It won't be as loud as an rpi. I'd go test drive an msport. I never drove a regular 550i to compare. Stock exhaust has a flapper valve for sport mode. No flapper on this exhaust so it's probably like sport mode and a tad more sound. I went rpi and picked up some drone then sold it.

It's a slip on.

I've heard an msport drive away and you can tell it's a v8.

 

If your interested let's make a deal. Car has been sold. Need this gone.