a 6. 7 dyno after a dpf delete was put on it gained 85ftlbs at the rear wheels. that filter is chokeding that truck!!
i lemoned my 1st 6. 7. in four months it spent over 40 days in the shop. A Cat, DPF, Sensors, four flashes, and two turbos later i got a new truck. this 6. 7 has been great, knock on wood.
Paul,
First, some empathy, and then some comment on a couple of the many points you raise:
If I had had your lemon experience, I would be exasperated and irate, and mistrustful of the future.
But note your so-far-so-good experience with your newer rig, and the same experience of myself and others.
Let's hope that the trouble-free (so far) trucks indicate that there is at least some potential for a fine working truck when all the newness is sorted-out, ... and that the troublesome trucks will serve to point out the bugs upon which the tweaking must be focused.
Now, about the "choking". Don't you think the Cummins engineers are well-versed about the capabilities of their designs? I don't think a dyno result is news to them. They KNOW what this engine is capable of, now, in the future, modified, stock, choked, free-breathing, ... whatever.
But they have a goal for the present, which is not just about power. They are trying to meet "adequate" performance levels, for the needs of their customers (and to meet sales competition) , ... while at the same time having emissions goals.
This demands compromises to performance. If the "choking" helps serve the emission reduction purpose, and still gives the customer a 350/650 performance level, ... then the compromise may be "acceptable" in a situation that dictates attention to both factors.
A great many owners have expressed delight with the power levels this engine gives. The more-is-always-better group, by definition, will never be satisfied.
So if D/C can deal with the issues you have brought up, even if the "choking" remains a required part of emissions reduction, the fact that the engine COULD be made to produce more power will be a non-issue for most owners, especially those who also share the viewpoint that less "stuff" in the air we breathe is a good thing. ;-)
In short, Cummins has given us stock, smooth-and-quiet engines with performance that would have been considered GREAT a few years back, ... with invisible exhaust, excellent exhaust-braking, etc. , etc.
Some, maybe most, seem to be doing OK. Others have more or fewer of the inevitable new-tech "bugs".
D and C are working on them.
Hopefully all we need is a good supply of patience.
Meanwhile, ... thank goodness for lemon-laws, huh?
