1. How do I use TPA Racing?
A. First you select the measurement unit type you want under the TPA Racing part of the iPhone/iPod Touch settings and then you enter the total weight of your car including yourself.
Secondly, you secure the device in your car holder (for best accuracy we recommend it to be upright like in the pictures on the homepage but it can also be tilted forward or laying flat facing forward, just remember to let us know how you place it when you submit test run information).
Last press start and wait for the application to calibrate, when it says "Accelerate when ready" you are ready to go. If you find that the device is too sensitive at take off you can adjust the take off threshold (default is 0.3g) so it won't start until you take off.
2. I just installed TPA Racing and I want to use km/h and kg but under settings it is already selected even though I have mph and lbs in the application. Why?
A. Version 1.0 of TPA Racing is not showing the correct default value for measurement type. Simply select mph/lbs and then select km/h and kg again. Now you will have the desired setting in the application. This is fixed in version 1.1 .
3. Is the weight recalculated when you change measurement type?
A. No, you will have to change the weight manually. From version 1.1 the weight measurement type will be shown after the weight for clarity.
4. What kind of accuracy can I expect from this application?
A. The tests that have been made by independent test authorities show that the times are within 0.25s and the speed figures within 1mph of what you will get with standalone equipment that costs hundreds of dollars.
5. How do I place the iPhone for best accuracy?
A. Tests have shown that an upright position facing the direction of travel will produce the most accurate results. Also make sure the test track is fairly straight and level.