Engine/Transmission (1998.5 - 2002) Questions for those in the know......

[hensign]

I have recently returned to the Cummins after a short spell on the dark side... I have what may seem as a silly question to some. On my last and now this truck, both 99's, I notice a decent increase in power after >100 miles of towing. This increase continues for about 100 miles after towing. I know that the computer learns the driver expectations and alters fueling as needed.

Now for the question. Anybody ever dynoed thier truck while experiencing this increase in power? What kind of an increase did you have?

I have decided to do a little performance work on this truck, air box, 4"exhaust, and a power box(probably Van Aaken) . Do the perfomance increases exceed the power increases seen after towing? I willl also see better perfomance while towing?

Thanks for any answers you may be able to provide.

 

[jtisdale]

no dyno numbers but,

Yes, you will see more performance all the time compared to the increase you see after towing.

 

[tgee]

When you say the computer learns driver expectations, you are referring to what is called Adaptive Memory. I didnt think the Cummins ECM was capable of this. I know some ECMs out there are, like most Allison trans ECMs. Anybody have some insight on this?

 

[hensign]

The computer can definitely "learn". After towing my old 38' all steel Gooseneck trailer(14k lbs empty) the truck would be almost undriveably, pulling away from a light with only moderate throttle would have the tires spinning. Kinda fun but rough when the weather is bad.