The cat-back exhaust system will be made from 3-1/2” titanium tube. Each side has a 4.6” OD round muffler that flows into two 90° tight radius elbows and a 6” x 9” oval muffler. I designed brackets to connect the mufflers and had SendCutSend laser cut them from 0.187" Grade 5 titanium. They have good pricing, but titanium isn’t cheap and four of them cost $310.72. As is typical, I 3D printed a pair to ensure fitment before pressing the order button.
3D-printed tack-welding supports and titanium brackets
Mufflers and brackets being tacked. Note that the 3D-printed supports under the round muffler (center bottom of picture) perfectly aligns the mufflers and prevents the round muffler from rolling.
Excellent muffler/bracket fit
Once the brackets were tacked the elbows were tacked
Left-side mufflers manually held in place
The next step is to fabricate a frame from 1/2” OD 4130 tube to support the mufflers and the bumper. Once that’s done there will be a lot of pie cuts to connect to the catalytic converter and the x-pipe.