Trackday Pyrometer Helper — User Manual

What this app does

Trackday Pyrometer Helper is my one-screen-per-job track app: tire temps from my PyroTC BLE pyrometer, hot/cold pressures from cheap BLE TPMS sensors (Zeepin and DJTPMS), an all-day background pressure monitor, per-tire heat-cycle tracking, corner balance with ProForm wireless scales, and packing checklists. Everything is on-device — no accounts, no cloud.

This is the manual I wish I’d written earlier. It’s ordered the way you’d actually set the app up.

The main screen

The TIRES tab: session log grouped by track and day, static camber at the bottom.

The header has four buttons: TPMS (sensor setup), MON (background monitor), ⇣ (CSV export of everything), and ⚙ (settings). The CAR dropdown switches between car profiles — each car keeps its own weights, camber, targets, and sessions. The TIRES / BALANCE tabs switch between pyrometer work and corner-weighting.

First-time setup: TPMS colors

Everything pressure-related hangs off one idea: paint each valve stem a color (I use Posca PC-3M paint markers — the app’s color list matches my 14-marker kit) and teach the app two things:

1. SENSORS — which color is which sensor. Tap SCAN, roll the car a few feet so the sensors wake, then tap a color chip and tap its sensor in the DISCOVERED list. Do this once per sensor, ever.
2. WHEELS — which color is on each corner right now. Tap a corner, pick a color.

Wheel map on top, tagged sensor library below. Zeepin and DJTPMS sensors can be mixed — the type is auto-detected when you bind.

Two-tone stems (my spare is half red, half white) get the + SPLIT button: pick two colors and the app builds a “Red/White” label with a split swatch.

When you rotate tires, this is the only screen you touch — re-point the colors to their new corners (or save layouts as named SETS and load one with a tap). Every other feature resolves corner → color → sensor at the moment it’s needed, so rotations propagate everywhere automatically.

Tire inventory and heat cycles

Settings → Tire inventory. Each physical tire is its own record with a heat-cycle count and corner history.

ADD SET creates a whole numbered set in one tap and binds your current corner sensors to it.

• ADD SET — type a base name, pick a compound and count, done. “sm7.5 #1…#4” are created and each gets the sensor currently on its corner, so cycles start counting immediately.
• Heat cycles log themselves three ways: the background monitor detects a heat-up/cool-down on track, SYNC HOT after a session, or the manual +CYCLE button (tap it N times to back-fill N known cycles — it’s never deduped; the automatic paths dedupe to one cycle per 10 minutes so a single session isn’t double-counted).
• The corner is recorded per cycle, so a tire’s history reads like LF×4 RF×2 — rotations captured for free.
• RETIRE keeps history and frees the sensor; UNRETIRE brings a tire back; long-press a tire card to delete it entirely. Everything destructive asks first.

If a tire shows an amber “no sensor” warning, automatic cycles can’t reach it — assign its sensor.

Recording a tire-temp session

Tap ＋ NEW on the TIRES tab. The new session inherits everything from the last one (tire, unit, location, toggles), auto-numbers itself within the day, and — if the tires in your inventory are sensor-bound — names the tire set automatically.

Each corner block shows which physical tire is on it (sm7.5 #1, #2…), resolved live through the sensor chain.

My session flow:

1. AMBIENT ⇣ GET — pulls local temperature (Open-Meteo) so the app can verify the tires are actually cold.
2. ⌖ NEAREST — auto-fills the track from a bundled list of ~1,900 circuits (works offline; paddocks have no signal).
3. SYNC COLD PSI — one tap grabs every corner’s TPMS reading.
4. Run the session.
5. SYNC FROM PYROMETER — record OUT/MID/IN on the PyroTC gun, hit sync, all twelve cells fill over BLE. Take temps immediately — they fade fast.
6. SYNC HOT PSI — hot pressures land per corner, and a heat cycle is logged on each tire that reported.

Set a HOT TARGET per tire model once and the app derives the rest: the bleed amount (“bleed 1.5 → 32 psi”), and a predicted COLD START pressure computed from your own measured cold→hot rise — ambient-aware, so a cold morning’s +6 psi doesn’t pollute a hot afternoon’s prediction. Until there’s history it assumes ~3 psi and refines as you log.

The collapsible RECOMMENDATIONS section reads the temp spread per tire: inside-vs-outside drives camber advice, center-vs-edges drives pressure advice.

Background pressure monitor (MON)

Live corner cards with the wheel-map color tags; logged runs below.

MON runs as a foreground service and logs every corner’s pressure and temperature all day, even with the app closed. I switch it on in the paddock while the tires are cold and off at the end of the day.

• Tap a live wheel for that corner’s full pressure + temperature chart; tap a logged run for all four corners. Charts have a real time axis — points are placed by elapsed time, min/max are marked.
• Every run can be exported to CSV from the LOGGED RUNS list.
• It’s also the heat-cycle auto-detector: a corner that climbs 20°F and falls back 15°F counts one cycle on whatever tire is there.

The notification shows per-corner psi/°F and has a Stop action. Off by default — it costs battery.

Corner balance

Cross weight with the RF+LR diagonal highlighted. MANUAL entry or LIVE SCALES.

The BALANCE tab computes cross weight (RF+LR as a percentage of total) from four corner weights — typed in, or streamed live from ProForm wireless scale pads over BLE.

• SCALES › opens setup: map pads to corners (AUTO-STEP walks you around the car), calibrate each pad once with a known weight, and ZERO before rolling the car on.
• In LIVE mode, CAPTURE freezes the current weights into the car profile and drops back to MANUAL so the numbers hold while you turn perches.
• The recommendation card tells you exactly how much weight to move onto or off the RF+LR diagonal, which corners to raise or lower, and — once you calibrate lb-per-turn — how many perch turns that is.

Scale in race trim: driver weight in the seat, fuel set, ride heights where you want them.

Settings, checklists, backup

App-wide items on top; per-car tire interpretation targets below.

• Theme — Daylight (default, built for direct sun), Dark, or follow the system.
• Packing checklists — reusable lists (Day Drive / Tow / Camp presets); check items off as you pack, UNCHECK ALL resets for the next event, SHARE sends plain text to Keep.
• Backup — one JSON file with every car, sensor, tire, and checklist. Export before phone swaps; restore replaces everything. Monitor logs aren’t included — export those runs to CSV if you want to keep them.
• Tire targets — the camber-gradient and pressure-band thresholds the recommendations use, per car. Defaults follow the SuperMiata radial guide.