# ev_rotary_2_on Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 4200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4200 and crossfades it with the other bands and load takes.

# ev_four_3_on Seamless one-second loop of the `four` engine voice (Four-cylinder) at 6000 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 6000 and crossfades it with the other bands and load takes.

# ev_kart_1_on Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 2400 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2400 and crossfades it with the other bands and load takes.

# ev_turbo_2_off Seamless one-second loop of the `turbo` engine voice (Turbo four) at 3000 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3000 and crossfades it with the other bands and load takes.

# ev_v12_3_off Seamless one-second loop of the `v12` engine voice (V12) at 8400 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 8400 and crossfades it with the other bands and load takes.

# ev_blowoff A turbo blow-off valve: a sharp pressurised hiss as the throttle lifts at boost. engineVoices plays it on the turbo and diesel voices when the throttle closes with boost up.

# ev_pop_2 Exhaust overrun pop/crackle one-shot, take 2 of 3. `EngineVoice` fires these at random when a v8, rotary or turbo voice lifts off the throttle at high rpm, and on the rev limiter.

# ev_crash_light A light car knock: a dull bump and a short scrape of bodywork. engineVoices plays it on low-speed impacts (car.impactSpeed under ~7 m/s).

# ev_four_1_on Seamless one-second loop of the `four` engine voice (Four-cylinder) at 1080 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1080 and crossfades it with the other bands and load takes.

# ev_electric_3_on Seamless one-second loop of the `electric` engine voice (Electric motor) at 12000 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 12000 and crossfades it with the other bands and load takes.

# ev_skid_gravel Seamless loop of tyres sliding on loose gravel: crunching stones and scrub. Cut from the generated `ev_skid_gravel_src` take with an equal-power crossfaded wrap. Used on gravel and dirt.

# ev_crash_medium A medium car crash: a solid metallic thump with crunching panels. engineVoices plays it on mid-speed impacts.

# ev_rotary_3_on Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 8400 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 8400 and crossfades it with the other bands and load takes.

# ev_electric_2_off Seamless one-second loop of the `electric` engine voice (Electric motor) at 4800 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4800 and crossfades it with the other bands and load takes.

# ev_diesel_1_on Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 840 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 840 and crossfades it with the other bands and load takes.

# ev_diesel_2_on Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 2160 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2160 and crossfades it with the other bands and load takes.

# ev_skid_soft Seamless loop of tyres sliding on soft ground (grass, mud, sand, snow): a muffled scrub. Cut from the generated `ev_skid_soft_src` take with an equal-power crossfaded wrap.

# ev_rotary_1_on Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 1200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_electric_1_off Seamless one-second loop of the `electric` engine voice (Electric motor) at 1200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_v12_1_off Seamless one-second loop of the `v12` engine voice (V12) at 1200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_four_2_off Seamless one-second loop of the `four` engine voice (Four-cylinder) at 3000 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3000 and crossfades it with the other bands and load takes.

# ev_pop_3 Exhaust overrun pop/crackle one-shot, take 3 of 3. `EngineVoice` fires these at random when a v8, rotary or turbo voice lifts off the throttle at high rpm, and on the rev limiter.

# ev_v8_2_off Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 2520 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2520 and crossfades it with the other bands and load takes.

# ev_electric_1_on Seamless one-second loop of the `electric` engine voice (Electric motor) at 1200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_four_2_on Seamless one-second loop of the `four` engine voice (Four-cylinder) at 3000 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3000 and crossfades it with the other bands and load takes.

# ev_v8_1_on Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 840 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 840 and crossfades it with the other bands and load takes.

# ev_v12_1_on Seamless one-second loop of the `v12` engine voice (V12) at 1200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_rotary_3_off Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 8400 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 8400 and crossfades it with the other bands and load takes.

# ev_kart_2_off Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 7200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 7200 and crossfades it with the other bands and load takes.

# ev_diesel_3_on Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 3720 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3720 and crossfades it with the other bands and load takes.

# ev_inverter Seamless one-second electric-motor inverter whine loop (1.8 kHz switching tone with sidebands and hiss). Played under the `electric` voice, louder on load.

# ev_v8_1_off Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 840 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 840 and crossfades it with the other bands and load takes.

# ev_shift_seq Gear change one-shot for a sequential dog box: the ignition-cut bang in the exhaust and a hard dog-ring clack.

# ev_rotary_2_off Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 4200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4200 and crossfades it with the other bands and load takes.

# ev_kart_3_off Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 13200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 13200 and crossfades it with the other bands and load takes.

# ev_v8_2_on Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 2520 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2520 and crossfades it with the other bands and load takes.

# ev_v12_2_on Seamless one-second loop of the `v12` engine voice (V12) at 4200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4200 and crossfades it with the other bands and load takes.

