Living in Stockholm Sweden I visited one of the absolute best turbo shops here (Turbocenter in Tumba - just outside of Stockholm).
It's a Company, specilizes in turbos since early nineties and these guys have broad experience of the Bosch ECU system.
I also got graphs from the bench of the performance of the car Before/after.
I gained 37 hp and 50-someting Nm in torque.
Actually, these gains are not the significant numbers. What's impressive is the rpm range of higher Power which I have now...it's damn Amazing!
If I remember correctly, I had 320 Nm (peak torque) at 2400 rpm and then it slowly decreased.
Now I have 372 Nm from 2500 rpm and onwards until 4100 rpm. I'm hitting my "old" peak of 320 Nm at 4800 rpm.
It's simply Amazing how the car has been transformed.
GOODYEAR "Get there"
BMW 520d Sedan 184hp @ 215hp -11-
Alfa Romeo Apider 1,8 TBI @ XXXhp -11-