280se exhaust replacement

[floyd111]

For once, I am in the right country, in regards to sourcing a stainless exhaust for this car. It can be custom-made in numerous places, and affordably so.
But, what would be the things to look out for, in order to not impact compression or engine performance in general?
Do I need a catalyst or can I simply skip it? (ignore the law for now)
Any important advise here?

[oversize]

If labour is cheap and material cost is reasonable I'd be making a nice set of custom extractors in an equal-ish length and appropriately paired before the main collector (Interference or Tri-Y).  Tuned length headers are easier to make but a more suited to racing and low down torque will suffer.  Unless the car has some sort of local compliance plate I'd not refit the cat(alist).  If you have the original cat it'll be almost blocked by now anyway.  If you have no choice but to refit a cat, you can buy high flow aftermarket ones that will suit your application

[floyd111]

So, you are basically saying: make an equal copy and never mind the cat!
Point taken.

[oversize]

If you mean copy an AMG design, I'd say yes. Throw the cat in the bin

[floyd111]

Actually, that's not what I meant, haha! I have not heard of AMG have pipes for a W116 280.
No, I was thinking of a copy of the OEM system. Take it down, measure it up, recreate in stainless with generic-type chambers. -without cat.