Hi all,sorry if this has been covered a few times!!
My query is regarding speedo calibration,I'm fitting the magnets to the prop on my BEC which is no problem as with mounting the sensor but how do I know what calculation I require for setting the unit,also having just bought the car I have no idea what the diff ratio is ??
Cheers Craig

start with the magic number 520
and use your tomtom to ad or take away.
use six magnets on the prop adapter 15 inch wheels