TYGA
2.8cm = diameter at exhaust port outlet
51cm = left header length
47cm = right header length
3.5cm= diameter after merge
4.25cm = diameter just before muffler
Tyga has very nice design from 409-stainless. It uses separate header flange that has small enough pipe to fit into exhaust port since header-pipe is just bit too large to fit into 2.75cm ID of exhaust port. Very smooth merge collector going into mid-pipe diameter of only 1.6x larger cross-section than header. This may pose slight restriction in order to keep velocity high. Expanding into 4.25cm section at end before going into muffler with nice transition cone. Has bung for wideband-O2 for datalogging and tuning.