# ev_four_1_off Seamless one-second loop of the `four` engine voice (Four-cylinder) at 1080 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1080 and crossfades it with the other bands and load takes.

# ev_kart_3_on Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 13200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 13200 and crossfades it with the other bands and load takes.

# ev_v8_3_on Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 5040 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 5040 and crossfades it with the other bands and load takes.

# ev_electric_2_on Seamless one-second loop of the `electric` engine voice (Electric motor) at 4800 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4800 and crossfades it with the other bands and load takes.

# ev_v8_3_off Seamless one-second loop of the `v8` engine voice (Cross-plane V8) at 5040 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 5040 and crossfades it with the other bands and load takes.

# EngineVoice The sound of a car. Put it on a car's chassis entity, the one that carries the driving contract's `car.*` named values, and it plays the engine, gear changes, rev limiter, turbo, tyre skids and crashes from those values. It needs no sibling component: any entity that writes `car.rpm`, `car.load` and the rest gets a voice, a `torqueCars` car, another car kit, or the `EngineVoiceDemo` stand-in. It spawns local child entities, each with a spatial `Audio` source at `doppler = 1`, so passing cars drop in pitch: - six engine layers, three rpm bands times on-load and off-load. They crossfade by rpm (equal power, in log rpm) and by `car.load`, and each is pitched to `rpm / band reference rpm`; - an aux layer: the turbo whistle that follows `car.boost` (turbo, diesel) or the inverter whine (electric); - a skid loop whose volume follows `car.skid` and whose clip changes with `car.surfaceId`: tarmac squeal, gravel crunch, soft scrub; - a one-shot host for gear changes (`car.shiftCount`), overrun pops, blow-off on lift, limiter stutter pops and crash crunches (`car.impactCount`, scaled by `car.impactSpeed`). The values replicate and the component runs on every peer, so every player hears every car. ## Fields | field | default | meaning | |---|---|---| | `voice` | `auto` | `auto` follows `car.voiceId`. Set a name to force a voice: `four`, `v8`, `v12`, `diesel`, `rotary`, `turbo`, `electric`, `kart`. It can be changed live. | | `volume` | 1 | multiplier for everything this car sounds | | `maxDistance` | 160 | metres to silence | | `shiftStyle` | `auto` | `auto` reads the `Car` component's gearbox mode, falling back to the voice's default; or `manual`, `sequential`, `automatic`, `none` | | `skids`, `crashes` | true | turn those sounds off | | `doppler` | 1 | Doppler scale on every source | `:mix()` returns what the voice is doing this frame: the voice, the smoothed rpm, load and boost, the band weights, the on-load and off-load gains, the level, the skid level and kind, and the ids of its sources. Read those ids with `audio.voice(id)`. ```lua car.component.add("EngineVoice") -- voice from car.voiceId car.component.get("EngineVoice").voice = "rotary" -- switch it live print(car.component.get("EngineVoice"):mix().bands[2]) ```

# ev_diesel_1_off Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 840 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 840 and crossfades it with the other bands and load takes.

# ev_skid_tarmac Seamless tyre squeal loop for paved surfaces (tarmac, concrete, cobbles, rumble strips, oil), from soundstage's generated `vehicles.skid` take 3. `EngineVoice` follows `car.skid` with its volume.

# ev_four_3_off Seamless one-second loop of the `four` engine voice (Four-cylinder) at 6000 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 6000 and crossfades it with the other bands and load takes.

# ev_turbo_3_off Seamless one-second loop of the `turbo` engine voice (Turbo four) at 6000 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 6000 and crossfades it with the other bands and load takes.

# ev_rotary_1_off Seamless one-second loop of the `rotary` engine voice (Twin-rotor rotary) at 1200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1200 and crossfades it with the other bands and load takes.

# ev_crash_heavy A heavy car crash: metal crumpling, glass and plastic breaking. engineVoices plays it, spatially, when a car hits something at high speed (car.impactSpeed above ~14 m/s).

# ev_shift_manual Gear change one-shot for an H-pattern manual gearbox: a two-stage metallic clunk of synchro and dog teeth.

# ev_electric_3_off Seamless one-second loop of the `electric` engine voice (Electric motor) at 12000 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 12000 and crossfades it with the other bands and load takes.

# ev_v12_2_off Seamless one-second loop of the `v12` engine voice (V12) at 4200 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 4200 and crossfades it with the other bands and load takes.

# ev_diesel_2_off Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 2160 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2160 and crossfades it with the other bands and load takes.

# ev_kart_2_on Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 7200 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 7200 and crossfades it with the other bands and load takes.

