Low RPM, low/high TP area concerns

[RomChip200]

I have philosophical concerns about the following areas: 1, 2, 3, 4 ,5

1) When are they solicited (which driving conditions) ?
2) What are the target AFR for each area ? Is an area supposed to be leaner than other ?

a) I reach area 1 when gently exercising throttle to start from a full stop
b) I reach area 2 when exercising throttle stronger to start from a full stop, trying to escape faster from the stop
c) Area 3 is probably used when Alpha/N increase is invoked
d) What is area 4 for ?
e) I reach area 5 in at a least 2 conditions: cranking up phase (when switching to the fuel map or when exercising the starter for a longer time than usually required) or when driving back, i.e. exercising more the clutch pedal than the throttle, hesitating, so RPM drop

For a) and b), I usually see some AFRs in the 12-13 range, or sometimes lower, quite rich, but I also have sometimes a drawback: engine is hesitating and RPM drops a bit.
I want to improve b) without this side-effect of back and forth.

Map_area.jpg

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[Matt]

1.
Section 1 will be during initial acceleration and low gear RPM cruise
Section 2 high load, low cruise. Would only normally use this area on high load and low RPM (starting boost. Will be in the area more on a smaller turbo, where larger turbos will raise RPM sooner). Also in here on deceleration
Section 5 heading towards stalling low load
Section 4 high TP as a result of turbo spinning whilst low RPM and stalling

2.
Section 1. Normally expect around 14.7:1
Section2. Normally we aim towards 11.5:1 transition when going into boost
Section 5/4 pull out fuel if turbo spinning and pulling through airflow whilst on decel
Otherwise high TP at low RPM will result in too much fuel

a + b match my conclusions
c yes this would seem to be the case
d. If you are here, your turbo is still spinning adding fuel and you are about to stall. This is why I added anti stall (TP limit on TPS) maps in FP1.1 (31P0H for Z32 EDM)
e. yes normally here on RPM drop is what I see in customer log files

Sounds like you are seeing what I see, which is unwanted load on deceleration (cluch out) maybe, resulting in higher than wanted TP load, which then then adds more fuel on decel

[RomChip200]

It is not at all on deceleration, it is acceleration when escaping from a full stop and I concentrate on 400-1200 rpm range.
You cannot reach these area on deceleration with MT, especially on speed, except if you put to neutral when driving, which is not normal driving conditions ! The same for decelerating till a point you stall ...
My statement is my RPM drops too much when exercising strongly the throttle to move from speed=0kmh and launch the car in the most efficient way, without any jolt.
Ideally you want RPM increasing smoothly and linearly 850 ...1200 ..2000 but in my case it's 850 ... 1200 ... 600 .. 400 .. 1000 ... 20000, so I play in the area 2 & 4. This is maybe fully normal behavior as you are putting load on the engine to start from stop, but I want to tune this area with the right inputs.

Except AlphaN/Increase, is there any additional enrichment table based on quick move of throttle !? Something I would not masterize at the moment ? A table that would to be corrected for 800cc injectors vs. oem 370cc ....

What about Sync Rate Factor ? Sync TPS Factor (the most probable one) ?

Code: Select all

CODE:A019 ; Throttle position contribution
CODE:A019
CODE:A019                     ldaa    throttle_filt         ; Low-pass filtered throttle position
CODE:A01C                     ldx     #acc_throttle_map ; DATA:F910 acc_throttle_map:   fcb  64, 64, 64, 64, 40, 22,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0 ; ...
CODE:A01F                     jsr     interp_16             ; X=table adress
CODE:A01F                                                   ; A=value to look up
CODE:A01F                                                   ;
CODE:A01F                                                   ; A=output value
CODE:A01F
CODE:A022                     staa    acc_throttle
CODE:A025                     beq     ct_45

What is sure is MT and AT have differences there for VG30DETT (VG30DE is another story):

Code: Select all

VG30DETT MT:
-2	-2	-1	-1	-1	-1	-2	-3	-4	6	17	17	17	17	17	17
-2	-2	-1	0	0	-1	-1	-1	22	22	22	22	22	22	22	22
0	-3	-9	-16	-26	-26	-26	-26	-26	0	0	0	0	0	0	0

VG30DETT AT:
-2	-2	-1	-1	-1	-1	-2	-3	-4	6	15	17	17	17	17	17
-2	-2	-1	0	0	-1	-1	-1	8	15	20	22	22	22	22	22
0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0

VG30DE MT:
3	3	2	2	1	0	26	26	26	26	26	26	26	26	26	26
3	3	2	2	1	0	26	26	26	26	26	26	26	26	26	26
3	3	2	2	1	0	0	0	0	0	0	0	0	0	0	0

VG30DE AT:
1	1	1	1	1	1	1	0	0	5	18	18	18	18	18	18
3	3	2	2	1	0	0	0	0	5	18	18	18	18	18	18
3	3	2	2	1	0	0	0	0	0	0	0	0	0	0	0

[Matt]

Ah yes that instanteous take off where the car 'bogs' for a moment. What do your logs show with injection time and AFRs vs RPM?

The async TPS tables are worth experimenting with. Alpha/N just uses the last column more for full throttle (high TPS) conditions