Hi all..
someone can explain me this map of dl501 on ecm titanium?
1 question : what is the logi...
Great questions — these DL501 Gen2 maps are not immediately intuitive. Let me break them down.
Image 1 — "Limitatore incremento della coppia alla frizione durante l'accelerazione - Marcia 2,4,6"
(Clutch torque increase rate limiter during acceleration — Gears 2, 4, 6)
Address: 0x026580 — 6×4 map — Unit:
Nm/s
1. Logic behind this map:
This map limits
how fast (the rate) the TCU is allowed to increase clutch clamping torque during acceleration events on even gears (2, 4, 6). It's a protective/comfort function — it prevents the clutch pack from slamming full pressure instantly, which would cause harsh engagement or shock loads on the drivetrain.
All values are set to
10000 Nm/s, which is essentially "wide open" — meaning the rate limiter is effectively disabled. The TCU can ramp clutch torque as fast as it wants. This is typical of a performance/stage calibration.
2. Why Nm/s?
The unit
Nm/s here means "Newton-metres per second" — it's a
torque rate of change (torque derivative), not a static torque value. It defines the maximum allowed speed at which clutch torque can increase. Think of it as:
- Low value (e.g. 500 Nm/s) = slow, smooth clutch engagement
- High value (e.g. 10000 Nm/s) = near-instant clutch engagement
3. Why axes go from -100 to +100 and only up to 60%?
- Y-axis (RPM|% Acc): -100 to +100 — This is not RPM despite the label. It represents the accelerator pedal rate of change (or torque request gradient) in percentage. Negative values = driver lifting off the throttle, positive = pressing the throttle. The range covers full lift-off (-100) to full kick-down (+100).
- X-axis: 5, 20, 50, 60 — These are pedal position breakpoints (% accelerator). The map only goes to 60% because above ~60% pedal the TCU typically switches to a different control strategy (e.g., full torque / sport shift logic) where this particular rate limiter no longer applies, or a separate map takes over for higher pedal ranges.
Image 2 — "Limitatore di coppia massima #11"
Address: 0x02087E — 3×1 map — Unit:
Nm/s
Logic:
This is a
maximum torque rate limiter indexed by
steering angle (deg): 0°, 45°, 180°. The DL501 uses steering angle input to modulate torque delivery — during tight turns the TCU can limit torque ramp to prevent driveline wind-up or understeer in the Quattro system.
All values set to
5000 Nm/s — again, effectively wide open / disabled. Stock values would typically be lower at higher steering angles (e.g., 180°) to protect the center diff and reduce understeer during tight maneuvers.
Summary
- Both maps control how fast torque can change, not the torque itself
- Nm/s = torque ramp rate
- The calibration you're looking at has these limiters maxed out (performance tune)
- Stock files will show differentiated values — lower rates at partial throttle, higher steering angles, and during lift-off for comfort and drivetrain protection
If you want to understand the stock behavior, compare these maps against your ORI file (I can see you have "EM020WT_ORI" loaded as a tab). The difference will show you exactly what was changed.