Telemetry system can be as simple as an App on a phone recording using the phone sensors and cameras, up to very fancy systems collecting car data, GPS information, cameras and analysis software. We have been experimenting with various options and here are some options.
The GPS that you find in smartphones only provide 1 data point per second (1Hz) which is pretty inaccurate for any race timing. Using an external bluetooth GPS (5Hz or 10Hz) is the way to go. We experienced the following GPS:
- Garmin GLO (recommended): Combines GPS and GLONASS (russian GPS) systems for a much better accuracy especially in remote areas. Works at 10Hz, great ease of use and battery life.
- QStarZ BT-Q818XT: for less than $80 you get a 1Hz/5Hz/10Hz GPS that works fine in most conditions, GPS accuracy will drop sharply in remote areas (will work ok at the track but not that great for rally or hillclimbs). Make sure you download the software from the QStarZ site to reprogram the 1Hz button to become 5Hz instead.
- QStarZ BT-Q1000eX: a GPS with data logging that works in 5Hz for older models and 10Hz for more recent ones. The memory on the older model is too small on the device and you won't be able to record more than 15 minutes at 10Hz. Newer models can store 400K records (about 11hours at 10Hz). A good option if you don't have a phone and just want GPS data (you will still need a laptop to download and review the data). The accuracy issue will be the same at with the 818XT.
To collect data from your car (like RPM, speed, temp...), you need to connect to the OBD2 plug (diagnostic plug) that is pretty much standard on all cars since 1996. We recommend the ELM 327 Bluetooth OBD2 mini-connector that just costs about $10. Note that this works for most cars and generic engine data, but it won't read car specific error codes like ABS or other internal systems that are not standard (but it's all good for telemetry).
Note to iPhone users, you are out of luck since Apple doesn't have a standard Bluetooth stack and this won't work with iPhone, You will need a Wifi ODB2 or an expensive iPhone compatible ODB2 (sorry for you but you should have bought an Android phone! :D). For more info on iPhone, check this NER iPhone thread.
Telemetry with Android
We have had great success with a very simple Android tablet and some apps for both car telemetry and rally computer.
7" Android tablet with GPS ($50): http://www.amazon.com/gp/product/B015PVT1EO
RAM mounts to secure tablet to rollcage:
rollcage tie ($17): http://www.amazon.com/gp/product/B0030HO6SM
tablet holder ($30): http://www.amazon.com/gp/product/B005MFKV20
ball mount for tablet holder ($7): http://www.amazon.com/gp/product/B004O8LF26
long arm ($18): http://www.amazon.com/gp/product/B000WJA5ZY
Bluetooth OBD2 for telemetry ($7): http://www.amazon.com/Version-Bluetooth-Multi-Language-12Kinds-Android/dp/B00N2K6M2A
Racing / Lap timer:
We recommend RaceChrono (http://racechrono.com/) that you can find directly from Google Play. It can work on a standalone phone/tablet but can also connect to a bluetooth external GPS and external bluetooth OBD2 really easily. The Pro version can also integrate GoPro footage with telemetry overlay (we never used that feature and use RaceRenderer for telemetry overlay in our videos).
Here is an example of what you can do with RaceChrono:
Another option is Trackmaster but it lacks the analysis features of RaceChrono and the bluetooth driver that you have to pay for is pretty unreliable to say the least.
Stage rally copilot app:
Rally tripmeter for stage rally navigator to keep track of time and distances: https://play.google.com/store/apps/details?id=ee.siimplangi.rallytripmeter
All you need from Recce to the stages with easy synchronization to the rally clock.
Car monitoring / diagnostic:
Torque Pro is a great app for OBD2 diagnostic, allows you to pull out the codes if you have a CEL (Check Engine Light) and need to reset them. It can also display gauges with data obtained from your Bluetooth OBD2.