# ev_turbo_1_off Seamless one-second loop of the `turbo` engine voice (Turbo four) at 1080 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1080 and crossfades it with the other bands and load takes.

# ev_turbo_1_on Seamless one-second loop of the `turbo` engine voice (Turbo four) at 1080 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 1080 and crossfades it with the other bands and load takes.

# ev_turbo_3_on Seamless one-second loop of the `turbo` engine voice (Turbo four) at 6000 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 6000 and crossfades it with the other bands and load takes.

# ev_shift_auto Gear change one-shot for a torque-converter automatic: a soft driveline nudge.

# ev_pop_1 Exhaust overrun pop/crackle one-shot, take 1 of 3. `EngineVoice` fires these at random when a v8, rotary or turbo voice lifts off the throttle at high rpm, and on the rev limiter.

# ev_v12_3_on Seamless one-second loop of the `v12` engine voice (V12) at 8400 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 8400 and crossfades it with the other bands and load takes.

# ev_turbo_2_on Seamless one-second loop of the `turbo` engine voice (Turbo four) at 3000 rpm, on load (full throttle, harsh, more low harmonics). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3000 and crossfades it with the other bands and load takes.

# ev_whistle Seamless one-second turbocharger spool whistle loop (2.4 kHz turbine tone plus air). `EngineVoice` pitches it by `car.boost` and fades it in with boost and load, for the `turbo` and `diesel` voices.

# ev_kart_1_off Seamless one-second loop of the `kart` engine voice (Two-stroke kart) at 2400 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 2400 and crossfades it with the other bands and load takes.

# ev_diesel_3_off Seamless one-second loop of the `diesel` engine voice (Turbo diesel) at 3720 rpm, off load (coasting / overrun, quieter). Baked by `engineVoices.synth`; `EngineVoice` pitches it by rpm / 3720 and crossfades it with the other bands and load takes.

