[Nonfractal]

LSC mandates 1mm ground clearance for all points scoring cars. (Those classes  that  contribute to the championship)
A new rule for the 2022 season.
However, this is measured under the motor, not the guide, chassis or overhanging body/spoiler.

After all, it's the motor's :
 -  flux leakage that provides the most gain if set close to the track (if the track rails are ferrous) 
 -  steel can which shorts out the rails damaging power supplies.

The scutineering Process is done with plastic  1mm shim under the motor on a clear perspex block.
If there is daylight under either of the rear wheels, that's a "fail".

DiSCA use a similar methodology but use an engineered steel shim that sticks to the motor for scrutineering.

NWSCC doesn't use a shim and has no min ride height rule. 
Those who go too far eventually realise that a car dragging it's underbelly on the rails is not a fast car.


AlanW