6.7L Cummins Forum

Correct.

__________________
CUMMINZ NC
2007.5 CTD, QC-DRW 3500 BFT Laramie, Smarty S-67, AMSOil Dual-Gard Bypass, Custom Line-X 4x4, 4.10LS, 988s, 68rfe, MBRP 5", Mobil Delvac. Yukon free spin, 19.5x245 G647 Goodyear's - 2006 - 37RLTSD Cedar Creek-Day Dreamer
My 2007.5 DRW Truck at www.CumminZ.com

I have found as many posts claiming no increase as there are claiming an increase with the muffler delete setup. I thought the muffler/resonator or whatever we call it had a baffle and was restrictive but was told it was straight through and it was more like a glasspack. I decided to pull the tailpipe off mine to see for myself and here are the pictures. This view is from the tailpipe end. What you see is the thermocouple/temp. sensor and the back end of the DPF, straight through the muffler. My question is how can a muffler delete increase mileage if the muffler is straight through anyway? Does the baffle I see cause turbulence? I am not doubting anyone who claims an increase but how??? I was about to spring for one myself until a found all the claims of no increase. How about a little feedback on this??? mariocand, are you still seeing the 1.7 mpg increase?


Thanks.

Attached Thumbnails

   

My guess is larger diameter pipes which allows for better flow.

__________________

2007.5 Dodge Ram 3500 HD,QC, 6.7L Cummins, 6speed Auto, 4X4, Bighorn Edition.
Click for installs: Carr Steps PML Diff Cover Edge Juice with Attitude Volant Intake Hankook ATM RF10

it is still between 1-2 better. I have to agree with squid 5" instead of 4" flows more. But the original muffler, I would say the baffles create so
e turbulance to quiet the exhaust note at the expense of mpg. Plus there is the perk of the louder sound of the engine and turbo thru it. No drone at highway speeds but noticable difference.

The bends are also not so severe correct?

__________________

2007.5 Dodge Ram 3500 HD,QC, 6.7L Cummins, 6speed Auto, 4X4, Bighorn Edition.
Click for installs: Carr Steps PML Diff Cover Edge Juice with Attitude Volant Intake Hankook ATM RF10

Thanks for the input. I wanted some confirmation before I spent the money. I think I'll go for it. I can see the less severe bends aiding flow and the larger pipe flowing better overall. All the exhaust systems I have installed in the past have totally eliminated restriction be it motorcycle, car, truck or airplane. I haven't had to deal with such a complex exhaust system before. I'll let you know how I come out.
Thanks again.
Have a great day!

That is correct.

__________________
CUMMINZ NC
2007.5 CTD, QC-DRW 3500 BFT Laramie, Smarty S-67, AMSOil Dual-Gard Bypass, Custom Line-X 4x4, 4.10LS, 988s, 68rfe, MBRP 5", Mobil Delvac. Yukon free spin, 19.5x245 G647 Goodyear's - 2006 - 37RLTSD Cedar Creek-Day Dreamer
My 2007.5 DRW Truck at www.CumminZ.com

CumminZ, you pull a 5th wheel...How does the exhaust sound echoing of the 5er??

__________________

7.5 3500QC 6.7CTD 68RFE Build date June 2007
Superchips tuner 3808, Boost/EGT Laser Gauge, Airaid cold intake

Not one bit.

__________________
CUMMINZ NC
2007.5 CTD, QC-DRW 3500 BFT Laramie, Smarty S-67, AMSOil Dual-Gard Bypass, Custom Line-X 4x4, 4.10LS, 988s, 68rfe, MBRP 5", Mobil Delvac. Yukon free spin, 19.5x245 G647 Goodyear's - 2006 - 37RLTSD Cedar Creek-Day Dreamer
My 2007.5 DRW Truck at www.CumminZ.com

Great, are you seeing any MPG gains from towing?

__________________

7.5 3500QC 6.7CTD 68RFE Build date June 2007
Superchips tuner 3808, Boost/EGT Laser Gauge, Airaid cold intake