Well, before some kind of acceleration check is available, I'd suggest using MaxSpeedNodes in TCD file. The default ones are for braking zones, and as already mentioned I have some doubts about real usability.
However, creating MaxSpeedNodes at acceleration places should be possible and in fact very effective. For a start, I'd suggest adding the following item to the TCD file, under BL1 and XFG plus XRG plus FBM:
MaxSpeedNodes=0,0|74-80 + 0,0|170-174 + 0,0|208-212 + 0,0|250-254 + 0,0|292-296
The zeroes mean there will be only speed measuring going on, both in 1st and subsequent laps, this all in every major acceleration zone, after chicanes and main turns.
For the speed check to run you need to have CheckMaximumSpeed set to true in SRV file. This check is available only in Airio FULL and PROS version. Also advanced check must be turned on, as shown by !chk.
Entry speed into the zones is measured, so you may move them a bit, maybe. While the zeroes are in effect, the measured speed is stored into log file as a DEBUG message, which means LogDebugs must be active. (I'm not sure now, maybe using !deb admin command also turns the debug logging.)
From logs then maximum speeds could be read and zeroes replaced by kmph data. one catch though... This check runs only during race, because of its primary intention, to prevent crashes. Eh, should be optional...