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      05-08-2013, 02:17 AM   #34
regular guy
Lieutenant Colonel

Drives: Sprint car
Join Date: May 2013
Location: California

iTrader: (0)

We have the ability to read the GPS speed at the same time as reading the BMW speedo directly from the CAN bus. Here's the data we collected during a race a few months ago. It looks like the speedo error is greatest at low speeds, and it looks like it stabilizes to about 3.0 - 3.5 % error. Keep in mind this is only one race, and only goes up to 155 MPH. Vehicle was E92 M3. Speed is on both X and Y axis.
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