Mega cab difference?!?!

[Ratket]

So I know supposedly the 6.4 Hemi mega cabs are rated at a slightly lower hp/ tq and we don't have the center shock from the axle to the frame out back. Sooo I really have never found a definitive answer on this. I know guys say they can smoke the tires on their 2500 crew cabs, Sadly I can not. So is it just tuning? I mean that's all that could be different right?? But why? any one have any answers? Thanks fellas.

 

[Ionicbrick]

Where does it say they are rated for less hp and torque? I can break the tires on mine easy... But you do have to turn of the traction control... These crappy FS tires probably play into that a bit...lol

 

[hemi1282]

U can't smoke your tires? Ya should be able to I can, I seen where somebody posted the shock is for wheel hop and the mega cabs don't need it, dunno how true that is but every mega cab I've seen with a 6.4 none have them I've checked most of'em around here but ya with factory rims tires mine lights them up

 

[Ratket]

What elevation do you guys live at? and I swear I saw in the brochure the mega can had less hp/ tq - I think it was the way they dyno it.

 

[Ionicbrick]

I'm at 5400 near Denver. I've not seen such a brochure or dyno numbers... You don't happen to have a pic or link to either do you?

 

[Ratket]

http://www.ramforum.com/f158/6_4_hd_hemi_thread-41378/index12.html

Found it here- from another post I will keep looking though. About half way down on that page there is a link.

 

[Ratket]

https://www.ramtrucks.com/en/pdf/2014_ram_chassis_cab.pdf

Page 3- " The ram 2500/3500". Zoom in and you can see it. Derated from 410- to -367.. One answer I got was the way it is dyno"d. But I dunno..

If this is legit then the only fhesable way to de rate it would be through tunning. Any thoughts???

 

[hemi1282]

South Arkansas here, elevation like 250 I think that detune only applys to the 3500 mega cab

 

[Ionicbrick]

I thought that was for chassis cabs only. That is a commercial brochure on the link... Maybe it's just confusing? I still haven't seen any dyno work for any of the 6.4's... Anyone know of any?

 

[EvanYJ350]

I read somewhere that it was a weight class issue, and that they measure it differently at a different RPM. Same engine, same power, just measured differently.....

 

[SilverSurfer15]

thats weird...

 

[loveracing1988]

I read somewhere that it was a weight class issue, and that they measure it differently at a different RPM. Same engine, same power, just measured differently.....

This.

 

[drittal]

Is the engine governed to lower RPM?

 

[loveracing1988]

Is the engine governed to lower RPM?

No, just the rpm at which the hp and tq is measured is lower.

 

[SouthTexan]

The 6.4L and Cummins in the chassis cabs are rated lower because they have a different emissions certification they have to go through than the pickup versions. They have to go through a different certification because Ram does know what body the end user will put on the truck so it cannot do the same emissions certification as the pickups with beds. They run the chassis cabs through what is called an engine only certification which is more stringent than the pickup one.

 

[Skrap]

The 6.4L and Cummins in the chassis cabs are rated lower because they have a different emissions certification they have to go through than the pickup versions. They have to go through a different certification because Ram does know what body the end user will put on the truck so it cannot do the same emissions certification as the pickups with beds. They run the chassis cabs through what is called an engine only certification which is more stringent than the pickup one.

So, I assume the MC are not detuned? Only the Cab and Chassis models are?

 

[Ratket]

I don't think any of them are de tuned.. just the hp/tq ratings are different because they are measured differently. But in reality they are the same?

 

[NewBlackDak]

None of them are detuned. It has to do with noise levels, and they can only measure the HP/torque at max decibels.

 

[SouthTexan]

So, I assume the MC are not detuned? Only the Cab and Chassis models are?

No, the MC should not be tuned differently and it should only be the cab and chassis models. They use the same SAE standard for both numbers, but the engines are tuned to meet the emissions certifications. Many people believe they are tuned for reliability of the heavier duty cycle, but this just isn't the case. It has to do with emissions just as the representative from Ram states in the video below.

https://youtu.be/TNRwwUIsG4Q?t=3m43s