Ram 2500 6.4L 12.5K Ike Gauntlet
TFLTruck did a Ike Gauntlet tow test of a 2015 Ram 6.4L 4.10. Identical axle ratio and load (12.5K) to the 2015 Chevy 2500 they tested a few months ago. The Chevy gives up ~50hp and lb-ft. Surpris...
Forum Discussion
ib516 wrote:
Here's what was added by the guys from TFL in the comments:
Ram Truck “invented” the first gear hold feature – and calibrated it – to avoid gear hunting and driving at excessively high rpm’s.
Ike is a variable grade and we worked hard to develop a calibration that appropriately manages torque on the run and other grades.
We don’t want the truck to rev high for extended periods of time and purposely hold 4,200 rpm.
Seems like there's some designed in limiting by the PCM/ECM going on here.
Interesting. I wonder what the Ram powertrain engineering folks would say about needing to avoid more than a sustained 4200RPM. Cooling limitation? BMEP? Transmission limitation? Rating a motor at 5600 RPM and only using 3/4s of the HP is surprising. I wonder how the PCM would know to enforce limit, as it would be too obvious to do it on the 1-2 upshift, and way too obvious to just pull fuel from the driver when holding in first to bring RPM from say 5000 back to 4200. Perhaps only on the 2-1 downshift then it applies the 4200?
IB516--have you noticed any PCM/ECM limitations along the lines of what Ram described in your towings?
