Ok, apparently I missed this one yesterday. As an oil-burner junkie, I may be able to help ya on this one. The long and short answer is: you can't blow black smoke AND keep your warranty, sad to say, but smokin' requires some major modification to you fuel AND emissions system both of which will void your drivetrain warranty.
Black smoke is caused by an over fueling of the compression chamber, basically the smoke is poorly burned diesel fuel and while it DOES look awesome when you mash the skinny pedal, it means you're blowing money out your tailpipe. Now, if you keep your stock emissions system and over fuel, you will clog your DPF in no-time, and no matter how many cleaning burns you do, it will clog up and you'll have to see your dealer to have a new DPF replaced... and they will wonder why it happens so regularly with you, and a smart tech may start looking.
Now, the turbo-back systems have the lovely DPF-delete pipe, which, based entierly on your local laws, can be a good thing or not. If you live somewhere with strict emissions controls on diesels, then a DPF delete will be the bane of your existence, but if you're somewhere that doesn't do any diesel emissions testing then you're in the clear... just don't travel in the truck to states WITH testing or you either get ticketed or impounded for messing with FEDERAL emissions requirements. Now, being in Alberta
I ahve no emissions requirements at all, so DPF deletes are common, in a lot of states it is illegal and strictly enforced.
Now, if you want to make serious power from the 6.7L's larger displacement and are willing to throw your drivetrain warranty out the window, then there is SO
much you can do, ported injectors, higher pressure/flow fuel pump, air/fuel separator, turbo-back exhaust system (can we say stacks
), tuner with DPF delete capability (I recommend H&S miniMAXX or BlackMAXX), and once you ahve your fuel/exhaust system sorted out, then a large single turbo or compound turbos to get the A/F mix right.
Any more questions, feel free to ask, can you tell I love compression combustion engines? I just wish I had a cummins