Yes, as Loren said, an OBDII is required, In my case an OBDII plug that transmits the data by Bluetooth to the phone with an app called Track Addict. The phone acts as the controller and central hub that collects the video and GPS from the cellphone as well as the OBDII data in a format that can later be edited on your computer with Track Addict's sister program Race Render. Track Addict can also sync with an external Go Pro camera by wifi, but it seems to really kill the battery life. I'm still experimenting and will try hooking up a power cable to the camera for the next event.
However, without the OBDII, you can still capture speed, the "G" meter and the track map from your phone's GPS. Speed will probably be a bit laggy vs the OBDII but it's worth a try.
Again as Loren mentioned you can get much better GPS data with an external GPS unit transmitting to the app via Bluetooth or wifi, but these are between $80 to $120 from what I've seen so it's quite a commitment. Certainly worth trying your phone's GPS first and see what results you get.
On the other hand it's another rabbit hole to go down that can be a distraction from the focus required during your runs. I'm sure I will soon end up with a 'set it and forget it ' location where it's one less thing to think about
Good luck!
Dan
