Following the amendment to the Exhaust rule in General Regulations, the National Hot Rod Association’s Technical Department would like to clear up some confusion regarding the requirement of the NHRA-accepted header tethers.  If you have a vehicle that has removable multi-piece exhaust collectors/stacks, you must secure them using one of the following methods:

·         Secure the collectors/stacks with an NHRA-accepted header tether.

·         Secure the collectors/stacks with a minimum ½” (half-inch) stitch weld located on each primary tube.

·         Secure the collectors/stacks by permanently attaching them to the vehicle body or frame with positive fasteners such that they require tools for removal.

Please keep in mind that the attachment methods listed above are meant to be a secondary method of attachment.  All factory attachments, such as springs and/or bolts, must remain in place. 

Also, we have had several questions concerning the lack of manufacturer’s markings on the band clamps of NHRA-accepted header tethers.  For the initial manufacturers this was not a requirement; however, all header tether manufacturers are now required to have all components marked with the manufacturer’s name and/or logo.  The initial header tethers that are missing markings will still be accepted by the NHRA.

We hope that this clarification will clear up any questions about the rule amendment; however, should you have any additional questions, please feel free to contact the Technical Department.