More an observation really.
Most TD4s I have driven give the turbo spool whine at about 1750rpm.

Now my Sport, being the quickest and most responsive TD4 I have ever driven (and I have driven loads) lets out a whine at 1750rpm and then another lesser one at around 2750rpm.

Any ideas ??
I'm thinking remap but don't know how these affect boost.

Did the sport have a different map on the ECU from factory?

Everything I read says no, but you want to try it !!