Per-corner wheel speeds
Standard OBD-II exposes a single vehicle-speed value; individual wheel speeds are not in the SAE J1979 PID set at all. TrackTune reads all four from the head unit’s internal feed, the layer where slip and lockup are visible.
BETA/01 A Miatafy product in closed beta
The telemetry is already in your car.
TrackTune writes it down.
The head unit receives the same internal feed that drives the factory instruments: per-corner wheel speeds, RPM, yaw rate, and dozens more channels, all at once. TrackTune records every drive to files you can open anywhere and puts a glanceable track display on the screen. Nothing to buy, mount, charge, or pair.
- Firmware v74.00.324A
- MX-5 first
- Read-only
- No phone, no dongle, no mount
83 vehicle signals observed on a real MX-5
4 wheel speeds, one per corner
126 records per second, measured on-car
0 things to buy, mount, or pair
§1 · What it does
Channels an OBD dongle can’t reach, with nothing on the windshield.
Every channel at once, no polling
An OBD adapter answers queries one at a time over a shared pipe, so each channel you add slows the rest; Car Scanner measures common Bluetooth adapters at 6–10 queries per second total. TrackTune registers as a passive listener, the same way the factory instruments do. Core channels each arrive at ~10 Hz simultaneously: ~126 records per second measured across the full signal set in a 4-minute hard-driving capture on the ND2.
Nothing to mount, charge, or pair
No phone on a suction cup, no GPS puck to forget, no Bluetooth handshake in the paddock. TrackTune is software on the head unit already wired to the car, and it starts when the car does.
Files you own, in a format anything reads
Each drive logs as timestamped JSON records, retrieved with a USB stick. Open them in a spreadsheet, a notebook, or your own scripts. The setups this replaces: track day data logging.
A display you catch, not read
The screen sits in the center stack, so the mid-corner element is a single grip bar: height is grip used, color says why (cornering, throttle, braking). Stats for each corner post to a Last Corners panel once you’re back on a straight, beside a lap timer on the commander knob and a track map drawn from the built-in GPS.
Against the usual setups
| Phone app + OBD adapter | GPS lap timer | TrackTune | |
|---|---|---|---|
| Per-corner wheel speeds | Not in the OBD-II PID set | No vehicle data | All four, from the internal feed |
| Channel rate | One shared pipe; every channel added slows the rest | 10–25 Hz, position only | ~10 Hz per channel, all channels at once |
| Hardware to set up | Phone mount, adapter, usually a GPS puck | $450–1,000 unit plus a mount | None; it’s the screen in the dash |
| Session files | Per app | Vendor software | JSON over USB, opens anywhere |
Adapter throughput: Car Scanner and the RaceChrono forum. Lap timer pricing and rates: AiM Solo 2 (€430 ex VAT, 25 Hz GPS; the €750 DL adds engine channels through a wired ECU connection) and Garmin Catalyst ($999 list, 10 Hz). Per-corner wheel speed stays absent from those streams on most cars.
§2 · Where it stands
Confirmed, in progress, up next.
Telemetry captured across 26 full drive sessions on a real ND2 MX-5 Confirmed
Speed, RPM, and wheel-speed scaling confirmed against the firmware itself Confirmed
Built-in GPS decoded and merged into the same log, confirmed on-car Confirmed
Gauges and track map running against replayed real drives Confirmed
Gauge display on-car: real corners, real glare, real gloves In progress
Calibrating more signals (G-force, gear, yaw) and more cars In progress
Raising the built-in GPS above its stock 1 Hz Up next
The logger is the proven half. The closed beta puts the display on real cars and calibrates the wider signal pool.
§3 · How the closed beta works
Small groups, real cars.
Ask for an invite
Pick your car and leave your email above. It costs nothing and commits you to nothing.
We invite in small batches
Invites follow the beta's hardware coverage: the right car on firmware v74.00.324A, and an owner comfortable running pre-release software.
Install from USB, then tell us
Beta builds install from a USB stick, the same flow ScreenTune uses, and remove the same way. Feedback goes straight to the developer by email.
- The current beta build and step-by-step install instructions
- A direct email line to the person who wrote it
- A say in what ships in the release version
- Reversible: remove it the same way you installed it
Tell us what you drive and where to reach you. Invites go out in small batches; MX-5s on v74.00.324A go first because that’s the car the data is confirmed on, and other Gen 6 cars follow as calibration grows.
§4 · FAQ
Common questions.
What exactly does it log?
Confirmed and scaled: all four wheel speeds, vehicle speed, and RPM, each checked against the firmware’s own conversion. Captured with known meaning but raw units: yaw rate, longitudinal acceleration, and gear, clutch, and reverse-lamp probes. Beyond that, every vehicle-bus signal the firmware knows is logged raw: 83 distinct signals observed on a real MX-5 so far. Calibrating that pool is beta work.
How fast is the data, really?
Core dynamics channels (wheel speeds, yaw, RPM, speed) each arrive at about 10 Hz, some engine data at 20 Hz, and everything arrives at once: about 126 records per second in a measured hard-driving capture. For comparison, an OBD adapter shares one polling pipe across every channel (Car Scanner puts common Bluetooth adapters at 6–10 queries per second total), and the external GPS puck people add to phone apps is 10–25 Hz of position only (RaceChrono).
What does it show on the screen?
A large speed readout, the grip bar, a braking readout that appears under hard braking, stats for the last three corners (minimum speed, peak lateral G, minimum RPM) color-coded against your session best, a lap timer started and split from the commander knob, and a track map drawn from the built-in GPS.
Where does the G-force data come from?
Lateral G is computed from yaw rate and speed, because the head unit doesn’t receive the lateral accelerometer directly. Longitudinal G arrives as a raw value whose scaling is still being calibrated. Method, error bars, and how it compares with phones and dedicated hardware: G-force accuracy.
Does anything like this exist from the factory?
Almost never, and not from Mazda. The closest factory analog is GM’s Performance Data Recorder, a roughly $1,800 option on performance models (GM Authority). Porsche’s Track Precision app needs the Sport Chrono package and runs on your phone. Nothing factory-native exists for Mazda.
Is this an engine tune?
No. Despite the name, TrackTune never touches the engine, ECU, or anything that moves the car. It runs on the infotainment unit, reads data, and displays it. For actual ECU work, see ND ECU reflash.
Can it affect how the car drives?
No. The listener code contains no send call: it registers for the vehicle data feed the same way the factory instrument software does and transmits nothing to the car’s network. The head unit itself is not wired to the engine, brakes, or steering. Risk picture for factory-screen changes in general: safety and risk FAQ.
Do I need any extra hardware?
No. TrackTune is software on the factory head unit, installed from a USB stick with the same flow ScreenTune uses, and removable the same way. The vehicle data comes from the head unit’s existing connection to the car.
Which cars can join the beta?
Gen 6 Mazda Connect on firmware v74.00.324A. MX-5s go first because the data scales are confirmed on an ND2 MX-5, but plenty of Mazda3s and others see track days too, and confirming their data is part of the beta. Full list: supported vehicles.
What does the beta cost, and what am I committing to?
Nothing and nothing. Signing up puts you on the invite list. If we invite you, you get the build and instructions by email, and what we ask for is feedback: what worked, what didn’t, and, if you’re willing, your drive logs.
How does this relate to ScreenTune?
ScreenTune is the shipping product and the installer. TrackTune installs through the same flow and is planned as its track-focused big sibling.