Does the 531 really need the Supertrapp disc exhaust stack?

[Falstaff]

I struggled with getting my first 531 running until i figured out that the Supertrapp disc/exhaust tuning diffuser was hopelessly plugged with oil and carbon. My experience with Supertrapp exhaust systems was with 4 stroke dirtbikes where you could tune the bike by adding or removing discs from the exhaust pipe outlet (increasing or reducing back pressure). Why did Dewey add that to the pipe? Mine seemsto run fine without it. Why would you want to add restriction to a diesel motor?

 

[Chainbreaker]

Perhaps as a way to help quiet the exhaust note a bit?

 

[Dieselmeister]

They are supposed to be spark arresters for what its worth. I added #10 stainless lock washers between each disk, and eliminated the back pressure problem, while keeping the original "look".