To upgrade the performance on any turbo powered car, you need “breating” upgrades. The car needs to inhale better (intake modifications), but also exhale better (exhaust modifications).
The most important component in the exhale process is the downpipe, the first pipe after the turbo. Upgrading this to a larger diameter, will allow for quicker turbo spool, which helps in scavenging but also in building boost.
As a pleasant side effect, the exhaust note will also be more throaty! The S80 has very limited options on paper, but I was able to buy and fit this with help from J&D Auto Onderdelen, who helped me tremendously in the pre-sales process (making sure that everything would fit). I can highly recommend them!
It’s a quite expensive upgrade, but well worth it.
It’s highly recommended to get some new nuts for securing the downpipe.
Old vs new, look into the differences in the diameter of the neck.