[Mistoffeles]

It's not like I am asking whether to go 2:1 or not, I never asked that. I am only asking whether I absolutely need mufflers, resonators *and* pre-cats on each pipe. I only ever had a cat and muffler on my X1/9, and you can bet your sweet posterior it benefitted from a dual exhaust conversion when I had the boost pressure jacked up to 17:1 (with a lot of intake changes). There was never any question about whether I would or would not have a complete dual exhaust or why, just what I really, absolutely need, now that I don't have the help of a crazy Renault mechanic.