That and all the new sound proofing, hell even the batteries are wraped for sound, I been comparing my 05 to my cousins 07 under the hood, I stick to my 05 to much junk under the hood to have trouble with, but it is quiet, but then I don't want to sound like a gasser

 

the quietness of the engine comes in mostly due to the injectors. . .before the HPCR engines the injectors would only fire once. . .now they fire 3 times per stroke, mostly to quiet things down. the 07.5 6.7L's fire 5 times per stroke I believe lending to a more quiet running engine.

one other thing the cummins crew found is the pilot injection( that is the reason the engine is as quiet as it is) also gave the engine more power while useing less fuel

 

hey drew so how can i wake up this monster

 

Also, didn't they increase the pressure at the injectors to cut down on the Cummins "clatter" or "rattle" or whatever you want to call it?

 

does anybody know what i can do to make my 6.7 louder without removing the dpf

 

Wow, I am surprises this thread got this far without telling him the real problem. Its the DPF dude. mine has it, I have the MBRP 4 inch Cool Duals with Muffler Delete, and it is still quiet.

24ssm- Not currently. The only thing available at the time that can be done without causing some sort of problem with the emissions crap is intake and Exhaust. The May or June Diesel Power Magazine has an article on an "Off Road Only" 6.7 build, but they did not cover the DPF removal, or whether or not there are any codes thrown. Basically, we are f*cked. Shoulda got an 06.

 

Trade it in for a 5.9