-the exhaust is 90% complete…”bundles of snakes” & large Borla mufflers are done. The mufflers took a 2 fitments to get just right; I was trying to balance clearance between the transmission as well as body work. The GT40 is extremely low, and the back of the body is even lower…so it make clearances very tight.
-Mufflers: I went w/ the Borla mufflers as they were 4″ inlet/exits, which matched the collector. They are straight through, and have the sound absorbing materials around the outside…which also helps to keep the outer skin cooler.
-Exhaust Valves: I picked up a set of 4″ QTP valves that are electronically controlled. The plan is that I’ll take ~1/4″ off the outer circumference of the butterfly plates; I’ll run the valves closed for leaving my neighborhood and any other time I need it quiet…then the rest of the time the valves will be open.
-Turn-down tips…this is the 2nd part that I still need to design. It sounds easy, but it needs to channel the exhaust through the center body exit, both when the body is on, and when it’s open as I want to be able to run the engine with the rear clam shell propped up.

The early positioning of the mufflers…this ended up being 1/2″ too high, as it interfered w/ the rear clam shell. the exhaust tips as shown are now cut off, and waiting for the final routing.
header collectors…drilled the holes for the O2 sensor, and using a de-burring tool to ensure a clean weld/install