Net power increase from a turbo back afe mufflerd vs turbo back straight pipe

[mharring]

I got into a arguement with a friend about how my mufflered 4 inch exhasust is holding my truck back. It wasn't really an argument but more of a disagreement!! Ive got a 4 inch AFE atlas ( mufflerd)with there down pipe as well. My friend tells me that the power increase is huge from a 4 to a 5 inch set up. Honestly im looking to go mach 4 in a 7000 ld truck. Im looking for practical and not obscenely loud. Am i wrong to assume a 5inch straight pipe vs 4 inch mufflerd will net me only a minimum gain in hp? Im really about the fuel economy. Im averaging 2000 miles a month. And do they make a 4 inch dump valve if i am wrong? Just thoughts?

 

[mharring]

All most identical sound as mine

http://youtu.be/kiMDm3X2c7k

 

[mharring]

Thats a straight pipie but close

 

[drunk on diesel]

you won't gain ****

your friend is a ****ing idiot

 

[mharring]

He seemed to think that loud equals fast i mean mines loud but its a evil i cant get rid of!! Im sure there are much louder but i cant deal with it!!

 

[Fordguy100]

Unless you are pushing crazy power levels, 4" vs 5" will be (nearly) identical power-wise.

 

[Rubenk]

I gained zero going from factory catback with muffler to open downpipe on the drag strip.

I have 4" SDP downpipe, dp-f/doc derete pipe, and rest factory exhaust. Made a pass down the strip, then next pass was open down pipe and no significant change.