N55e shift braps and looking for F chassis MPPK bins

fstbtstr

Private
Apr 14, 2024
43
38
0
Hey all, I am looking for some F chassis N55 MPPK bins, it doesn't look like any stock bins at https://github.com/dmacpro91/BMW-XDFs/tree/master/F series N55 S55 N13 are MPPK. Ideally, I'd really like to compare a non-MPPK and MPPK bin for the same DME "box code".
What I'm trying to do is to determine what is changed in calibration and possibly in the software itself to enable those infamous shift "braps", "farts" or "ignition cut" shifts as some call them.
I have already determined that these shift "farts" are the same thing as VW "dsg farts" and happen when fuel injection is momentarily switched off on several cylinders.
Moreover, I also have already managed to make my e90 335i to "fart" on some upshifts, although these are not too loud atm, especially with stock exhaust. At the moment, this is done kind of in a VW way, i.e., advancing the latest possible ignition angle (an analog of zwmin in VW's MED17s) to the point that required torque reduction only via ignition angle retardation is no longer possible and injection needs to be cut on one or more cylinders. I'm not 100% happy with this solution because looking at stock F series roms and data logs, it looks like ignition angle manipulation is a lot less direct and perhaps doesn't (just) happen on the "zwmin" level. Everything seems to be working good, but I'd prefer to hijack the existing OEM pathways instead of creating my own.
Btw, are there any good and cheap mics for recording exhaust sounds?
 
  • Like
Reactions: wheela

fstbtstr

Private
Apr 14, 2024
43
38
0
anyhow, I started looking into "dsg farts"/fuel injection cuts because you need to cut the injection in a clever way to have a nice smooth "antilag" rev limiter. Here's what I got now, first attempt is in D, second one is in P:
Here's an older video I posted back in May or June, this is not smooth enough for me and doesn't sound good:
Apologies for the "squirrels", I don't know what this is, this sound comes up when the engine is warmed up, I thought it was belt/pulleys but looks like it's not the case
 
  • Like
Reactions: wheela