My truck had a dual outlet single inlet Magnaflow turned around making it a dual inlet single outlet. Today I took that off along with the cats and replaced it with a dual 2 1/2 inlet and oulet and ran it to the bumper and dumped it. The inlet side of the muffler is basically the stock 3 inch into the muffler. So I don't know if you would call it a dual 3 inch in and dual 2 1/2 out of what. It sounds good and very little drone so there I am happy, however it seems to have hurt the bottom end a little bit. I did it planning for the motor going in because I thought it would need a good bit of flow. The 02s are turned off but the tune on it was for the previous exhaust. Will it take a little time for the ECU to adapt to the freer flow or does the tune need to be changed? What the previous setup better suited for my goals of killer low end and mid range and this setup better suited for topend? I have some 31lbs injectors on the way and will put them on with the TBSS intake and have the tune changed then I just want to make sure I didn't make the wrong choice. Thanks.

 

I wouldn't think that dual 2.5 outlets would hurt your bottom end. I'm running dual 3" in and a single 4" out with no loss of bottom end. Still have traction problems. and bust loose from a 30 roll.

 

You still have cats and all though. I took mine off and swapped to duals