# engineVoices **engineVoices** gives cars their sound: eight engine voices that follow the revs from idle to limiter and how hard the engine is working, plus gear changes you can hear, a rev-limiter stutter, turbo spool and blow-off, overrun pops, tyre skids that change with the surface, and crash crunches. Every sound is spatial and Doppler-shifted, so a car passing you drops in pitch. The values that drive it replicate, so every player hears every car. It reads only the shared driving contract: the `car.*` named values on a car's chassis entity (`torqueCars` writes them, and so can any other car). Install it, put an `EngineVoice` on the chassis, and the car has a voice. ## Quick start Paste this into any script that runs in play, such as a scene's `entrypoint.luau`. It needs no car: a stand-in entity writes fake `car.*` values, running through idle, a full-throttle pull through the gears, the rev limiter, a lift with pops and blow-off, a slide and a crash, then moves on to the next voice. ```lua local started = false function update(dt) if started then return end local cam = layers.active.camera if not (cam and cam.ready and cam.entity) then return end -- wait for the play camera if audio.listener().count == 0 then cam.entity.component.add("AudioListener") -- the ears end local demo = entity.spawn("demoCar") demo.position = { 0, 1, -12 } demo.component.add("EngineVoiceDemo", { voice = "cycle" }) -- writes car.rpm, car.load, ... demo.component.add("EngineVoice") -- plays them started = true end ``` To hear all eight voices plus a fly-by in one line, use `require("engineVoices.showcase").start()`, or load the `EngineVoicesShowcase` scene in this package. On a real car, put the component on the chassis entity (the one with the car component, which writes the `car.*` values): ```lua local Voices = require("engineVoices.voices") Voices.attach(carChassis) -- voice from the car's car.voiceId Voices.attach(carChassis, "v12") -- or force one Voices.set(carChassis, "rotary") -- switch it live; "auto" goes back to car.voiceId ``` Or set it in the Inspector: `EngineVoice.voice` is one setting. ## The voices | id | name | what it is | |---|---|---| | 1 | `four` | Inline-four buzz: even 180° firing, raspy pipe | | 2 | `v8` | Cross-plane V8: uneven per-bank firing into two different pipes gives the burble, with a lumpy cam at idle and overrun pops | | 3 | `v12` | V12 scream: twelve overlapping pulses, smooth and high-order | | 4 | `diesel` | Turbo-diesel four: low thrum, combustion-knock clatter, turbo whistle | | 5 | `rotary` | Twin-rotor Wankel: needle-sharp pulses, brap-brap at idle, pops | | 6 | `turbo` | Turbo four: exhaust muffled by the turbine, intake whoosh, spool whistle, blow-off on lift, pops | | 7 | `electric` | Motor and gear-mesh whine rising with speed, inverter tone on load, no shift sound | | 8 | `kart` | Two-stroke single: nasal expansion-chamber ring, ring-ding four-stroking at low revs and on overrun | ## How it sounds the way it does - **Engine loops.** Each voice has six seamless one-second loops: three rpm bands, each with an on-load and an off-load take. All 48 were synthesized by `engineVoices.synth` from the engine's own firing pattern, using pressure pulses and combustion noise per cylinder firing, per-cylinder imbalance and jitter, exhaust-pipe resonances per bank, diesel knock, valvetrain ticks and misfires. A loop holds a whole number of engine cycles, so it has no seam. The spectral peak of every loop sits on the engine's firing frequency at the band's rpm, which `Synth.analyze` measures. - **Following the revs.** Each band loop is pitched to `rpm / band rpm` and the bands crossfade at equal power in log-rpm, so the note rises smoothly from idle to limiter without any loop being stretched far from where it was made. - **Following the load.** `car.load` crossfades the on-load take (louder, harsher, more low harmonics) with the off-load take (quieter overrun). Lifting at high rpm on a v8, rotary or turbo fires random exhaust pops. Lifting at boost on the turbo blows off. - **Gear changes.** When `car.shiftCount` changes it plays a manual clunk, a sequential cut-and-bang (with a short ignition cut on the engine layers), or a soft automatic nudge. The style is read from the `Car`'s gearbox, or set with `shiftStyle`. Electric makes no shift sound. The rpm drop itself is heard through the loops. - **Limiter.** While `car.limiter` is true, the on-load layer is chopped at about 16 Hz (the fuel cut), with crackle on the popping voices. - **Turbo.** The whistle's volume and pitch follow `car.boost`. - **Skids.** The skid loop's volume follows `car.skid`, and the loop follows `car.surfaceId`: squeal on tarmac, concrete, cobbles, rumble strips and oil (quieter on wet tarmac and ice), crunch on gravel and dirt, scrub on mud, grass, sand, snow and puddles. - **Crashes.** When `car.impactCount` changes it plays a light tap, a medium crunch or a heavy smash, chosen and scaled by `car.impactSpeed`. ## API - `EngineVoice` component, on the chassis. Fields: `voice` (`auto` or a name), `volume`, `maxDistance`, `shiftStyle`, `skids`, `crashes`, `doppler`. `:mix()` reports the voice, smoothed rpm, load and boost, band weights, on/off-load gains and its source ids. - `engineVoices.voices`: `names()`, `has`, `get`, `nameOf(id)`, `idOf(name)`, `attach(car, voice?, volume?)`, `set(car, voice)`, `detach(car)`, `clips()`, `surface(id)`, `firingHz(voice, rpm)`, `loopName`. - `EngineVoiceDemo` component: a stand-in car that writes the `car.*` values (`voice = "cycle"` or a name, `flyby`, `center`, `distance`, `speed`). - `engineVoices.showcase`: `start(opts?)`, `stop()`. - `engineVoices.synth`: `bakeAll()`, `bakeVoice(name)`, `bakeShared()`, `render(voice, band, onLoad)`, `analyze(clip)`. It re-bakes every clip deterministically after a parameter change. ## Cost Per car: six engine sources, a skid source, a one-shot host, and a whistle or inverter source for the turbo, diesel and electric voices. That is 7 to 8 spatial voices, so 8 cars use about 60 of the mixer's 128. The per-frame script is about 0.04 ms per car, around 0.3 ms for eight. The clips are 32 kHz mono PCM loops, 256 KB resident each. ## Clips The engine loops, turbo whistle, inverter, shift sounds and pops are synthesized. The crash crunches, blow-off and the gravel and soft skid takes were made with the engine's audio generation, and the skid takes were cut into seamless loops. The tarmac squeal comes from soundstage's generated skid take, copied in so this package stands alone. They are all in `clips/`. ## Known limits - **#20654** — a car held at full throttle with assists off can spin its wheels without limit; the voice follows the engine's rpm, so that burnout sits on the limiter chop. - **#20569** — the skid sound follows `car.surfaceId`, which torqueCars works out by ray-casting under its wheels because the wheels do not read the ground's named surfaces yet; a car that writes no `car.surfaceId` gets the tarmac squeal everywhere. - **Doppler and distance** — the pass-by pitch drop is the Doppler shift on the voice's spatial sources (`doppler`, 1 = physical, 0 = off); voices beyond `maxDistance` are silent, and with 8 cars about 60 of the mixer's 128 voices are used, so very large fields will steal voices. - **#21241 / #21242** — nothing of the voice is synced: each peer builds the voice from the car's replicated `car.*` values, so a remote car sounds as its owner drives it. - **#20946** — heard and measured on the native desktop engine only; the web build has not been run.