Originally Posted by sleepless
The iPhone's GPS module is mostly useless for motorsports. It needs to be on the dash with a good line of sight to the GPS satellites to have a prayer of being even modestly useful. So, yeah, keeping it in the cubby will not work and yes, a good external GPS module is pretty much a requirement once you get past novice/intermediate driving speeds.
Thanks dude... Was really throwing me off... Every lap was a 2:53/54 lap for me on the Harry's, but the one lap I timed on video had me at 2:50 so was like WTF... This clears things up and looks like a simple fix