Settings Reference
All tuning algorithm parameters with defaults and explanations
Settings are accessible from the menu bar via Options → App Settings.
They are persisted automatically to
%LOCALAPPDATA%\DigiTune\GTS\app_settings.json.
Click Reset Settings at the bottom of the page to restore all values to
factory defaults. Settings are grouped into tabs — each section below maps to one of those
tabs.
General
| Setting | Default | Description |
|---|
| Automatically Check for Updates | On |
Check for a new version of DigiTune GTS on startup. You can also trigger a manual check from Help → Check for Updates. |
| Prompt About Unapplied Changes on Save | On |
When you save the map with adjusted values that haven't been written to the table yet, show a prompt asking whether to apply them first. |
| Disable Multi-threading (Crash Workaround) | Off |
Run all log loading and processing on the main thread. The UI will freeze during loads, but this avoids a class of crash seen on some Windows machines. Only enable if DigiTune crashes when loading a log file. |
| CSV Parser | Standard |
Which engine to use for reading CSV log files. Standard is the reliable default. Arrow is typically 2–3× faster on large logs but has been observed to crash on some machines. Switch to Arrow if you want faster log loading and aren't seeing crashes. |
Log Viewer
| Setting | Default | Description |
|---|
| Time Axis Display | HH:MM:SS since log start |
How the log viewer formats time. Elapsed seconds, HH:MM:SS since log start, or Wall clock (absolute time parsed from the log filename or file modification time). |
| Downsampling Mode | None |
How dense channels are reduced to screen pixels. None is lossless (slow on million-sample logs), min/max preserves spikes, mean smooths noise, subsample is fastest but can miss narrow spikes. |
| Hide Intermediate Time Axes | On |
When multiple subplots are stacked, hide the time axis on every subplot except the bottom-most one. Reclaims axis-row pixels so the plot areas are larger. |
| Subplot Gridlines | Both |
Which gridlines to draw on the overview and subplot stack: both, vertical only, horizontal only, or none. |
| Create JSON Sidecar for Markers | Off |
When enabled, markers placed on non-HDF5 logs are saved alongside the log as a <log>.markers.json file. HDF5 logs always persist markers inside the file itself. |
Data quality & validity
These settings control how DigiTune GTS scores each data point's quality. Only high-quality
(steady-state) data is used to calculate tuning corrections.
| Setting | Default | Units | Description |
|---|
| Max AFR | 18 | ratio |
AFR readings above this value are discarded as invalid (e.g. deceleration enleanment or sensor dropout). |
| Min AFR | 8 | ratio |
AFR readings below this value are discarded as invalid. |
| Steady State Data Quality Time | 1.5 | s |
Window over which throttle and MAP movement are assessed for quality scoring. Longer windows demand more sustained steadiness. |
| Steady State Data Validity Time | 1.0 | s |
Window used to determine whether a data point should be excluded entirely (as opposed to just penalised). Shorter than the quality time. |
| Steady State Max TPS Change | 5.0 | % |
Maximum TPS change within the quality window before quality starts to degrade. |
| Steady State Max TPS Rate | 40.0 | %/s |
Maximum TPS movement rate before quality starts to degrade. |
| Steady State Max Valid TPS Change | 40.0 | % |
TPS change above which the data point is excluded entirely regardless of quality. |
| Steady State Max Valid TPS Rate | 100.0 | %/s |
TPS rate above which the data point is excluded entirely. |
| Steady State Max MAP Change | 10.0 | kPa |
Maximum MAP change within the quality window before quality starts to degrade. |
| Steady State Max Valid MAP Change | 30.0 | kPa |
MAP change above which the data point is excluded entirely. |
| Steady State TPS Penalty Scale | 1.0 | quality/% |
How much quality degrades per percent of TPS movement above the threshold. |
| Steady State MAP Penalty Scale | 1.0 | quality/kPa |
How much quality degrades per kPa of MAP movement above the threshold. |
| Minimum Coolant Temperature | 60.0 | °C |
Below this CLT, data quality is reduced. Data from a cold engine is less representative of normal operation. |
| Startup Blanking Time | 30.0 | s |
Data collected within this time of engine start is ignored entirely. Post-start enrichment and sensor warm-up artefacts are excluded. |
Boost control tuning
| Setting | Default | Units | Description |
|---|
| Boost Control Minimum TPS | 80.0 | % |
