Replace those tie wraps with these spring clamps that maintain continuous tightening on your coupler. Pliers spread these to about 1 1/2 inches and close to 1 1/8 inch.  Use these on couplers with about 7/8 Header OD or they work well with Header coupler on tuned pipe side where 3/4 size header telescopes into tuned pipe.  Makes your material last longer and makes for a tight coupler to header/pipe contact.  The result is not letting exhaust gases to leak, thereby maintaing good horespower.  These are far superior to ones you might find at McMaster and are much more user friendly.