I think another thing that people tend to forget is the torque management on these trucks.

We do not get the full power of the Hemi because it it held back especially at lower engine speeds. The 4.7 isn't quite as restricted.

Combine that with the fact that 4.7's usually have a shorter gear ratio than a Hemi then it would explain the 4.7's strength off the line.

However, once things get moving the Hemi will always win. Power is power. Gearing can only help for so long.

 

Revo, I agree with you 100%. My truck just seems bogged down off the line maybe it's the torque management. I did not have that with the 4.7. On another note the 4.7 from 70 mph on up was not nearly as strong as the 5.7, the 5.7 takes off from 70 mph on up. Pedro dog, no offense taken.

 

This truck MOVES from 80-105mph (limiter). On the open highway we have to pass sometimes multiple semi trucks against oncoming traffic and with our old 2002 with the 4.7, we would have to make sure we had a decent amount of time and usually pass just one or two at a time.

With the Hemi, it's a total breeze. Put your foot the ground and by the time you're near the front of the Semi you're at 90+mph and it's still pulling hard.

The Hemi is a beast up top. If Dodge gave us a true 6 speed and did away with those pointless gear ratios and ripped off the torque management, this truck would be a monster.

I can't wait for this Hemi to be put in a Challenger or something.

 

The 2002 4.7 is not the same as the 08 and up 4.7 my buddies 4.7 will get up and go from 60 mph to 100, but he cant keep up with my 5.7 though. www.allpar.com has a nice article on the hemi and the remake of the 4.7 semi hemi, the two engines actually have some of the same technologies. The 4.7 in 2002 had 230 horsepower, now it has 310. http://www.allpar.com/mopar/47.html Oh im pretty sure the hemi is allready in the challenger, in fact I think it has a 6.1 liter hemi

 

The Hemi in the Challenger is not the same Hemi in our trucks. The 6.1 is the SRT Hemi and that's a different motor as well.

The Hemi in the Rams have VVT - no other Hemi has this so far from what I understand.

Yes I know the 2002 4.7 is different, but in the end it's still a 4.7.

 

shorter gear ratio? aren't the trannies and rear ends the same?

I think that perhaps the torque management is key here. Does anyone here have any info on that? I'm really curious on how that gets done and what the diff is for the two engine packages.

 

The car motors have VVT. (check the chrysler website)

The difference between the 2002 4.7 and the 2010 are HUGE...

Torque management reduces engine output in lower gears to protect the tranny... it is part of the software package. Hopefully the rumoured new BMW style tranny fixes it.

The trannies are essentially the same, as are the rear axles... I would wager that more 4.7s are equiped with 3.92 final drives than hemis (proportionally) as the hemi has the muscle to turn a numerically lower gear, which allows lower rpm at highway speeds, and therefore better gas mileage. Of course the colliary of this is that the engine is under higher load so the MDS cannot kick in as much, but I am sure someone did the math somewhere...