John K Posted July 21, 2014 Share Posted July 21, 2014 Chaps, I'm extremely sceptical about how ( or even if ) any of these smart phone 0 to 60 apps work. Has anybody tried any and compared them to a proper timing rig? If they are even close to accurate, I am happy to waste a few pennies on getting one. BTW would have to be Windows phone compatible, I only have a work phone and they swapped my beloved Nokia 3109 for some Carlos Fandango all singing all dancing Nokia Lumia thing. Which I can't use... Quote Link to comment Share on other sites More sharing options...
SootySport Posted July 21, 2014 Share Posted July 21, 2014 Satellites just wouldn't keep up with my car , I'd be doing 60 before they realised I moved. Quote Link to comment Share on other sites More sharing options...
Onliest Smeg David Posted July 21, 2014 Share Posted July 21, 2014 Tried some, The refresh rate of a phones gps is not up to the task. Quote Link to comment Share on other sites More sharing options...
Dibby Posted July 21, 2014 Share Posted July 21, 2014 Useful for tracking a blat about the hills if that's your bag but not for a single 0-60 shoot out, nowhere near accurate enough. Mountain bikers and runners use them a lot for training and local king-of-the-mountain records are highly prized on a pedal bike, the GPS trackers are pretty iffy at best and regularly get confused with what trail you're riding on at walking pace, let along being accurate enough to time a 0-60 run in a car. Quote Link to comment Share on other sites More sharing options...
TAFKARM Posted July 21, 2014 Share Posted July 21, 2014 I thought they worked off the phones internal accelerometer, rather than a GPS signal? Quote Link to comment Share on other sites More sharing options...
SootySport Posted July 21, 2014 Share Posted July 21, 2014 It would only be measuring the G force of the car, other new cars have them these days. It's time over distance that measures the 0-60 and would need satellite tracking for that, besides they are only accurate to 10metres I believe for public consumption. Quote Link to comment Share on other sites More sharing options...
TAFKARM Posted July 21, 2014 Share Posted July 21, 2014 It would only be measuring the G force of the car, other new cars have them these days. It's time over distance that measures the 0-60 and would need satellite tracking for that.If you sampled regularly enough you could use the equations of uniform motion to calculate 0-60 if you know the acceleration rate (i.e 'G force')http://en.m.wikipedia.org/wiki/Equations_of_motion ETA: Here you go, second paragraph http://www.bunsentech.com/products/dynolicious/index.php Quote Link to comment Share on other sites More sharing options...
Kevin Jones Posted July 22, 2014 Share Posted July 22, 2014 The basic problem is the error rate on the accelerometer increases with the square of time, you need an external reference (such as GPS) and some fairly serious maths to keep the errors under control. Upshot I guess is that some app/phone combinations will work much better than others due to sensor differences and how well the app handles the errors for that sensor. Quote Link to comment Share on other sites More sharing options...
alexander72 Posted July 22, 2014 Share Posted July 22, 2014 I had one but it couldn't keep up with the mighty cross flow powered red and black beast Quote Link to comment Share on other sites More sharing options...
Welly Jen Posted July 24, 2014 Share Posted July 24, 2014 If you sampled regularly enough you could use the equations of uniform motion to calculate 0-60 if you know the acceleration rate (i.e 'G force') http://en.m.wikipedia.org/wiki/Equations_of_motion ETA: Here you go, second paragraph http://www.bunsentech.com/products/dynolicious/index.php Inertial navigation. Used by people with ICBM's to drop a nuke on a city from half way round the world. As has been mentioned the inaccuracy builds quickly. One of the reasons GPS was invented was to increase the accuracy so you could drop a bomb on some ones front porch from half way round the world. Not tried one of these phone apps, but the accelerometers in phones are used to supplement the GPS for navigation. Especially useful in places like cities where tall buildings can restrict the number of satellites the phone sees. It will help keep you on track till the next decent GPS fix. Jen Quote Link to comment Share on other sites More sharing options...
FILFAN Posted July 24, 2014 Share Posted July 24, 2014 The biggest problem I see is the speed of the built in GPS receivers. The iphone only has a 1hz receiver and allot can happen in a second. You can buy after market Bluetooth ones around 10hz but that just makes it expensive. Quote Link to comment Share on other sites More sharing options...
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