Second photo the internal stinger. It's an @ 8" piece of thinwall SS tubing, .500" O.D. & .437" I.D.
To get O.D. to fit into the pipes stinger, a piece of silicone tubing was slipped over tube & sanded down by belt sander to @ ..010" bigger than stinger & pressed into place leaving @ 1/2" hanging out. A 3/16" drain hole was drilled into tube so water can be drained from pipe if dunked.
Tube once into position puts end of internal stinger right at the Max diameter of pipe (basicly at weld seam of cones)
Third photo showing internal stinger pressed in. A single "steel" 1/8 pop rivet set to prevent it from coming out.
Forth photo, one of Mike Tysons EXCELLENT mufflers attached to stinger. Should be a sub 85DBa set up
Last shot showing the Chinese WTC pipe next to a NFS 1" band pipe. The china pipe is a BIG volume unit for sure.