Turn your GoPro into a lap timer
Upload the session you already filmed. Every lap gets timed from the GPS sitting inside the file. No transponder hire. Your MyChron or Alfano still owns the live dash. This is the video-side stopwatch and debrief.
One setup rule that saves a ruined upload
GPS off, or a re-encoded export, and there's nothing to extract. Film original footage with GPS on. The Hero 12 can't do this job at all.
How it works
Film with GPS on
Open the GoPro settings and switch GPS on before you leave the paddock. Leave the camera powered long enough to get a fix. Cold starts with a half-arsed lock are how you get a pretty video and empty data.
Upload the original file
Drop the file into Race Ninja. Don't re-encode it in another app first. That strip of GPS metadata is easy to kill, and then there's nothing to time.
Read your laps
We find start/finish, split the session, flag the fastest lap and give you sectors. Click a time and you land on the matching moment in the video.
Why racers add camera timing to the weekend kit
Nothing extra on the kart for the video path
You're already running a camera for the footage. A hire transponder is collect, fit, hand back, and hope the battery held. Same GoPro times the session once you're home (or between runs).
Times tied to the video
A raw time without video is half the story. When lap 7 looks quick, you watch what your hands and feet actually did. That's what analysis packs are for.
Sectors, not just a single number
Whole-lap times hide the corner that costs you every tour. Sector splits show where the session was really won or lost.
Works with a dash, not against it
Keep the MyChron or Alfano for RPM and temps in the seat. Use Race Ninja for the post-session evidence. Import logger data when you want engine channels on the same timeline.
Different tools, same race weekend
None of these are junk. They solve different jobs. Best weekends usually stack a live dash with a video debrief, not pick a winner.
| Option | What you get | Best at |
|---|---|---|
| Race Ninja + GoPro | Laps, sectors, video, coaching, analysis packs | Post-session precision and proof on film |
| MyChron / Alfano | Live dash, RPM, temps, in-kart timing feel | While you drive and engine health |
| Hire transponder | Official event times when the club runs them | Race control and results |
| Phone lap app | Live times on a phone mount | Quick reference on track (coarser GPS) |
What you get back in about ten minutes
A lap list with your best flagged. Sector splits. Speed through the bits that matter. Coaching notes pointed at the footage, not a wall of charts with no opinion. If you want the deeper debrief, the full analysis page is one click away. This page is the stopwatch. The analysis page is the why.
Common questions about GoPro lap timing
Can a GoPro really work as a lap timer?
Yes. If GPS was on while you drove, the file already holds the track. Race Ninja reads that GPS, finds start/finish, and splits the session into laps. No hired transponder. Nothing extra on the kart.
Which GoPros have the GPS needed for lap timing?
Hero 9, 10, 11 and 13 log GPS when you switch it on. Hero 12 is the odd one out: GoPro dropped the chip, so that model can't produce lap times on its own. Check the cameras page before you film if you're unsure.
How accurate are the lap times?
A modern GoPro logs about ten positions a second. That won't replace a professional timing loop to the thousandth, but for ranking your own laps and seeing which sector moved, it's enough. Most club drivers care about tenths, not thousandths.
Isn't the older 18Hz GoPro more accurate than the newer 10Hz one?
It's the other way round, and the numbers look backwards. Older Heros could sample faster off fewer satellites. The Hero 11 and 13 use a better multi-system receiver (GPS, Galileo, GLONASS, BeiDou). More systems in view beats a higher sample rate off one constellation. Ten good fixes beat eighteen noisier ones.
Do I need to mark the start/finish line myself?
Usually not at a known outdoor circuit. If you're somewhere new or on an odd layout, you can set the line yourself and the laps recut. Indoor tracks are the real catch: no sky, no GPS, no free lunch.
What does it cost to time my first session?
There's a free analysis to start, no card required. Paid plans are for people who upload every weekend. Don't open the pricing page first if you're only testing the idea. Upload a session, see the laps, then decide.
Does this replace a MyChron or Alfano?
No, and it isn't trying to. The dash is brilliant at live RPM, water temp and a quick sense of timing while you're in the seat. Race Ninja is the post-session video debrief: sectors, line, coaching and analysis packs locked to the footage. Plenty of drivers run both. If you've got logger data, you can bring it in to enrich the same session.