jpgmtech
June 13th, 2008, 02:25 AM
Hey guys, first off thanks for the support for the LMM's!:rockon: Eliminating the DPF system has sure proved successful for fuel economy.
Having done a few, I have noticed a couple of things that may indicate that the DPF system could be improved considerably with programming.
1) These trucks smoke black a bit more than the older LBZ with an aftermarket exhaust and just the DPF system turned off (all other parameters stock). That leads me to believe that GM chose to improve the responsiveness of the diesel now that they had an exhaust filter to catch the particulates. Problem is, that will only plug the filter sooner, requiring more regen cycles.
2) These trucks will naturally regen (passively) going down the road. However, there is a mileage limit that will always force an active regen even though the differential pressure is just fine.
3) Again, on the previous point, there is also a maximum fuel used limit to force a regen.
I guess what I am asking is if Ross and company could unlock the parameters that govern the regen modes (more than just shutting them off). I think that we could pick up the fuel economy significantly and still retain the benefits of the particulate filter system by making the regen more filter condition dependant and reduce the smoke on accel. This would also increase the service life of the DPF system... at least in theory anyway but we won't know until we try.
Having done a few, I have noticed a couple of things that may indicate that the DPF system could be improved considerably with programming.
1) These trucks smoke black a bit more than the older LBZ with an aftermarket exhaust and just the DPF system turned off (all other parameters stock). That leads me to believe that GM chose to improve the responsiveness of the diesel now that they had an exhaust filter to catch the particulates. Problem is, that will only plug the filter sooner, requiring more regen cycles.
2) These trucks will naturally regen (passively) going down the road. However, there is a mileage limit that will always force an active regen even though the differential pressure is just fine.
3) Again, on the previous point, there is also a maximum fuel used limit to force a regen.
I guess what I am asking is if Ross and company could unlock the parameters that govern the regen modes (more than just shutting them off). I think that we could pick up the fuel economy significantly and still retain the benefits of the particulate filter system by making the regen more filter condition dependant and reduce the smoke on accel. This would also increase the service life of the DPF system... at least in theory anyway but we won't know until we try.