Up until this true race car build I have been using my Android smart phone as my source for data acquisition.  The Race Chrono app, paired with an external Bluetooth GPS, has been a great tool, especially for the price.  However, with a dedicated race car, I wanted a dedicated system.

I had picked up a lightly used AiM MXL Pista dash logger from eBay back when I was gathering parts for the E36 GTS build.  At the time I was debating between the AiM and Racepack loggers, ultimately settling on the AiM due to their widespread use at the club racing level of competition.  Having a highly adopted system means it’s easier to get data from other drivers for comparison as well as troubleshooting the system.

The MXL is the previous generation of dash loggers, so the prices were reasonable with the new MXL2/MXS/MXG now on the market.  It still does nearly everything I could ask of it.  It provides a LCD display of all the critical information I choose (temps, pressures, speed, revs, shift lights) and alarms for when user set thresholds are exceeded.  It also provides lapping info, including forecasted (or predicted) lap times.

Spec E46 AiM MXL Installed
The other nice thing about the MXL paired with a modern CANbus car is that it can pull almost any available information that the car is already reading.  So RPM, fuel level, temps, steering angle, TPS, etc are already ready to record.  Additional analog inputs allowed me to add standalone sensors for brake pressure, oil temperature, oil pressure, fuel pressure, and differential temperature.

AiM Oil and Fuel Pressure AiM Brake Pressure Sensor

The MXL essentially replaces the stock dash in the Spec E46, so I mounted in directly to the steering column, just behind the steering wheel.  I used some scrap carbon fiber sheet to fabricate a simple mount that is secured using the two screws that hold the wiper and lighting stalks.  The wiring harness run from the back of the MXL to behind the dash where it splits to the analog sensors, power/ground, and the CANbus.  I added a 4-port CAN expansion so that the GPS, Smarty Cam, and a Memory Key could be added.

SpecE46_IMAG2848 SpecE46_IMAG2842

The other aspect of data acquisition is getting video of your laps.  I’ve been using GoPros for this, but it’s a constant hassle.  The batteries don’t last long, their WiFi remote is very temperamental, and you don’t have any ability for automatic start and stop.  While the video is high quality in resolution and color terms, it’s not very good for the race environment.  The rolling shutter sensor means you get a wavy jello effect of objects in the distance (clouds are the most obvious.)  The other, perhaps most frustrating, negative of using the GoPro is that to truly use the video for driver improvement means hours of post production editing to actually produce a helpful video.

The solution to this is the AiM SmartyCam HD, a truly purpose built motorsports camera.  The price is certainly way above the GoPro, but time and frustrations saved has made it worth it.  The camera interfaces with the AiM MXL dash for both additional data (including GPS) but also means its internal battery is charged by the car and it starts and stops automatically.  It’s pretty much a set it and forget it driver tool.  The raw video is 720p, so not as high def as the GoPros, but the CMOS sensor eliminates the wavy effect and it has light metering functions and stabilization tailored to use in a car.  The end result is actually better video than you can get from any GoPro (for the purpose of in car video.)

The other nice thing about the SmartyCam is that it overlays data on the video in real time.  Speed, lap times, revs, brake pressure, throttle position, temps and pressures are all automatically displayed on the video.  The gauges and graphics are fairly canned when compared to what is possible with RaceRender or Dashware, but it is also much easier to use and saves hours of time.  Because everything is automated means you can simply pull the SD card at the end of a session and have instant feedback from viewing on a laptop.

Another form of data acquisition is the on-board transponder that is required by most racing organizers for timing and scoring.  MyLaps (formerly AMB) has a solid monopoly on this market, so that’s what I ended up purchasing.  It’s a fairly simple system and install.  The physical transponder device is mounted near the front of the car and must be less than 2 feet above the road surface.  I made a simple aluminum mount out of some scrap sheet, which was then riveted to the right frame horn.  Four small rivet nuts then allowed me to bolt the transponder to this mount.  The cable from the transponder runs up through an existing hole in the passenger footwell to the center stack of the dash.  That’s where the “key” resides and power and ground functions are split off.  I integrated the power into the switch panel so the transponder could be switched on and off.

Transponder and Key MyLaps Transponder InstalledMyLaps Transponder Installed


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