Only data above this throttle position is used on the Boost page. Ensures only full-throttle runs are analysed. |
| Boost Control Full Throttle Req. Time | 1.0 | s |
The throttle must remain above the minimum TPS for this long before data is included. |
| Boost Control Response Rate | 1.0 | kPa/% |
Expected MAP change per unit of solenoid duty cycle. Used to estimate how much to change the duty to hit the boost target. Adjust to match your specific turbo and wastegate combination. |
| Boost Control Maximum Error | 30.0 | kPa |
Data points where achieved boost differs from target by more than this amount are excluded as outliers. |
| 100% Duty Boost Multiplier | 2.5 | × |
The ratio of boost expected at 100% duty vs 0% duty. Defines the shape of the duty-to-boost response curve used internally. |
Idle control tuning
| Setting | Default | Units | Description |
|---|
| Idle RPM Response Rate | 20.0 | RPM/% |
Expected RPM change per percent of idle duty cycle. Used to estimate corrections on the Idle page. |
| Idle Averaging Filter Time | 2.0 | s |
Time window used to smooth duty cycle readings before they are included in the analysis. |
| Idle Settling Time | 5.0 | s |
Time the idle controller must have been active before data is considered valid. Allows closed-loop control to stabilise before sampling. |
| Idle Req. Time for Valid | 5.0 | s |
Minimum consecutive stable idle time required before a data point is included. |
| Idle expected RPM variation | 3.0 | RPM |
Acceptable RPM jitter during a stable idle period. |
| Idle expected MAP variation | 3.0 | kPa |
Acceptable MAP jitter during a stable idle period. |
| Idle Allowed RPM error | 15.0 | RPM |
Maximum deviation from target idle RPM before a data point's quality is penalised. |
AutoTune algorithm
These are advanced parameters. The Smoothing and Fit Emphasis
sliders on the AutoTune page are the primary controls — adjust
these settings only if the sliders alone are insufficient.
| Setting | Default | Description |
|---|
| AutoTune Gradient Smoothness Factor | 20.0 |
Weight applied to the gradient smoothness penalty during optimisation. Higher values produce smoother tables by penalising large differences between adjacent cells more strongly. |
| AutoTune Shape Commonality Factor | 20.0 |
Weight applied to the shape consistency penalty. Higher values encourage the result to maintain a consistent load-shape across all RPM columns. |
| AutoTune Load Weighting Offset | 30.0 |
Bias applied to load-axis weighting. Higher values reduce the relative influence of low-load data points, giving more weight to mid-to-high load corrections. |
Log warnings
DigiTune GTS scans your logs for potential issues on load. These settings control the
thresholds used for each warning type.
| Setting | Default | Units | Description |
|---|
| Warn: Max Coolant Temp | 100.0 | °C | Coolant temperature above which an overheating warning is raised. |
| Warn: CLT Duration | 2.0 | s | Continuous duration above Max Coolant Temp required before the warning fires. |
| Warn: Max Battery Voltage | 16.0 | V | Battery voltage above this value triggers an overcharging warning. |
| Warn: Min Battery Voltage | 12.5 | V | Battery voltage below this value triggers an undercharging warning. |
| Warn: Battery Voltage Instability | 0.5 | V (std dev) | Standard deviation of battery voltage above which instability is flagged. |
| Warn: Undercharge Time Proportion | 0.02 | fraction | Proportion of total log time spent below Min Battery Voltage required to trigger the warning. Prevents false alarms from brief dips. |
| Warn: AFR Sensor Failure Threshold | 17.0 | ratio | AFR above this value at open throttle is treated as a sensor failure indicator. |
| Warn: AFR Sensor Failure Min TPS | 5.0 | % | Minimum TPS for the AFR sensor failure check to be active. |
| Warn: AFR Sensor Failure Duration | 3.0 | s | Continuous duration of high AFR at open throttle required before flagging a sensor issue. |
| Warn: Lost Sync Min RPM | 500.0 | RPM | Lost sync events are only reported if they occurred above this RPM. Events at low RPM (cranking) are ignored. |
| Warn: Knock Rev Limit Fallback | 7000.0 | RPM | Assumed hard-cut RPM used to suppress knock warnings near the limiter when the log has no rev-limit channel (MegaSquirt, ECUMaster, MaxxECU). |
Log comparison
| Setting | Default | Units | Description |
|---|
| Log Comparison Min Data Quality | 80.0 | quality score |
Only data points above this quality score are shown on the Log Comparison page. Reduces visual noise from transient data. |