NHRA 2012

Quote:

6:2 UPHOLSTERY, SEATS
The driver’s seat of any car in competition must be constructed, braced, mounted, and upholstered to provide full back and shoulder support. The driver’s seat must be supported on the bottom and back by the frame or crossmember. Except as noted in SFI Specifications, seats must be bolted with four bolts (and nuts and washers) on the bottom and one bolt in the rear into crossbar; all bolts must go into frame or crossbraces. Ball-lock pins for seat attachment prohibited in all classes.



I do not see any minimum size requirement for a seat cross bar but there must be at least 5 mounting points (4 at the bottom and 1 to the crossbar).