Initially, Laptimer (and it's video recordings) displayed speed readings almost identical to those shown on my headunit's display (Kenwood DNX7240BT, with Garmin sat-nav.) Despite slight lags, during acceleration, my iPhone 4 and, later on 4S,
matched with my sat-nav's speedo. So, the built-in GPS is acceptable until I purchase an XGPS150E.
As recommended, by your good self, I obtained and fitted a GoPoint BT1, last year.
Immediately after uploading several clips to YouTube, following a trackday, friends commented that they liked the added OBDII data but asked what had happened to the iPhone's speedo. It looked to be clearly under-reading, throughout the clips. I then took my first look at the clips and agreed.
Since fitting the BT1, the problem has continued, even with my iPhone 5. [Yes, Harry, your excellent app. has been the main reason behind upgrading my phone twice in the last 12 months
At least I now have an iPhone 5 with 64GB 
]I've tried changing between mph and Kmh in Laptimer and, via it's supplied app., in the BT1 itself.I have also tried changing between calculated and measured speeds in Laptimer. All to no avail, the speed displays too low a reading in either setting.
As my car is an Evo Wagon, every single one was made strictly for sale in the Japanese market only. Upon import to the UK, an adapter/converter was fitted to the gearbox, changing the car's speedometer to read in mph instead of Kmh. I believe this convertor to be the same type as almost every JDM Mitsubishi received upon arrival.
Is it possible to make a change in my settings so that Laptimer modifies the received OBD data to compensate for the artificially reduced signal/pulse ? If so, please advise.
If not, is it possible to retain OBD data but exclude its given data, regarding speed, in favour of obtaining such from GPS instead ?
Cheers,
Andy
