While the sub-genre of Anti-gravity Racing negates the performance factor of Weight, Mass is still very much a factor in handling on curves, acceleration and top speed. How you load out your craft will, logically and realistically, affect performance. So your craft’s performance will be at the mercy of how much punch you literally pack into it.
Feet Per Second features a unique craft/track integration and movement mechanic, which is not truly Anti-gravity in nature, but Anti-gravity-esque, combining adhesion with impulse. It is therefore natural to revert the traditional Mass factor to Weight(excepting for tracks presented in a zero-G locality), which will effect your craft’s performance adversely and exponentially.
