I have '12 550i (N63 engine) with DINAN stage 4. As I understand, that's is just a single firmware version that is optimized for the presence of their intake and exhaust, with no adjustable parameters.
Suppose I do some other upgrades, e.g. bigger turbos, or I just want to tweak the map to give more boost. What are my options? I'm guessing DINAN must go. I see a few other companies making similar products (ESS, Burger) but it's not clear which one I need. Burger has something called "JB4" which sounds a lot like what I need but I don't see it available for N63 (they do have it for S63 / F10 M5).
And more generally, what are my limitations hp-wise? It looks like S63 can go to 700 hp with stock heads, cam and pistons. (Incidentally, is there any reason why no one seems to bother with cam swaps in BMW world? In LS1/LS3 world, stock cam is pretty much the first thing to go.) Any reason why N63 can't do same? Do I need to upgrade the clutch pack or the torque converter?