Quarter mile times on the iPhone

I finally gave in last week and bought an iPhone. I’d been trying to resist for ages, and bought the LG U990 (supposed iPhone-beater) just at the start of the year. But the one thing the LG taught me was that tech specs don’t count for anything – it’s the quality of the UI that’s most important, and that’s what Apple have got right.

My first paid-for App Store purchase was Dynolicious, one of the many car speed/performance apps already on the market. What really appealed about Dynolicious over the competition was that it didn’t use the GPS at all. Instead, it relies on the built-in accelerometers and some clever physics to work out the acceleration (and therefore speed) of your car.

Dyno GraphI was already fimilar with performance meters that work this way, having played with my friends G-Tech Pro a few times over the years. I’d actually considered buying a G-Tech myself, but couldn’t really justify the 250 or so it cost for the odd occasion I’d use it. But a 7.95 app for a device I already own? …much more interesting!

I’ve read a lot about the impressive accuracy of Dynolicious online and have to say it seems pretty damn accurate.

First I tried the 1/4 mile timing. You just press the ‘start run’ button and it waits for you to move off. As soon as it detects a movement of over 0.1G (configurable) it starts the timer. Again, the results seem really accurate. Compared to my TomTom GPS the terminal velocity of 83mph was bang on and the 0-60 time of 9.69s felt spot on too (the quoted figure for the IS200 is 9.5s and I expected to be slightly slower given the cold damp road surface at the time of the test).

Next I gave the skidpan feature a go and managed to rack up a Lateral G figure of 0.90 and a Braking G of 0.86 on the local roundabouts. I have less hard facts to judge these on, but again they felt about right, my braking being less effective than the cornering due to the ABS kicking in.

All in all I’m dead happy with it. The only thing I’d like to see in a future revision of the software is a way to store and review the dyno graphs it captures during a run. The graphs — showing BHP, torque and speed — have an impressive level of detail that I’d like to take a look at later. For example, you can clearly see the length of time you lose on each gear change.