[RC-Monster Mike]

GIGO as they say (garbage in=garbage out). I would look at the numbers you entered in. The eagletree calculates speed based on rpm, so tire size is a factor in the calculation. If your tires are ballooning or the tire size is improperly calculated, the system will not show an accurate speed. I think you must determine exactly how far the car moves with one revolution (of the magnet-depending on where the magnet is located). My guess is that there is an info input error.