Hi all, thought I'd introduce myself and see if I can draw on others' experience with porsche me7.8 dmes! I'm learning as I go and I've been poring over various threads on here and thought I'd share what I'm up to. I've a 996 4s with a tweaked engine (3.9, schrick cams, x51 intake, bigger tb, 997 injectors) and have been trying to get it running properly. I'm running larger 997 ev14 injectors (with tvub from 997 bin and krkte dialled in on WOT with a wideband) because the origs are going to be pushed flowrate wise with the power I'm running - my assumption is the spray pattern should be appropriate given same number of ports and usage on similar inlet and head in the 997.
Data logging has proved problematic, I'm just live recording parameters off piwis and reviewing offline but this isn't great, as it's an ST10 I'm not sure me7logger will work and when I've parsed a bin I've only received a handful of parameters back. I'm not sure what other people have used?
The car is largely running well, AFRs are good and I've validated on WOT against a sensor on the dyno as well as my plumbed in lc2. I've still some challenges and some things that I don't understand, such as:
-rich spikes/bogging on transients under 2k rpm. I've been monitoring AFRs and reducing KFBKAL improved it a bit, but I note that the 997 bin has the same values as the 996 and from threads on here it feels like this shouldn't be the answer and this is fudging it - the injectors should work without touching this if fuelling/tvub is dialled in properly. I think I've got (static) fuelling relatively well dialed in through KFLF, but LTFTs dont seem to be moving much - I'm not sure whether that's because I'm close or they're just not very sensitive or doing their thing as they should.
I've tweaked KFMSNWDK and KFWDKMSN based on interpolating from the smaller 68mm boxster tb and the 74mm 996 tb to estimate the larger ~83mm tb (it's used in 996 gt3, 997 x51, 997.2) but without a binary for one of these or good datalogging capabilities I'm not sure I have perfect values. I'm also not sure how these maps impact running and it doesn't feel like changes have any impact to the rich spike accel issue. If someone anyone knows appropriate values that would help me a great deal to know these maps are set correctly.
-WOT tuning - I've only been able to alter AFRs through injector pw correction maps and KFLF, nothing else seems to have an impact
-rev limit - it doesn't appear to follow any of the NMAX parameters, not sure why?
I've ordered some different EV14 injectors which are a bit closer to the original in terms of flowrate (213g vs 187g rather than 237g in the 997 injectors) in the hope that they will require fewer tweaks to run properly.
I've also been looking at whether I could just run a 3.8 997 me7.8.1 dme which could potentially give me a very close factory tune out of the box. I've got one here that I'm ready to start looking into, but it doesn't appear to handshake with my 9x6 immo box and I can't delete immo. I'll potentially somehow have to hook up a M5x5 immo box from a 997. I have found an immo emulator, but this isnt very elegant... or cheap. I've seen mention on here of being able to delete the immo through the WFS function, but haven't found any parameters that I think might work. I guess even after this there could be a number of ancillary CAN comms issues with other modules in the car.
Enough rambling, but any thoughts on any of the above and to help my limited understanding are greatly appreciated
Tim
