Lean Fueling during Transient Throttle (Direct Injection)

I believe I am experiencing timing corrections due to lean fuel conditions during transient throttle on my BMW B58.

I may be wrong but there doesn't seem to be any transient fueling tables that I can change using the BootMod3 (BM3) software. If there aren't any transient tables then what else can be done to minimize the lean condition and thereby reduce timing corrections?

I attach a log for reference: bootmod3 datalog - Stage 1 91 octane

Any help would be greatly appreciated

DI engines don't have the transient fueling needs of port injection, so usually what you're seeing is the result of passing through areas where fuel/airflow mapping needs adjustment. That adjustment can be done at steady state on a load bearing dyno, or there are some suggestions on doing this without one in the road tuning course.

Thanks again Mike!

The problem that I am finding with my application is that there isn't currently a direct example in the course material.

It seems the BMW ECU uses both the MAF and MAP to calculate load. I have the tables below available in my reflash software but I'm not 100% sure on what the tables are and therefore reluctant to makes changes with gaining some further knowledge.

Shaun thanks for that info. While I haven't tuned the exact system you're working with, combined MAF MAP operation is used in many systems and I can tell you how I generally approach it.

If possible to operate MAF only, then SD only, I may tune each system one at a time, confirm they're calculating similar airmass in similar conditions, then run with both enabled to finish the tune.

Sometimes you can alter the conditions under which one system or the other is used. For example don't use MAF under or over x airflow, voltage or frequency. Or perhaps don't use MAP under or over a certain MAP delta.

If you can't disable one of the two calculations from having an impact on airflow calculation in that way, sometimes you can do it by causing a temporary failure of one system at a time by unplugging a sensor, or causing them to operate over/under a DTC limit. With this approach though, SOME control systems will go into more of a fail state with alternate behavior that's not desirable and prevents this method from being helpful.

Technically you can leave both systems active and adjust both at the same time, if you can log the airmass each system is calculating independently, and see which system is currently being used (sometimes by weight/%). This can make things a bit more complicated, but it is an option. If you can't log which system is active though, you'll just be guessing, so you're better off with the one at a time method.

Out of the tables you pictured, the Range Check values look like they may allow you to avoid using one system. If the ceiling and floor are both 0, that system likely won't be used.