I had my exhaust changed over to 4" and the muffler is straight through. I don't mind hearing the whirl of the turbo but I don't like the fluttering/slapping sound it makes on acceleration at all. I want to quieten it down and would like some suggestions on a muffler that will achieve that please.
David

 

I have a E99 that I put an MBRP 4" turbo back with muffler and it was quite enough for me most of the time but my wife loved to complain about it when towing the camper. I recently purchased a 2000 F350 and instead of new exhaust I cut the old muffler out and installed a Walker RV muffler which is straight thru but much longer than the MBRP muffler. I had to bend a 5-1/4" offset because of OEM muffler was not straight thru. I got the muffler from Summit Racing for $48. It is just as quiet as stock and EGT came down 100-150 degrees. It is 3-1/2" which slips over the stock pipe and clamps can be used. Maybe they make one in 4".

 

MBRP may have one. I run an aero turbine AT4040 which is on the louder side but they have a newer AT5050 that would work.

 

Im running an Aero Turbine 3535 (3.5" on stock exhaust). I cant say its loud, you can just hear the whistle and rumble a little more. No drone. I dont really know what it sounds like on the outside though; in the rare occurrence that Im NOT the one driving it, my wife is, and Im in the passenger seat!

Sounds like that Walker might be the thing for you.

 

What muffler do you have now? My Flow Pro does the flutter at acceleration and the drone at 50 MPH.

 

Not sure honestly. I took it to a muffler shop and told them I wanted 4" turbo back exhaust installed. That was the beginning of my mistake. I can say without a doubt I HATE the flutter, but that's just me.
David

 

Subscribing. My 99 F350 cab/chassis needed an exhaust system when I bought it. I installed a 4 in. stainless Magna Flow with a straight through muffler that was too loud. I replaced it with a 4 in. generic truck muffler that isn't much better. I'd love to quiet it down while keeping the EBP low.