have it remapped LIVE but ffs please dont get a tuningbox. thats the worst way to get the most out of a diesel.
YES it WILL get the most out of it, but alot of times even more then it can take and i dont think u want to end up with a fried engine.
what tuningboxes actually do is lie to ur ecu so for example they say the turbo pressure is not high enuff so the ecu will increase it.
but there are alot of risks like less say u put a tuningbox and it gives u 55 xtra hp but when u have a problem and ur engine goes in emergency mode it will only have 60hp(just picked a number here) instead of 150 so that ur engine wont be dmg'd. well then the tuningbox will make ur ecu think u only have 5hp so it will still give u the xtra 55 hp meaning u will be driving around with 115hp instead of 60 and that can result in serious engine dmg.
I live in a diesel country called belgium and our top remappers do not give the engine more then 195hp and 420nm torque(the clutch cant take much more). And even then... not every engine is the same... some will be safely tuned at 185hp, some at 195. So dont go over that and u will be fine if u service it regurlary and always make sure its warm before u put ur foot down. Oh yeah if u have used all of your horses then its best to let the car in tickover for a few mins so that ur turbo can be cooled before stopping the engine.