I have a 5.4 4x4 SCrew with Flowmaster 50 series SISO that has a joint to make it a dual exhaust on exit. Got huge stainless tips (4" diameter or so).

Thinking about making the swap to a 40 series Flowmaster. Anyone out there made a swap like this? I really want to have more rumble just off idle like when cruising thru the neighborhood. I don't want to have 'over bearing' noise from the system in the cabin, but generally I love to hear the exhaust note.
The setup now only sounds 'right' when I punch it.

Will I get better sound with bearable cabin exhaust note from the 40 series?

thx,

Brian

 

I have the 50 and it has a good sound. As mine has aged, it seems to be a little lounder. Now when I ease out of an entersection, it has a nice powerfull noise to it (that and the FIPK) and when I really get on her, she loudens up quite a bit. I have never really compared mine to a 40 series, so I dont know what the results will be like if you make the chage. Good luck

 

If you want really loud then the 40 may be what you want, but I think its almost too loud. I would think that it may bug you when driving on the freeway as far as cab noise.

 

tbbr
I had the 40 series si/so on mine and it had the rumble you are looking for and ALSO the cabin drone at 1700rpm(65mph) range. It made it hard to talk going 65 every weekend on trips to VA. I switched to a 50 series si/do coming out the rear and it has a nice rumble to it and no cab resonance like the 40 series had. People hear you moving and if you stomp on it it really sings. Mine seemed to get louder over time to where it is now and it sounds great. This is also on a 5.4 but 2 wd

You might like the 40s roar but my wife and I disliked the cab drone on the highway.