Took the plunge - Cummins to Hemi 6.4

Bigfoot affair wrote:

blderman wrote:
Here is a brief example based on trans/rear end gear ratios. I know this isn't proof of anything but it shows the design flaw, in my opinion.

Ram 6.4 (420ft lbs @ 4000 rpm)

1st Gear 3.23= 1,356 ft.lbs x 4.10 rear= 5,559 ft.lbs
2nd Gear 1.84= 772 ft.lbs x 4.10 rear= 3,165 ft.lbs


Chevy 6.0 (380ft.lbs @ 4200rpm)

1st Gear 4.03= 1,531 ft.lbs x 4.10 rear= 6,277 ft.lbs
2nd Gear 2.36= 896 ft.lbs x 4.10 rear= 3,673 ft.lbs


So mathematically speaking the Chevy has 718 ft.lbs more in 1st gear and 508 ft.lbs more in 2nd gear. If my math is correct that is a substantial difference in torque to the rear wheels. If the Ram had the same gear ratios as the Chevy it would have walked away easily.

LOL! So how do you explain the Chevy going up the Ike in second gear? It only shifted into first just before the top of the mountain.

Face it, the Ram 6.4 is all paper #'s and was beat by a engine trans combo that was put into these trucks back in 07.

How do you explain the other tests results then if the numbers are "all paper"?

Here are the graphic representations of the results for all of the testing done by Pickuptrucks.com - excluding the Eisenhower tunnel test:













See what I mean? Ram takes first place over and over. Loaded, empty, uphill, on the flats, always fastest.

Is isn't until they test it on the Eisenhower Tunnel grade (same as used by TFLTruck in their "Ike Gauntlet" test) that the Ram was slower. I chalked it up to the fact that it was carrying between 2000# and 3000# more than the GM and Ford because they loaded all the trucks up to 90% of their GCWR and the Ram has a much higher GCWR so it had much more weight.

It appears though, that it was the extra weight AND something to do with the engine programming for high elevations.

Here is the Eisenhower tunnel test done by PUTC:



And the note that followed the description of their Eisenhower tunnel grade towing test:

"How We Did the Testing

We knew we wanted to do something special here, so we opted to run each truck as close to its manufacturer-stated GCWR — meaning all it can carry and tow. Simply put, we wanted to see how well or poorly they performed at their limits. We know most people aren't likely to do this kind of towing (and if they did, they'd probably buy a one-ton dualie turbo-diesel), but how well a pickup does near its limits is likely to say a lot about how well it will do when things aren't so tough.

Our trailer for this event, when empty weighs, about 6,000 pounds but we had two 330-gallon water tanks (each weighing 2,800 pounds) wedged inside, bringing the total weight close to 12,000 pounds, near but not over each truck's stated maximum conventional tow ratings.

The F-250's GCWR is 19,000 pounds; the Chevy's is just more than 20,000 pounds, and the Ram 2500's is just more than 22,000 pounds. We attempted to adjust each max trailer weight by dumping a certain amount of water from each truck or trailer, getting as close as possible to 90 percent of the vehicle's GCWR number."