Settings — Simulation | The Undercut Wiki

The Simulation tab exposes ~80 RaceConfig fields as live sliders, organised by group. This is where you tune the race sim’s behaviour to your taste — every value here directly modifies how the on-track action plays out.

The settings are grouped into 13 categories with colour-coded headers. Use the group dropdown (“All” by default) to filter.

Groups overview

Group	Colour	What it tunes
All	grey	Everything
Overtake	green	Attempt rate, commit thresholds, success bonuses
Dirty Air	purple	Following penalty, tire degradation in dirty air
Tires	tan	Wear lifetime, optimal temp window, grip penalties
Mistakes	red	Base probability, threshold tiers, tire-temp factor
Engine	blue	Engine map effects, heat damage rate
Components	dark grey	Aero, suspension, brake scaling factors
Track	green	Rubber evolution rate, grip / wear / temp offsets
Pit Stops	brown	Service times, fuel flow, out-lap penalties
Stats	olive	Driver stat scaling factors
Stamina	teal	Drain rates, fatigue effects
Visual	purple	(Placeholder for visual tuning)
Launch	orange	Standing-start launch behaviour (reaction, bog, wheelspin)

Frequently tuned settings

These are the sliders most players touch first.

Overtake

overtake_attempt_base (default 0.0005) — base per-tick attempt probability. Bump to 0.001 for a more chaotic field; halve to 0.00025 for fewer overtakes.
aggressivity_spread (default 1.0) — multiplier on the AGG-derived attempt factor. 5× spread between AGG 1 and AGG 20.
opening_lap_overtake_boost (default 7.0) — first-lap chaos multiplier. Higher = more T1 incidents.

Tires

tire_lifetime (m) — distance before the wear cliff. Increase for more 1-stoppers; decrease for tire-shredder feel.
tire_optimal_low / tire_optimal_high (°C) — optimal temp window. Narrower window = harder to manage tires.
tire_wear_speed_malus — pace penalty per wear unit. Steeper makes the cliff bite harder.

Mistakes

mistake_base_prob (default 0.06) — base mistake probability at zone transitions. 0.12 → twice as many mistakes; 0.03 → cleaner racing.
mistake_threshold_small / mistake_threshold_medium — boundaries between Lockup / Spin / Crash tiers.

Engine

engine_heat_damage_rate (default 0.000005) — per-tick heat damage scalar. Quadruple it (0.00002) for “engines die every 2 races” feel.

Pit Stops

pit_service_base_time (default 1.5s) — fixed pit cost regardless of refuel/tire change duration.
pit_tire_change_time (default 5s) — tire swap baseline.
pit_fuel_flow_rate (default 12.0 kg/s) — refuel speed.
pit_out_lap_penalty (default 0.03) — out-lap pace penalty after a stop.

Stamina

stamina_proximity_range / stamina_proximity_bonus — how proximity to other cars accelerates stamina drain.

Launch

launch_reaction_min / launch_reaction_max — driver reaction time spread at lights-out.
launch_bog_chance / launch_spin_chance — probability of poor launches.
launch_quality_min / launch_quality_max — overall launch performance distribution.

Slider mechanics

Each slider has:

Label — the field name + display name
Track — drag the handle to a new value
Live numeric — current value displayed
Lo / Hi bounds — config-defined safety range
Group colour — left edge of the row coloured by group

Drag with mouse to change. Scroll wheel scrolls the panel.

Saving

Slider changes save to saves/config.db SQLite, scope = "race". Each key=value pair is stored.

On race start, the values from config.db override the compiled defaults. Restart NOT required — set_config_override re-applies live after each save.

Reset Simulation Defaults

The “Reset Defaults” button on this tab rebuilds the slider list from RaceConfig::default(). Any custom values are reverted; the saved DB entries are NOT deleted on reset — they’re rewritten on next save with the default values.

Tuning advice

For more realism

mistake_base_prob 0.06 (current) — already calibrated against real-F1 mistake rates
tire_lifetime adjust to match your preferred 1-stop/2-stop dominance
engine_heat_damage_rate 0.000005 (current) — engines last 10–15 GP

For more chaos

mistake_base_prob 0.12 (double) — every race has a Spin or two
opening_lap_overtake_boost 10.0 — T1 mayhem
aggressivity_spread 1.5 — AGG drivers go for everything

For closer racing

dirty_air_speed_penalty reduce → less following penalty → cars stay close
overtake_attempt_base increase → more attempts per second
back_off_speed_factor reduce → less train-formation behaviour

For pure-pace (qualifying-style)

mistake_base_prob 0.02 → near-zero mistakes
Disable side-by-side resolution by setting side_by_side_max_corners very high (5+)

File / DB inspection

If you want to see what’s stored:

sqlite3 saves/config.db
> SELECT key, value FROM config WHERE scope = 'race';

Each modified slider creates a row. Reset doesn’t delete them; it rewrites with defaults.

You can also edit race_config.txt directly (next to the binary) — values there merge with the DB on load.

Settings — Career — career-mode-specific sliders
Settings — Display — render settings
Settings — Audio — volume sliders