Predictive Lap Timing

Instant driver feedback for real-time driver development

Track time is expensive, so finding the best lines and vehicle setup as quickly as possible is very important to both professional and amateur drivers. Predictive lap timing plays a major part in achieving this, especially if it is derived from GPS.

Barff lap timer

What is predictive lap timing?

Predictive lap timing has been available for some time, but traditional methods have generally relied on a distance measurement (normally from a wheel speed sensor input) for calculation. However, distances lap-to-lap almost always change: either by trying different lines, overtaking other cars, or perhaps by locking a wheel. Predicting a lap time accurately using this variable is nigh-on impossible, and is exacerbated on longer circuits.

Unrivalled accuracy using GPS

We employ GPS position from a fast updating data logger - rather than distance - to align the reference and comparison laps. This offers unrivalled accuracy even if the driver takes a completely different line each lap. The system will maintain 0.1s precision the entire way around any circuits, including very long circuits such as the Nurburgring or Spa.

The technology has been built into our high brightness OLED dashboard display, which can be connected to the VBOX in-car camera systems. It is also a feature of our Performance Meters.

OLED Pair 950

It provides drivers with accurate, real-time lap comparison, and it works at any track. You do not need any external beacons, and there is no setting up required.

Predictive lap timing adds another element to data logging, as drivers have a real-time comparison of their current lap against their previously recorded best lap – so they will always be trying to beat it. It means they can judge the effectiveness of different lines and get immediate feedback on the graphical display of how much time they're losing or gaining.

What Racelogic products are suitable for Predictive Lap Timing?

Predictive Lap Timing is available with VBOX Video HD2, Video VBOX, VBOX Sport, VBOX LapTimerDriftBox and PerformanceBox. We claim that this makes us the best value predictive lap timers on the market – with a starting price of just £249+VAT.

Our Performance Meters are already very popular. With their ability to record speed, acceleration, lap times, power and numerous other parameters, they can be found on race and track day cars, magazine road tests, and even vehicle proving grounds.

How accurate is it?

GPS position being used to align lapsAs an example, we can study the two best laps during a race from a professional driver around the 1.6 mile Silverstone National Circuit in the UK.

The rolling distance variation was 11.6m even though the lap time difference was only 0.06s. This equates to an analysis alignment error of 0.3s, and this is around a very short track, with a very good driver. On a longer track with a less consistent driver, this error can easily grow to over 1s!

However, by using GPS position, the timing error between these laps is virtually eliminated. GPS means that the time can be kept accurate to within 1/10th of a second.

Watch the video below to see the standalone VBOX LapTimer in action.


The real time nature of predictive lap timing makes it great for honing racing skills and getting an immediate impression of how much time you are losing or gaining.

It's good for working on techniques such as slip-streaming, because slight adjustments show up immediately in the display. It's also invaluable where there are a variety of different lines that you can take.

On the banked Homestead Circuit at Miami, I was able to see instantly which line along the long banked corner was quickest.

Nigel Greensall, professional racing driver and coach