[Dinsdale]

SECTON 20: GENERAL REGULATIONS, ENGINE: 1, 1.3 EXHAUST (Page 3)
(2/4/2013)

Exhaust collectors/stacks must be securely fastened (i.e., metal connector
straps, bolted, welded, etc.) to prevent loss of collector/stacks during competition.
Effective Jan. 1, 2014, removable multi-piece exhaust collectors/stacks must be
securely fastened with an NHRA accepted header tether, such as Lokar’s
1400009 or 1401009 to prevent loss of collector/stacks during competition.

So even if the collector is strapped, bolted or welded to prevent loss a teather is still required. Certainly makes a lot of sense to me.....NOT!