After my 1995 XJR / US version had noticeable slowed down and started making noises, my mechanic found the supercharger (Eaton M90) to be the culprit and I got it replaced with a used one.
Car is clearly faster again, but I miss the very noticeable acceleration boost (you could hear it too) when the gas pedal is fully floored. Which was always very helpful during overtaking. For example, the car needed only 6.5sec from 0 to 100kmh.
This is now missing. What could it be?