Dual vs Qstarz vs RaceBox Mini

I'm looking to upgrade from my Garmin GLO GPS (it seems my data isn't as smooth/accurate as it used to be).

My primary concern is data accuracy, which makes me lean towards the RaceBox Mini since it apparently has 25Hz GPS. I also noticed it has a built-in accelerometer, which can help justify the higher price.

Is the built-in accelerometer on the RaceBox Mini any good and/or should it be better than the internal accelerometer on my phone? (Galaxy S22)

Is the 25Hz GPS as accurate as it sounds?

Otherwise, what's the next best option for GPS?

Side note, I thought I saw one of TImurr's posts where he pulled in pretty accurate accelerometer data from the canbus. I'm also considering the OBDLink MX+, which I believe can get canbus data, which would give me another option for accelerometer data.

Comments

  • edited August 2
    If you want best possible accuracy (and/or a proper IMU) buy RaceBox Mini, if you want offline recording (no phone with you), get Qstarz BL-1000GT.
  • If you can get lateral and longitudinal acceleration through CAN-Bus, then you will not really need IMU on the GPS, as lateral and longitudinal acceleration channels are probably all you need from IMU on a car. Also on motorbikes with cornering ABS, you can often get the lean and pitch angles through the CAN-Bus.
  • Awesome, thanks so much for the info! Is the can bus data or racebox more accurate for imu data?
  • CAN-Bus data is better as it's perfectly aligned to the axis (axes?) of the car. Also your car probably has better IMU than the RaceBox Mini. That said, the RaceBox Mini GPS is excellent.
  • Also, in order for an IMU to record correct values, it should be placed as close as possible to the center of mass of the car. In case of a GPS+IMU device, you typically have to pick between good GPS signal or good IMU placement.

    The car's onboard IMU is likely already placed in a more appropriate spot.

    I did a side-by-side comparison of acceleration data from RaceBox Mini GPS (calculated by RaceChrono), the RaceBox Mini's IMU, and my car's onboard IMU (Toyota GR86).
    Both IMUs were equally noisy (or are those the suspension oscillations?!).
    With some squint-based filtering, the data from the car's onboard IMU aligned well with the acceleration data calculated from GPS data.
    Whereas the longitudinal acceleration of the RaceBox Mini's IMU was significantly off both.
  • edited September 16
    I received my Racebox Mini two weeks ago and did some acceleration tests with it last week, in a 7.6sec and 8.5sec quartermile dragrace cars in Finland. Worked flawlessly at 25Hz and the comparison of X acceleration (from internal sensor) vs calculated longitud acc are amazingly close! Bit of difference in peak acc G at start but otherwise very well aligned.

    I did a manual 5 point rolling average filter in Excel to the X acceleration data (from internal sensor) to reduce noise.

    From the 7.6sec 1/4 mile car :
    0-100kph 1.5sec
    0-200kph 3.8sec
    0-250kph 5.5sec
    0-288kph 7.5sec
  • edited September 28
    @pavver Any chance of sending this data to team RaceChrono? It would be for purely development purposes. It's not often I see data from something this fast. Email to tracks(at)racechrono.com if you want to share. :)
  • @pavver nothing constructive to add, but DAMN you haulin!
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