y-axis) and Boost Setpoint at 2.3-2.4 (X-axis). The stock turbine table seems to be capped at around 1250kg/h on the Y-axis. Using the ‘+ by %’ function, we increase the last value on the Y-axis by 20% and the Z-values in the last row of the Z-values by 25%:
11th Revision:
Datalog (Revision 11th): bootmod3 datalog - Tuning Guide Map N55 EWG (11th Revision)
The last and final revision results in slightly more top-end, approx. 12-13 whp more just before redline. Turbine Power (Compressor Map) has an increase in the datalog by 3kW, and our AFR seems to follow our target at around 12.1-12.2.
Baseline and the Final revision: