Originally Posted by Merlinshawn

Do you have the Kiwi 1 or 2?

I have been playing around with some of the track apps and I have the OBDII PLX Kiwi 2 Wifi. I like Harrys Lap Timer, except that it relies on the GPS refresh rate to recorded data.

I have an iPhone 4s and the internal GPS refreshes its self once a second or 1 Hz, my OBDII Kiwi 2 refreshes 6 times a second or 6 Hz. Since Harrys Lap Timer is heavily GPS based its only recording data once a second and dropping a lot from the OBDII. It even drops a lot of the accelerometer data, it refreshes at 31 Hz.

The only way to get Harrys to record data quicker is to get an external Bluetooth GPS with a higher refresh rate and then it will look better because its not skipping all the info in between those seconds.

I have been the apps for autocross, a lot can happen in one second. I have been using DashCommand on my phone, it is more expensive. It records based off the OBDII refresh rate, but does not have the lap features Harrys has. I haven't tried the Rev app just because I saw it hasn't been updated in a long time.