800 ftlb torque limited?

[g_dog1]

Hi guys. I know some of you are very exceited about the new HO 6. 7L engine with 800 ftlb of torque. I see it is only available with the Automatic Transmission. Here is my question. Does anyone know if this torque is electronically limited in first and/or second gear?



Chrysler has been known for making large output numbers (300C with hemi), but all that power isn't put through the drive train until higher gears in the transmission are engaged, other wise drive train components will break. So far 800 ft lbs of torque isn't aiavaible in the manual transmission and I am guessing it is for a couple reasons... . 1. Transmission can't handle it. 2. If the trans could handle it, in low gear, the drive shafts and axles couldn't handle it. This is just speculation until I find out the answer to my first question.



800 X 5. 94(1st gear) X 2. 72 (xfer case ratio) = 12925 ftlbs in the drive shaft and u-joints. The axle shafts would see this X about 4. Needles to say that is a lot of torque.

 

[HBarlow]

I have learned recently that Dodge/Ram has apparently been using ECM torque limiting in the lower gears for several model years. I tried unsuccessfully to get Cummins engineers to answer my questions on the subject but Steve St. Laurent's excellent article on the new HO 800 engines reported that he was told that torque limiting will be used.

I would assume torque limiting.

 

[RustyJC]

IIRC, I read that the full 800 ft-lb will not be available until 4th and higher gears. My 350/650 engine is perceptably torque limited in the lower gears; I can especially feel it in 1st.



Rusty

 

[ddargay]

I just purchased a 3500 SRW off the lot. I wonder if dodge is going to offer a software upgrade for the 350/460 engine that I have. Wanted the HO engine, but coud not wait the 10 week delivery.

 

[SierraRam]

I know my 07 G56 is TQ limited too, using the smarty it is clear when making adjustments the the TQ leved. I know my modded 07 5. 9 make well over 800#ft of TQ and noproblems with the drive train excluding the clutch.

 

[RobertHiltz]

Torque and horsepower management is not anything new. Computer controls make this easier to do. I would bet Ford and GM do similar things too. Instead of looking at management as a negative you should also realize that it allows for higher torque and hp when it can be utilized and still retain a high level of reliability. Over the years the peak hp and torque ratings are often for meeting the competiters advertised claims and they are all doing the same thing. It sells more vehicles. Those peak ratings might not be reached very often in real world useage. I find it interesting that just a few years ago Ford and GM focused their advertising on horsepower (when everybody knew the Cummins would out pull them in a grade) now they advertise load pulling capability. Apparently Ford and GM believe that their products can finally do the job, and do it well, that trucks are supposed to be able to do. I think the jury is still out on that yet!!!!!!!

 

[ddargay]

So far I've only taken my truck for test drive, will pick up on Tuesday, but what a difference with the 6. 7 engine and 6 speed transmission. I had a 2003 5. 9 engine with EZ module and the old 47RE transmission. This new ring is soooo! nice. Shifting is much more positive. Can't wait to pull our Big Country 5th wheel with it. I'm going to love the exhaust brake in the hills and mountains. We do have enough of them in PA. Probably the 350/650 6. 7 may be all that I need. My 5. 9 pulled the trailer very well, the only draw back was the 4 speed 47RE transmission.

 

[Cosmo]

You better believe Ford and Chevy use torque limiting logic...

I'm a Subaru mechanic but we (subaru shop) do all the used car inspection/repairs for our Dodge/Jeep/Chrysler and used car lot trade-ins and today I got to drive a 2004 F-350 6. 0... . that thing was a TURD in first gear. Plant the throttle and it would slowly wind out first gear with I'm guessing MAYBE 10psi max, up to ~3500 rpm, shift into 2nd and then it would build boost and start pulling like crazy.

Going from my over-1000 lb-ft non-managed truck into a torque managed 560 lb-ft truck makes it even more noticeable. That thing wouldn't even think about chirping a tire.