I gotta back up and possibly eat some of my own words here.....
Per==schooling for emmissions here goes...
The emmisions MAY be cleaner for certain types of emmissions. Say NOx. Cylinder temps determine the amount of Nox produced. Hence the reason the ealry ones had stamping on valve covers for the total Nox output. Add fuel= more Nox. Stop up air filter=higher EGT= more Nox. Or , preduce the same amount of Nox at a higher rpm= more total Nox.
By making split shots they kinda reduced Nox by reducing the cylinder temps. Two small shots of fuel shouldnt get it as hot all at once, but by having two burns, in my mind then you added to the time its at that temp, making it go back up???
Timing probably has a difference too.
But it works like this--
Hotter temps= more Nox AND less unburned CO (basically fuel)
Lower temps= Less Nox AND more CO.
Theres a happy point in the middle where they kinda even out, and both are at the lowest total level possible.
Higher power levels will make more of both. Out of balance cylinders make more of both.
Mechanical problems make more of both.
Bad thing is, fuel economy is not necessarily the best at the point where they are both at the lowest.
Power output isnt either.
Keep in mind I'm talking cylinder temps..NOT EGT.
So, more advanced timing should cause more NOx, while more retarded timing should cause more CO.
Kinda like the boost levels. Add timing, boost falls off, retard it and it goes up. I've seen this in my truck , and its not by just a little bit that it changes. Went from max of 42 psi on more advanced timing to just over 55 with less. EGT went up to, but not by a huge amount.
Smoke out the tailpipe also. With more timing, =less smoke. So, it seems that all that applies to diesel pretty good.
My question is, at what point between "clean" diesels, and old style pre-DPF stuff, is the happy spot?
At some point there has to be a line you cross where the drop in mileage (extra fuel being burned) negates any drop you had in emmisions output.
I mean really, by blowing 100 times the volume out the tailpipe , of cousre it reduced the PPM in bad stuff. But theres was 100 million times more total output, so wheres the gain?
If thats all that matters, then those of us with big singles should be fine on emmions as long as its spooled up real good! hahah Or....everyone should go get compound turbos installed, even if they are so little they stay spooled all the time even at idle.:bowfast:
Charlie, go get you truck tested in your tow tune, and let us know in PPM what its making!
I bet its close to what they are doing with the new ones, if not better. Oh yeah, do it in drive too, to keep the flow up out the tailpipe.