Know which corner cost you.
A lap timer for your phone that tells you where the time went, corner by corner, and what to change on the next lap.
LaptimerTimeAttackRun
LapTAR comes inside the TimeAttack.pt app: install it and open the Timer tab.
The app, as it is today.
Real screens from the current build. On track you read one big number at a glance; in the paddock every lap opens up.
The car, on your video.
Pair an OBD adapter and the overlay grows an engine: RPM on its own dial, throttle and braking as bars and traces, intake and coolant temperatures in the corner. The coach's call lands on the footage too, and so does the verdict.
One corner, four fixes.
Turn 1 at Estoril on lap 22: the times and fixes from the analyser, the grades from the corner card. Each part of the corner gets two answers: the time it cost against your optimal lap, and how much of the car you used. Tap a part for the fix.
Brake+0.22weak
Braked 10 m before the optimal lap, arriving at 175 km/h where it arrived at 181.
Trail+0.11coasted
Coasted between letting go of the brakes and turning in, instead of carrying the brakes towards the apex.
Turn+0.22at the limit
The car was at its limit here, so there was no more speed on this line. Lap 23 went through on a different line, and that is the one to copy.
Exit+0.06at the limit
At the limit again: the exit lost its time to the line, not to a lifted foot.
Why can "at the limit" still cost time?
The two columns measure different things. vs your optimal is time: how this part of the corner compares with the best you have driven it. vs the car is grip: how close you were to what the car can do on the line you took.
So a part can be at the limit and still slow, when the car was working flat out on a slower line, as in the turn above. And a part can be graded weak while costing almost nothing, when you left grip unused but the line made up for it. The fix tells you which one to work on.
What is the optimal lap?
Your own best corners, joined on the straights, and never slower than any lap you drove. It is not a faster driver's ghost: the gap it shows is time you have found at least once. On 13 Sep at Estoril the best lap was 2:10.500 and the optimal 2:09.191.
The live screen can chase the optimal or the session's best lap; you choose on the Timer tab.
Everything it does.
A lot happens behind one number. Open anything to see how it works.
On track
Live deltaAhead or behind, in one number you can read at speed.
The top of the live screen is the gap to your reference lap, updated as you drive, green when you are ahead and red when behind. Below it, your speed against the reference at the same point, so you see where the gap is being made.
Corner verdictsBrake, trail, turn and exit, graded as you leave each turn.
Each turn is split into four parts. As you leave it, the card shows the time each part cost against your reference and how much of the car you used, with the entry and apex speeds beside them.
Voice coachOne instruction before a corner, a verdict after it.
From the laps you have already driven, the coach picks what to work on and says it before the corner, for example "Next left. Brake 30 metres later." After the corner it says better, worse or the same, and calls the lap at the line. Corners are named by their direction, so you never count turns.
GPSThe phone's own GPS, or a Bluetooth receiver.
The phone alone times every lap. You can also pair an external Bluetooth GPS receiver; the satellite count and the receiver's state sit at the bottom of the live screen.
Sessions that resumeStop for the pits, carry on the same session.
Stopping saves the session. Resume it later and the new laps join it, with the lap that spans the break flagged so it never counts as your best.
In the paddock
Where the time isThe corners worth the most, each with its fix.
Every session opens on its best and optimal laps, the car's peaks (top speed, lateral and braking g, and engine temperatures and RPM with OBD), how consistent your best laps were, and the corners that cost the most against your optimal, each with the change to make.
AnalyserMap, traces and channels for any lap.
Pick a lap and a corner: a satellite map with your line, traces of acceleration, braking, throttle and RPM, and a list of fixes for that corner with what each one costs.
Lap tableEvery lap and every number side by side.
Lap times, top speeds and apex speeds for every turn, the best and worst in each column marked. Breaks between runs stay visible, and from any lap you can analyse, upload, share or export its overlay.
Track trendsEvery turn followed across your sessions.
For each circuit, each turn's best and typical time, apex speed and braking, session after session, so you can see what actually improved. Filter to dry sessions only.
Setup sheetTyres, pressures and geometry with every session.
Note the tyres, cold and hot pressures and geometry for a session, save it as a named setup, and mark the surface dry or wet. Named setups show up in the trends.
Overlay exportYour lap's numbers on your onboard video.
Export any lap as a video overlay to lay over your camera footage in an editor: a keyed MP4 that works everywhere, or a transparent MOV or WebM. 720p, 1080p or 4K, at 30 or 60 fps, with the lead-in and lead-out you choose. With an OBD adapter it also shows RPM, throttle and engine temperatures.
Your kit
OBDThrottle, brake, RPM and more, per car.
Pair a Bluetooth OBD adapter and choose which channels to poll fast; fewer channels update faster. Each car keeps its own channels, custom PIDs and alerts. Optional: everything else works without it.
GarageSeveral cars, each with its own profile.
Keep every car you drive. The car you pick decides the OBD profile and is noted on each session.
RaceChrono importBring the sessions you already have.
Import RaceChrono sessions and they get the same analysis as laps recorded in LapTAR: optimal lap, corners, trends.
CircuitsNearest first, or a round from the calendar.
Choose the circuit before you start, nearest first, or pick a round from the TimeAttack calendar. From the lap table, a lap can be uploaded to the round's results.
Questions.
Do I need any extra hardware?
No. A phone in a mount is enough for lap times, the live delta, corner verdicts and the voice coach. An external GPS receiver and an OBD adapter add to it.
Why is it inside the TimeAttack.pt app?
LapTAR is built by the people behind TimeAttack, the Portuguese time attack championship. It ships inside the same app, so the laps you time can go straight to a round's results.
Where do I find it after installing?
Open the TimeAttack.pt app and go to the Timer tab. Recorded sessions are under Sessions.
Can I try it before a track day?
Yes: the Timer tab has a demo run at Estoril that plays through the live screen, delta, corner cards and all.
Next session, coached.
Install the TimeAttack.pt app and open the Timer tab.