My dad had a stock 6.7 and it would smoke enought to tell it was smoking under a heavy load.

 

I have also heard that with the new VGT option on the ME14 version that if you switch up to VGT level 4 it generates a larger belch of smoke out of the hole..haven't tried it yet...but just a rumor.....

 

I've found quite the opposite to be true. VGT4 spools the turbo very quickly which cleans it up in a hurry. On SW9 with everything set at 2, and the VGT set on 2 or 3, I get a bigger cloud loading it in 4th gear and then gettin' on it.