Originally Posted by mjacquesjr (Post 656330)

General Regulations Section 21, page 19
General Regulations
Requirements) is permitted. Removable weight must be securely
mounted to the frame or frame structure by a minimum of two
1/2-inch-diameter steel bolts per 100 pounds, or one 3/8-inch
steel bolt per 5 pounds; all other weight bars, pucks, etc. must
use minimum 1/2-inch-diameter SAE grade 8 bolts for attachment.
Hose clamps, wire, strapping, tape, tie wraps, etc. for securing
weight or ballast prohibited. Acceptable forms of ballast are 1)
Heavier gauge steel floors (i.e., 16- or 18-gauge, heavier gauge
and/or plate steel prohibited); 2) Frame reinforcing cross members;
or 3) the addition of protective equipment such as roll bars,
flywheel shield, etc. If additional ballast is needed and is permitted
by Class Requirements, it must be permanently attached to frame,
bolted with two 1/2-inch-diameter bolts per 100 pounds, with nuts
welded to bolts. Maximum amount of removable and/or permanent
ballast, unless otherwise stated under Class Requirements, is 500
pounds. Cars running 8.49 and quicker are limited to 250 pounds
maximum, per SFI chassis specification.

Originally Posted by Andy Friar (Post 656355)

Seems counter intuitive that welding a nut to a bolt, which then makes both more brittle in that area, is the rules solution. If this acceptable for weight boxes, they why do collectors need tethers and not just welded bolts to nuts? Why is there not any, or very minimal rules, about how to mount an aftermarket race seat? I weight 275#, so I am 3, 1/2" bolts worth. I might be using logic and thinking too much though...:D

Originally Posted by west coast (Post 656375)

Best place for ballast is at the end of the track, waiting for you to it pick up.