Multimap on a M47 engine?

[Barryaster]

Hello everyone,

I am currently working on my 120d E87 project, and I am interested in installing a multimap system for the mentioned car.
The exact situation is as follows:

Current situation:
The car is running on a high Stage 3 spec. The problem is, that the car was originally build for drag racing.
Therefore, the current engine map is not suitable for trackday use, since the boost is way too high for that.

Objective situation:
I would like to use the car also on trackdays, but still have the "max-boost" map available. For this reason, what I need is a second map + system to switch between these two maps.


After doing a lot of research, it seems that there are no "pre-build" products for this purpose (such as the JB4 for the N54 engine).

In conclusion, it seems that I will need to build some kind of hybrid ECU between two ECUs. As far as I know, it seems that there is a part of the ECU (eprom? I think...) where the map-data is stored, and it seems that somehow, maybe connecting this part in parallel with a on-off switch??, it should be possible to achieve the multimap feature.


Could anyone give me a little more light with this topic?
I would really appreciate all kinds of help

Thank you very much in advance!!

[328 Power 04]

If your car and dde (EDC16 right?) has the option for sports mode button, you can just restrict the torque or IQ numbers in the maps for normal mode, and allow max for sports mode. It's not map switching, like you mention it, but it will work. I can do this for EDC17C50 N47 easily, but I have not done EDC16. Same idea though.


You know it has nothing to do with boost but rather fuel injection quantity, right?

[Barryaster]

Thanks for the quick response!

Yes, the car is running on a EDC16, but unfortunately the sport mode button feature is not available for this model.
My idea is to have a second map, since I would need to adjust everything, not only the boost.

I know there's people who have done the hybrid ECU between two ECUs, but I have no idea how it is exactly done nor which part of the ECU is where the map data is stored.

If I had this info to start with, I could try to do some self development and testing and see what happens.