Tested: 0-60 MPH Times, Dynolicious iPhone Application Versus VBox
Yesterday we ran a news story about a new iPhone application that uses the phone's accelerometer to record "accurate" performance measurements for your car. At $12.99, it seemed like too good a deal. So we bought it, then stuck it on the windshield of an Audi S5 alongside the VBox we use to record our own acceleration figures, track times, and G-forces. Jamie's results are after the jump or in our forums below.
Ok, I just did impromptu testing between the Dynolicious and one of our VBOX units. Unfortunately the point and shoot camera focused on the background in this shot of the setup instead of the equipment, but you get the gist of it.
One-foot rollout was turned off on both units and the VBOX data is raw (non-corrected). The car used was an Audi S5 and I didn't bother beating it to death on the launches. The point here was a comparison, not a record 0-60 mph run.
Here are photos of each of the data screens:
In 10 runs back and forth to 60mph, the average difference between the two units was 0.45 seconds with the VBOX delivering quicker numbers. However the discrepancy on different runs between the two fluctuated from a 0.24 difference on one run to a 0.65 difference on another. We dropped the highest and lowest fluctuations and averaged the remainder.
It is important to note that the VBOX is using GPS data and yaw sensor data to achieve its figures. The Dynolicious software is only using yaw data from the iPhone. A base level VBOX Performance Box costs $499. The unit we used originally started as a VBOX Driftbox but was upgraded to a VBOX MINI later in its life. Most all of the major magazines use Racelogic VBOX hardware for their performance testing. The units used vary from simple Performance Box units to full blown $10,000+ VBOX III data recorders. VBOX certifies the accuracy of their units to be within +/- .01 kph of actual speed. The magazines also correct all their acceleration figures for weather and altitude. Plus they usually factor in a one-foot rollout (as used on a 1/4 mile dragstrip) into acceleration figures which generally results in a 0.3 second lower 0-60 time. Our opinion is that the one-foot rollout is fine for 1/4 mile times as that's how it is done at the strip. However subtracting the one-foot rollout from a basic 0-60mph time is just making the figures even more impressive (and unattainable by most people that buy the car).
The VBOX unit had fairly consistent runs across all 10 passes. The Dynolicious software varied a bit more between runs.
Draw your own conclusions.