Donaldson 4in muffler

[markdixon]

I installed my new Donaldson M085171 and have a few questions. Mainly, as I look in the muffler I see the pipe with the holes comes to an "X" and kind of forces the air to the out side chamber of the muffler. I didn't know if that was the way that all of them are or if thay had redesigned the muffler. Has any one ever tried to open the "X" part of the muffler to let the exaust flow straight through? I replaced my Auto Jet muffler, it was a 4 inch chambered muffler. It was like having the stock muffler on the truck; very quiet. The Donaldson has a good deep sound until about 1800rpm and then it becomes quieter in the cab than the other muffler. This can also be the result of moving the muffler forward. Either way to me the Donaldson is a good bang for the buck!

 

[Shooter]

That muffler has been used for years with exellent results. The ex is quiter towing than unloaded.