01
Live HUD
Slip angle, speed and G, big enough to read in your peripheral vision. Voice callouts, a peak hold, and auto-record: a run starts itself when you roll.
Drift telemetry · free · no hardware
Every drift,
measured.
YAW turns the phone on your dash into drift telemetry: live slip angle, G and speed, every run graded against your best, and a coach that names the one thing to fix next. No hardware, no account, and it works where the track has no signal.
iPhone and Android · installs from the browser · your runs stay on your phone
sample run · Sonomameasured
62°
right · slip angle
speed
62mph
lat G
0.96g
on angle
0.6s
60 Hzmotion read and fused on the phone
1–2 sof GPS lag learned for your phone and taken out
800+automated tests on every release
0accounts, ads or trackers
Live demo
See it running, right now.
Four cars on Sonoma Raceway's real circuit, each replaying a real lap an S14 drove there: its angle, its speed, the corner it's in, and the board an event's big screen shows.
Loading real laps…
live demo · Sonomareal laps, replayed
01 — What it does
Built for a drift day, start to finish.
Everything between the first warm-up and the drive home, on the phone you already carry.
02
Judge & Coach
Every run graded on line, angle, speed and style against your own best run at that track, zone by zone, with one drill for next time.
03
Laps & sectors
Laps found on their own, sectors split, and your best-lap delta flashed the moment you cross the line.
04
Lap compare
Two laps laid over each other by position: where the time and the angle came from, corner by corner. Yours, or one another driver sent you.
05
3D replay
Your run rebuilt over satellite imagery: the car's footprint, its drift lines, and the gap to the car in front.
06
Tandem
Lead and chase phones linked live: the gap in metres and seconds, and how closely the chase matched the angle.
07
Events
A big screen for the paddock: every car live on the map and a board you can read from across the tent. Drivers join with a QR code.
08
YAW Cam
Anyone's camera, with the car's speed and drift angle burned into the video. Ride along, film from the fence, or hype the car on track.
Tracks
Satellite maps with the circuit drawn in, it finds the track you're at, full guides for Sonoma and Thunderhill, and Thunderhill West's ten corners ready to use as your course.
Your car
Two photos of your car become the car in the replay, paint and stickers and all.
Your data, out
CSV, MoTeC for Assetto Corsa, GPX for any map, and a full JSON backup. Nothing is locked inside the app. On your sim PC, YAW Sim puts a real run into Assetto Corsa as a ghost to chase.
02 — How it measures
Your phone has the sensors. YAW keeps them honest.
No box to buy and nothing to wire. The phone in its mount already knows how fast the car is turning and which way it's travelling. The work is in reading that truthfully.
slip angle = heading (gyro, 60 Hz) − course (GPS, lag removed)
Slip angle, from motion
The gyro says which way the car points; GPS says which way it's going. The angle between them is the drift, and YAW fuses the two: the motion sensors sixty times a second, the GPS about once. It's an estimate, and it says so.
Built around a late GPS
A phone's GPS reports where you were a second or two ago. YAW learns that lag for your phone, and how the phone is mounted, takes both out, then reads the whole run again with them.
Estimated stays estimated
Every run says how much of it the angle estimate held. Stretches with no GPS are drawn dotted. A run that can't be trusted says so instead of being scored anyway.
Honest about the limits
Phone GPS is good to a few metres in the open, not the centimetres of RTK, and can be tens of metres off beside a big steel grandstand. Grades are against your own benchmark, not a judge's line. Judging is partly subjective; the numbers are estimates, not measurements.
03 — A day at the track
From the paddock to the drive home.
Four moments where YAW earns its place on the dash.
01
Before
It finds the track you're at by GPS. Ten seconds of sensor checks, and you're ready.
02
On track
Auto-record starts a run when you roll. Angle, speed and G live, and a callout when you set a best lap.
03
Between runs
A grade, a cue and a drill before the next run. Your best lap alongside in two taps.
04
At home
Replay it in 3D, chase it in the sim, watch the trends, keep a logbook. Export to MoTeC, CSV or GPX when you want to dig.
04 — Events
Running an event? Put it on the big screen.
Start an event on any phone and open it on a TV. Drivers join with a QR code, no accounts, and every car shows up live on the map, with boards for best angle, most time on angle and most improved. Tap any driver to follow them in 3D. Each driver sees their own day on their phone, first run to last, and results export when you're done. List it, and anyone who opens YAW at the track while it's on is offered it — no code to type.
Watch the demo event — real laps at Sonomabest angle · example board● 4 on track
P1AlexS1441% on angle58°
P2JoE3636% on angle52°
P3RaeFC RX-733% on angle49°
P4Sam350Z29% on angle44°
05 — For everyone watching
Watching? You're in the show now.
YAW Cam puts the car's numbers on your phone's camera, and the crowd's noise on the board. No app store, no account — scan, point, tap.
Film it with the numbers on.
Scan the code on the event's screen. Your camera shows the car on track — name, handle, speed, angle — and it's recorded into your video with the sound.
Tap to hype.
Flames burst where you tap. Everyone's hype rises on every phone and the big screen, every run gets its crowd, and the run the most fans hyped is the crowd favourite.
Clip it after it happens.
The camera keeps the last ten to twenty seconds: tap Clip when it's over. Or set it on Tripod and every car that passes you is clipped by itself.
Tagged, ready to post.
Drivers' Instagram handles go on every video and its caption. And at the end, “I was there” turns your day at the fence into a story.
● LIVE YAW EVENT K7P2Q · 87 IN THE CROWD
HYPE CHECKTAP FOR RAE 9
▮▮▮▮▮▮▯ 33 FANS
RAE@rae.e36 · E36 · T3
44MPH
52°ANGLE
06 — On your sim PC
Your real runs, in the sim.
YAW Sim, for Windows, connects the car and Assetto Corsa: the same runs, both ways.
Chase your run.
A run from your phone shows in Assetto Corsa on the same track, as a ghost car at the angle YAW read. Chase it, or drive beside it.
Sim vs real.
Sim sessions come back to YAW. Where a track has both, your sim lap is laid over your real one, corner by corner.
Clips by themselves.
Every session is cut into short vertical clips of its best moments, with the angle gauge on. A button on the wheel marks “that one”.
The Windows download is coming. What YAW Sim does
07 — Privacy
Your runs are yours.
No account.
Nothing to sign up for. Your runs, courses and videos live on your phone.
No trackers.
No ads, no analytics, nothing about you collected, sold or shared.
No public ranking.
You're only on a board when you join an event, and only for that event.
What's yours stays free for good: recording, your runs and getting them out, your place on an event's board, and YAW Sim. An optional backup is on the way: six words, no email, nothing else. Read the privacy page
08 — Built carefully
Built for race weekend, not a demo.
Every release runs more than eight hundred automated tests. It opens and records with no signal. A run survives the app being killed mid-session. And the self-test shows, in ten seconds on your own phone, that everything is working before you roll out.
YAW measures what you do. It doesn't make it safe. Drift at events and on closed courses, within your limits and the organiser's rules, and never touch the phone while the car is moving.
Your next run, measured.
iPhone: open YAW in Safari → Share → Add to Home Screen.
Android: open it in Chrome → Install app.