4x4ord wrote:
The detail that would add some clarity to your BSFC map would be to mark the average Nm output of your engine. Then focus our attention on the part of the map a little above and a little below. If the load becomes moderate to high in 5th we already agree that a downshift is in order. Our difference is that I believe the engineers who design the trucks know when this downshift should take place better than we do and design the trucks to make the downshift at the appropriate time. You seem to think the rule is that if tow haul is needed 6th should be locked out. If conditions are such that the transmission is annoyingly shifting back and forth I would say that is one time I’d lock out 6th.
Can you please email a Ford or Ram transmission engineer and ask them what the TCU utilizes to determine shift points. It would make things a lot easier because it is not as easy as you think.
And I do find it funny that you are telling someone who has worked for various engine/vehicle manufacturers how easy it should be. That is like me telling you how easy it is to do your job without knowing the intricacies of your job and what tools you have to work with.
