Some of the TDi engines can read higher than 2550, but the maps are still scaled up to 2550.

I don't know if this extends to other variants, including 1.8t.

It is very frustrating.  You shouldn't remove control of the boost from the ecu, it's a key function, yet it can't control it very well above 2550mbar

As already stated it would be quite a task to either rescale the scales for every map / constant so that there was a factor between the byte and the actual pressure.  Or even harder cast that byte to int16 throughout the code!

Aside from these two maps, there are also a number of maps that predict the change in load based on the change in intake pressures. That is the only other system I can think of that relies on pressure.

I am really against underscaling load. It is possible to make it work of course. But underscaling load has a number of side effects:
-Your data logs are all off and can't be directly compared to regular cars
-You have effectively disabled all of the high load protection systems in the car

If you are willing to rescale all of the maps in the car that deal with component protection to now enable protection at lower loads, then you can run with underscaled load and not have issues.

It may cause some problems with the ECU predicting the "slow path" load changes. I would think this would cause the ECU to undershoot or overshoot it's load control.

There are maps that convert manifold pressure into cylinder pressure and into turbo pressure. I assume those could be used to adjust the slow path calculations when using an underscaled MAP.

Here is some of the definitions of the relevant maps I have in my old map editor software.

There are addresses from the MBox 0002 bin file. "TwoDConsecutiveIntervalMap" means the map format is: height, width, height lookup table, width lookup table, height x width map table data.

TwoDConsecutiveIntervalMap("Correction Factor for going from intake pressure to cylinder pressure during max camshaft advance", 0x81BC16, UINT16, 1.0 / 32768.0, 0.0, "Factor", "", OneDimensionalMap(engineSpeedVar_UInt16_F87A), OneDimensionalMap(loadVar_UInt16_F990)));//10x10

TwoDConsecutiveIntervalMap("Correction Factor for going from intake pressure to cylinder pressure during min camshaft advance", 0x81BB22, UINT16, 1.0 / 32768.0, 0.0, "Factor", "", OneDimensionalMap(engineSpeedVar_UInt16_F87A), OneDimensionalMap(loadVar_UInt16_F990)));//10x10

TwoDConsecutiveIntervalMap("Conversion factor from pressure to load", 0x81BDA6, UINT16, 1.0 / 219545.6, 0.0, "Factor", "%/mbar", OneDimensionalMap(engineSpeedVar_UInt16_F87A), OneDimensionalMap(camshaftOverlapAngleVar_UInt16_3822E8)));

TwoDConsecutiveIntervalMap("Internal Exhaust Gas Partial Pressure", 0x81BD0A, UINT16, 1.0 / 25.6, 0.0, "Pressure", "mbar", OneDimensionalMap(camshaftOverlapAngleVar_UInt16_3822E8), OneDimensionalMap(engineSpeedVar_UInt16_F87A)));

From what I recall, they are used to predict the change in load based on the change in pressure. It is used by the "slow path" torque demand system to predict how the load will change. The "slow path" uses these maps to determine if it needs raise or lower the boost pressure to meet the desired load.

When I release my data logger, you will be able to log the variables showing the ECUs expected load change based on the pressure change.

As far as I can tell, these are all in my map packs already:


This appears to be KFPBRNW at 1BC42. Its axis data starts at 1BC1A, not 1BC16 though, unless I got something wrong

KFPBRK

KFURL

KFPRG

I looked at it a bit few nights ago and the only "Quick" way would be to run larger MAP sensor (400kpa) from european TDI car. It has the same plug and housing.

It will read underscaled naturally. The Maps Tony listed can be used to make the MAP work as well as couple others dealing with minimum ambient pressure (700mbar), conversion of boost into air mass KVLAD and possibly few others, forget which ones now but WinOLS definition pack has quite a few you can touch.

There interesting one is DSLGRAD "Gradient pressure sensor for charge pressure" with default value of 541.0 hpa (0.541 bar). This is nothing else than scaling for our default sensor, 1v=0.541 bar. If only we didn't have that silly 2559mbar limit we could very easily stick any sensor you wanted in there and easily scale it up.