Know that overwhelmed feeling you get when leaving the pits for the first time? It's normal, especially if you don't have a driving coach sitting next to you or a crew chief on the radio focusing on your weak points. It's likely you don't even know what your weak points are.
One easy and increasingly affordable way to improve your track driving is to use an inexpensive data logger. They come in many forms, from free smartphone apps to stand-alone devices. When you consider the investment you've already made to take the green flag, the extra cost to log and analyze your time is minimal. You just need to know what to do with the data when you're done.
We looked at several options under $500. All let you record the prime information that pro instructors seek: speed-versus-distance and longitudinal acceleration. Each of these options can also incorporate video, so you can play Diffey-Matchett and numerically dissect your mistakes in slo-mo.
Racelogic VBOX Sport
- Cost: $429
- Special Features: Super-accurate 20-Hz position and speed sampling
- Works With: Harry's LapTimer (opposite), Racelogic apps (VBOX Sport Performance Test, Diagnostics, Laptimer)
- Video: Through Harry's LapTimer
- Bottom Line: This is Racelogic's latest entry-level product. (R&T uses the professional VBOX for vehicle-performance tests.) Run it blind to record data straight to an SD card, and then use Racelogic's high-end data- analysis software, Circuit Tools, to pick everything apart after the fact. Or pair with an iPhone to provide GPS data to Harry's LapTimer or Racelogic's own no-frills, free Laptimer app. The self-contained Sport is waterproof and has a built-in battery, so you can use it on your dog, your Jet Ski, your flying submarine—practically anything.
G-Tech Pro Road Racer
- Cost: $300
- Special Features: Graphical real-time coaching
- Works With: Fanatic PASS software for larger displays and lap-time overlays
- Bottom Line: In a small, simple, built-in display, the Pro shows segment splits with a thumbs-up or thumbs-down graphic designed to catch your peripheral vision and let you know how you're doing. There's a replay function for review on the tiny screen, and the chart format shows acceleration curves in g's, which is useful to find where you're spinning the wheels and how quickly you overcome transitions from shifts, as well as how efficiently you're using the brakes. Not a ton of features, but the ones it has are easy to use.
- Cost: $400
- Special Features: Rare-earth magnets stick it to anything ferrous
- Works With: OBD II (requires $700 DL model)
- Video: Up to two cameras (requires $700 DL model)
- Bottom Line: The Solo's backlit monochrome display shows predictive and actual lap times, speed, and acceleration. The big deal with this little guy is huge numbers that make it easy to peek at while on track. The included Race Studio 2 analysis tool is highly accurate and offers pro-level performance measurement. No metal in sight? Stick it to the windshield with a suction mount (Ram Mounts, $45).
- Cost: $7
- Special Features: OBD II integration
- Works With: Internet-streamed data and video, iPad for in-car telemetry
- Video: Up to two cameras (iPhone camera, Wi-Fi-enabled GoPro)
- Bottom Line: Displays lap times, compares laps, and does video data overlay. The app can also read and reset OBD II codes. Free to sample but will only remember two laps; you'll need the pay version beyond that.
Harry's Laptimer Grand Prix
- Cost: $28
- Special Features: Screen flickers red over 1.0 g acceleration, OBD II integration
- Works With: V-Box Sport (opposite)
- Video: Multiple with picture-in-picture (iPhone camera, paired iOS devices, GoPro Hero3)
- Bottom Line: Overlay video with a map, speed, and other data, creating something like what you'd find on a TV race broadcast. The video can be quickly reviewed and mixed, with fast laps compared to slow ones. There's a detailed online manual, rare for an app and helpful since powerful features are constantly being added.
- A good mount keeps the data clean. This Ram Mount ($40) lets you see the phone while the phone's camera sees what's ahead.
OBD II, Brutus?
- You may want to know when an early lift or late braking is stabbing you in the back. The OBD II data feed from a 1996-or-newer car will supply that info. Most of these systems work with Bluetooth dongles; some need a cable.
Throw Money At It
Traqmate Traqdash HD Complete
- If you want to get more serious, consider something from Traqmate. The Traqmate Basic ($1000) samples at 40 Hz and bundles a camera controller and tach input, but if you're spending, why not go for the $2313 TRAQDASH COMPLETE? It includes a Replay XD1080 camera and the TraqDash color touch-screen display ($800 by itself), which gives instant feedback on corner speeds and how you're meeting predictive lap times, and can take the place of a traditional instrument cluster. Like Circuit Tools, the Traqview software will compare laps to a theoretical ideal time.
- Predictive lap timing is the best way to on-the-fly improvement. You'll know whether you're stringing it all together or if it's time to go back and adjust.
What do I do with all this Data?
By David Gluckman and Marshall Pruett
Bring your Laptop
- You'll want to go over the data and video when the track is fresh in your mind. Bring an extra battery or a power inverter and whatever cables you'll need.
- Set up repeatable, real-world tests for yourself. Choose a recognizable marker point and try early turn-in three times, then switch to later braking with late turn-in for three laps. Maybe an extra downshift before a slower turn will help. You won't know until you try.
Letters to Myself
- Put a sticky note on your steering wheel with the list of different things you're going to try. (And so you remember the milk.)
Adjust one thing at a time
- Respect the scientific method. Make one change and keep everything else constant so you can reproduce what you did. Be sure to record some hot laps with the car and tires fully warmed up before making changes, too.
The most important corner
- Focus on the turn leading onto the longest straight. This is where you'll make up the most time, so carrying the most speed through is crucial. See what it gets you at the end of the straight, not just corner exit.
- Your car club may have an instructor or "fast guy" who can get more out of the car than you can. Put him in the seat to set some lap times. While it may not directly translate to your driving style, it will show what your car is capable of.
A case of the squiggles
- Every analysis software will work differently, but the main items to focus on are speed-versus-distance and longitudinal acceleration. That will show you how fast the car is going at any point on the track and whether you're on the brakes, on the gas, or just coasting.
- The change in time, or Delta T, in a segment between one lap and the next can teach you a lot. Some software will piece together an "ideal" lap to reference.
Braking or lifting?
- There's a difference. If you don't have an OBD II stream to show when you're on the big pedal, try aiming a camera at your feet. That, the lap trace and acceleration data, will tell you where you're wasting space on the track.
One for all
- If you're running just one camera, try to get as much in frame as possible. Helpful areas: the steering wheel, what's out the windshield, the tachometer, the shifter. It's tough to get it all in one shot, which is why video-overlay capabilities are a big help.
Test and Tune
- Trying out new tires or suspension-geometry changes? The same rules apply: Put down reference laps with the original setup, swap parts, see what it does for you. Remember that new equipment may also require changes in technique.