Probably a quick one for the top guys here, so apologies if I'm asking a silly question.
I'm looking at EGT enrichment on my 1.8t (BAM/AMK engine - ME7.5).
So the usual LAMBTS is disabled as standard (CWLAMBTS = 0) and so when TABGSS threshold is reached this is when enrichment occurs.
I've been looking here -
http://www.nefariousmotorsports.com/wiki/index.php/ATR_1.60_(Exhaust_Gas_Temperature_Control) - but I don't quite understand how this enrichment is achieved.
Is it simply controlled by the PI control mentioned (ATRPI2) down to a maximum enrichment of DLATRMN?
If so, how is DLATRMN used, for example, in my file it is -0.39967. Is this subtracted from 14.7 (lambda 1) or the current requested afr?
I'm not one of the
top guys, but I'll try to provide a (not so timely) response to this question.
The car in question is a 2.7 A6 with 4B0907551G ECU. I'm using a combination of LAMFA/KFLAMKRL/BTS fueling. BTS is mostly used for component protection at really high EGTs, right before ATR kicks in. Anyways, in normal conditions my req lambda shouldn't go much lower than ~0.78 at WOT.
During prolonged high gear runs I trip ATR sometimes - and it starts pouring raw fuel into cylinders to the point of making it so rich (I've seen request go as low as ~0.38!), that EGTs actually start climbing back! I guess that's because excessive fuel starts burning in the manifold. Check the pic.
EDIT: my BTS is not stock and is not
that rich, so it's not the cause. And the difference beween banks is up to ~0.4 - which suggests that DLATRMN is reached.
EDIT2: EGTs start climbing back because it's dumping fuel to the wrong bank. EGT sensor connectors were swapped between banks. Other points I made still stand, though. It goes WAY rich.
