dieselcamp

Straight pipe. I left the resonator on no drone with BAHF, the turbo whistle quiets down the exhaust to eliminate drone, toss the silencer ring as well. Straight conversion $ 40.00 I think it was for 3 feet pipe a reducer and clamps. BAHF cost of filter, my heatshield alluminium checker plate was free, got added HP on low end and better mileage.

collin_bucko

Straight pipe from the Cat back, $40-50 in piping, and toss out the silencer ring on the turbo. The 24 Valve cummins is loud enough at stock to wake your neighbors, so you might as well go with whats fun!! Better fuel mileage, and some good low end grunt.

quicksilvr

Any opinions on what produces the loudest cummins grunt noise, 4 or 5 inch? Or in other words does the 5" sound "airy" or "hollow" when compared to a 4" system?

collin_bucko

A 5" will have a lower tone, and will "bellow" more just because the sound has more area to bounce around inside the piping, wheareas a 4" will have more of a higher pitched turbo whine, but the turbo whine will be as loud as the 5"

rage_blue

4 inch exhust gives you more power than 5 inch. Unless your running 600 or more horse. 5 inch is big enough to create pulses as the gasses expand thus reducing flow. And I'm on the MBRB wagon. Although AFE has some exhuast out thats really cheap, stainless is the same price as mbrps aluminized, But it doesn't sound as good and they don't install as nice. Nether one reqires welding.