Howdy and welcome to the Forum
I initially did the Gilomen clutch kit and ECU tune on my Xpedition, but I’ve since swapped the clutch kit over to Aftermarket Assassins. AA has 2 options for the helix, Performance and High Load, and I couldn’t get the Gilomen clutch kit to dial in quite right. AA also has the Buttershift washers, and billet primary cover plate that helps prevent the primary towers from spreading and increases air flow through the clutches.
To me, the ECU tune and clutch kit is a must! Polaris has dumbed down the performance extremely bad with the comfort clutch and it never really helped the noise levels.
For sound dampening, there’s things like DKZ or CRC foam panel kits that can help a little, and isn’t too difficult. However, for real results, it takes a lot more work. I posted the process we do for sound dampening and insulation here:
Thread 'Xpedition XP5 insulation job.'
We’ve got around a 9db noise drop, while still boosting the rpms and performance with a clutch kit and ECU tune.
Another “must” is having your suspension adjusted. In the 20+ Xpeditions I’ve worked on, precisely 0 of them have come from the factory at the proper ride height. Also in that many, around 8 shocks have had the proper nitrogen pressure. While these Xpeditions ride really well, straight from the factory, there’s a lot of improvement to be had by dialing in the suspension.