I've created a wiki site for collecting BMW B58 tuning information. The site is hosted at https://b58.wiki.

The basic aim is to act as an 'FRM companion', in that the content hopefully has sufficient detail but in correct English, in a pedagogical order with difficult points highlighted, etc.

The content is freely available and operates on wikipedia-like principles for anybody wishing to contribute.

It currently has a small but growing set of articles, among which are
* An close look at BMW's MPPSK tune (m-perf power sound kit).
* A straightforward guide to creating a stage 1 tune.
* A fairly thorough introduction to turbocharger control.

Hopefully articles on fuelling and timing will be up in the near future.

Contributions are welcome, especially from people with different versions of the sw/engine (mine is a gen1 M140i). Also donations or offers of trade from anybody who has relevant BMW application_export files are welcome as I am currently working from the older 209a_074_020_001_export_application_export and burn a lot time tracking the correspondence with my car.

But otherwise, if you are looking to get a handle on B58 tuning then do visit the site: https://b58.wiki.

Cool, does the overall structure also relate to the B48 ? (IIRC they use the same ECU)

Sort of. The B48 is DME8.4 and B58 is DME8.6. I am not sure what the two minor versions would indicate in practice but there will be quite a bit of crossover.

On the other hand, the wiki articles intentionally drop much of the generality of the DME software, which might lead to statements that would be wrong in the context of the B48. For example, the DME is coded to allow one or two turbos with or without PID-based wastegate control, cylinder counts from 3 to 12, etc while the wiki articles start from the assumption that we know the B58 cylinder count, that it has one turbo, pid controlled, etc.

To help write the wiki -- and map from my out-of-date FR and the newer software on my car -- I developed an A2L graphing tool. This is pretty useful for working out software differences at a glance. If I get some time, I'll run over some a B48 a2l. In the meantime, approach the content with caution if you're making changes on your car.