Exhaust Disappointment
 

I resently purchased the Banks Monster Split Dual System for my '09 1-ton dually. It has given the truck a much deeper tone but is not what i expected or wanted with regard to sound levels. From reading other threads on this site, I understand the DPF is the issue. But what I haven't found is a good alternative to removing it. Maybe I just havent found that thread yet, so if anyone can point me in the right direction or has advise on the topic it would be appreciated. I have been kicking around experimenting with the straight pipe through the inside of the DPF like i have read about in other threads, but with an additional modification. I would take a 2.5" or 3" schedule 5 stainless steel tube and weld it to spacers on each end that would center the pipe through the filter assembly. It would allow a portion of the exhaust to pass through the center tube offering the benefit of a straight pipe, but would also allow flow through the outer cavity between the O.D. of the inner tube and the I.D. of the DPF. Figuring it would not interfere with the sensor readings. I wouldnt get the full effect of bypassing the filter altogether but would get a noticeable improvement in sound... IN THEORY. I have calculated the effect it would have on the back pressure/flow and it is negligable (yes, i am an engineer... my apologies). But what i dont know is the configuration on the inside of the DPF (i.e. baffles, sensor penetration length, etc.). Thoughts... questions... concerns? I cant be the first one to come up with this idea so any feedback is welcome.

I did a dpf delete and left the rest of the exhuast the same and did not think it changed the sound that much.

Someone I was talkign to suggested something similar, they said a simple pipe routed along the outside (above) the dpf, in and out the same size, so that some of the exhaust can go around the filter might work... Seems like a pita to me but if it works/makes more power and doesn't kick off the dpf codes I'd do it in a heartbeat.

I do not know how exactly the DPF looks on the inside but I would assume there is some sort of material in the DPF system that slows the flow to be "cleaned." by that I mean there is probably some material that covers the whole cross sectional area of the pipe. Like I said I do not know what the DPF looks like on the inside. I am in school for engineering also. The idea would theoretically work but I think the amount of restriction in the area between the open pipe and the DPF wall would screw up the flow when the DPF pipe ends.

I would recommend a chip that shuts off the DPF and a DPF removal. You can get a quote on here for a cheaper chip and DPF removal pipe.

if removing the DPF (assume the resonator was removed as well) didnt change the sound much, what is muffling the exhaust? Typically cummins engines hava a sound all of their own as you know and some are loud enough to hear indoors when they drive by. I am puzzled what is so much different about these late model engines/exhaust systems.

FYI... i also installed a Banks Ram Air System (with scoop) and it does not muffle the sound emitted by the engine brake and turbo nearly as much. Just enough to be noticable but not too much drown out the radio.

we you try to look thru dpf you cant see any light at all. then you got the cat.:s:

i have heard they are awfully expensive to replace though, around 3g;s just for the dpf? is this true?:rocking:

Ok... lets go back to the basic question... will removing or bypassing the DPF make a difference in how loud the exhaust is? does it become so load you cant hear the radio?Ive heard different answers to the pros/cons of removing the DPF.

I got a stright pipe on my 07.5 it is not loud at all. I still can not here it when i drive down the road

I have a 5" straight piped stainless steel dual exhaust from magnaflow... threw off the 5x12" tips and put on 2 6x24" tips. Its about as loud as a 5.9 with a performance muffler. With ALOT more turbo sound imo.