What is the requirement on mounting a seat in my Super Pro racecar?

Answer:

In the 2016 NHRA Rulebook section 20 page 31of the General Regulations it reads “The driver’s seat must be supported on the bottom and back by the frame or crossmember.  Except as noted in SFI Specifications, seat must be bolted with four bolts (and nuts and washers) on the bottom and one bolt in the rear into the crossbar; all bolts must go into frame or cross braces.”