Track analytics - what do you use?

[CP 1///M]

Wanted to start a thread, and here is my setup and some comments on what I find:

GoPro Hero 3+ mounted in between the seats (around head rest height, Medium perspective to capture full steering movement + shifting), Wifi controlled by M Laptimer, with RaceChrono paired with Dual XGPS160 (10Hz) current for quick comparison with track buddies (as they all run RaceChrono)

After taking a hiatus from my data extract scripts from M Laptimer, I was doing some analysis and wonder if I might have to go RaceChrono Pro entirely using an OBD-II dongle (most likely OBDLink LX Bluetooth since I run RaceChrono on Android)

Currently, almost all the data returned by M Laptimer runs at about 1Hz on average, except for GPS Location where the car seems to interpolate internally based on all the data it has (iDrive Navi + Speed + Steering angle) to give a 10Hz stream that is somewhat aligned (rather than a best effort 1Hz stream on other data). Occasionally, I will get an extra file that contains 10Hz stream for both Lateral and Acceleration Gs - I do not know how this is triggered as it's not consistently there from each recorded track session

The main advantage with M Laptimer is that it can now control a single GoPro camera at the same time which makes it far easier to synchronize the data streams for post processing (using DashWare, the latest version can now generate a transparent image sequence that you can import into your own video editor). The problem is the relatively low frequency of all the data besides GPS location and acceleration

RaceChrono will pair up with an OBD-II adapter to have an integrated stream just like M Laptimer, except for video (Pro version can record right on the phone). Not sure what the CANbus frequency is for car telemetry even though OBDLink LX claims to do up to 50Hz (looks to be in total, so if you have 5 variables to collect it will be effectively 10Hz each)

The other option I found is the M Performance Analyzer (availability is uncertain from BMW), which uses its own OBD-II dongle and app (written by a 3rd party) to generate the same thing right on the phone (possibly at the time of recording since you "build" the gauge overlay ahead it seems)

Of course, if you really want crazy telemetry you probably go VBox but that's much more $$$ - I don't think for my occasional track days I would go for that. And even for the OBD-II dongle, I wonder if something like the Carly Gen2 would work with RaceChrono (which might give me the flexibility if I wanted coding capability - although that's another $60-80 on top of the dongle)

Do any of you use anything? Or am I the rare bunch that records video and try to put telemetry overlay for a track day?

[ayao]

Try looking here in the M3 track forum. Lots of active discussion:
http://www.m3post.com/forums/showthr...m#post21939839

[Amnizu]

I use the aim solo dl with a go pro for video. When I feel like I need to have data overlaid I use race render. Generally the data available in the solo DL is fine without the video as I'm looking to understand where I can gain / lose time. If need be I can go to my video for a lap and compare them side by side for line.

I highly recommend the solo dl. I have used Harry's lap timer with an external gps. It works and is cheaper but it can be a real pain to get working.

[Tinsta]

Vbox sport is a smaller device which can bluetooth to your iphone and data can then be loaded into a laptop with the vbox software to analyse further.. no video though, but captures everything else.

Pretty cool

[BimmerAg]

I use RaceChrono Pro. I was a little disappointed with the GPS accuracy and lag from my most recent track day, but that's more likely due to my phone than the app. Everything else is very straightforward and I have been happy with it so far. I will likely get an external GPS and bluetooth OBD adapter in the future.

Here's a video overlay from my last track day using RaceChrono Pro:

EDIT: I also used the same app for an autocross event this past weekend and the GPS data was much more accurate. It was very interesting to look at runs where I would carry more speed through one turn, but hurt the next segment compared to sacrificing speed through the turn but going faster through the next segment.