Good to know. Is there anywhere I can learn about this?

 

Heretic,
I'm waiting to compare PSD to Cummins for towing. You pick the torque converter number (1.4, 1.5, 1.8 I don't care). You pick the cummins clutch engagement RPM, and tell my from your Cummins 600 curve what the torque is at that RPM. I'll do the math ...........

At parade rest ....

 

http://www.carcraft.com/techarticles/80098/

Try this for starters.

 

Now your typing, don't even need my glasses..and you thought I wouldn't notice...you o-devil dog....

 

Are you going to figure in the driveline losses into your numbers. That is a big factor that up til now we have ignored.

Ignore clutch engagement. Its like tmyers flash stall. Its only a brief point along the line of putting power to the groud. Its not how much power you deliver in an instant. Its about applying power over time. Whats 100000lb ft gonna do you if you can only apply it for one tenth of a second.

If you want to play with numbers. Go from 600lb ft at 1600. Im est. the 6.0 at 512lb ft at the same rpm. How much torque at the wheels in first for the pair. Manual vs auto. With a 5.69 first and a multiplication of 1.5 from the tc for the torqueshift in first with a 4.1 rearend. I dont know why you want to do the math. I can do it for myself. The manual will put more torque to the rubber in first than an auto can. What are you trying to prove? Autos are superior. There better at some things worse at other. They have their pricetag. Poorer economy and higher ownership costs. I believe they are useful. Depends on what you are using them for. If I was to buy a 6.0. I would definitely get the auto. Same with a dmax. If I was towing very very heavy and was in the market for a dodge. Id get the manual. If I lived in town. Auto. In a rural area. Manual. Wanted the best fuel mileage. Manual. Wanted to race. Auto. Wanted something to last forever and handle 1000lb ft of torque. Manual. You see. It depends on the application. Except in the case of the 6.0. Dont buy the manual. Its a bad pair. The torqueshift will deliver better performance.
I cant believe you bought a dodge with an auto.

 

Thank you tmyers. I also found this. http://www.turboaction.com/conv_techtalk.html

Brief but informative.

 

Okay,
Speaking of stall speed ... Heretic is stalling our comparison (for obvious reasons). I'll go with this: "Our test mule was a 1999 Dodge 2500 pickup with an automatic trans and 4.10:1 gears. It put out a respectable 411 lb-ft of torque at 1,800 rpm" source: http://www.fourwheeler.com/howto/7380/

Now, since this is the 2004.5, I'll generously add 40 ft-lbs, and we'll use an even 450 ft-lbs. I think that is MORE than fair, but we'll go with that. This is on TOP of the generous helping of 1800 rpms for clutch engagement, which is ridiculously high, but I'll be generous there too (Heretic said 1400). Secondly, since Heretic keeps mysteriously lowering the torque conversion number, I'll go with the rock-bottom mere 1.5 multiplier for the PSD.

DRUM ROLL ..... (whipping out my calculator)

1. TORQUE of the PSD at start of tow: 560 ft-lbs x 1st gear (3.09) x 1.5 torque converter (your number) x 4.1 rear end = 10,641 ft-lbs.
2. TORQUE of the CUMMINS at start of tow: 450 ft-lbs (clutch engagement) x 1st gear (5.63) times 4.10 tow-rear = 6925 ft-lbs at the tires = 10,387 ft-lbs.
   

Remove your hats, and let's pause for a moment of silence. Cummins, may you rest-in-peace as the former tow-king. May the Good Man above escort you to the heaven of great has-been light trucks. May His face shine upon you, and may our memories always be ones of delight. Amen.

Now, Heretic, the PSD will beat a Cummins in either:

• Speed and Acceleration ... or
• Towing

Any questions?

The Ironman

 

Same words, minus the typographical error on part of my paste. Re-stated (same results):

1. TORQUE of the PSD at start of tow: 560 ft-lbs x 1st gear (3.09) x 1.5 torque converter (your number) x 4.1 rear end = 10,641 ft-lbs.
2. TORQUE of the CUMMINS at start of tow: 450 ft-lbs (clutch engagement) x 1st gear (5.63) times 4.10 tow-rear = 10,387 ft-lbs.

 

Where do you get a tenth of a sec from? Until the pump, turbine and stater catch up to each other you have torque multiplication. That is normally about 40mph before you see that in most stock apps.

 

Ironman, I know very close to nothing and you are sounding less intelligent by the minute. That addition of 40 ft. lbs. is actually LESS than fair especially since you are going by a 99 auto. The 99 cummins is listed as 230 hp, 450 ft. lbs. of torque. The 2004.5 is listed as 325 hp., 600 ft. lbs. of torque. At 1800 RPM the 2004.5 Dodge Ram is going to have more than 450 ft. lbs. to the wheel. Probably closer to 550. Again we are comparing the Dodge Manual to the Ford Auto since the Ford manual is a joke and the Dodge auto sucks. The original post of Logical Heretic that this whole debate originally spawned off of was him saying the Dodge tows BETTER(driveablity). Than you start going off about the Ford towing FASTER(acceleration). I repeat FASTER and BETTER are different things. Nobody ever disputed the PSD's ability to accelerate faster. The dodge manual tows more efficiently than the ford auto. And Logical Heretic I bet I could beat you at chess .

 

Diesel Doner,
I didn't just add 40 ft-lbs. I tossed on about 800 rpms too many, and reduced the torque converter factor for the PSD to a ridiculously low 1.5. Let's go back to the original findings:

PSD at tow-start: 560 ft-lbs x 1st gear (3.09) x 1.8 torque converter x 4.1 rear end = 12770 ft-lbs.

What engine torque would the Cummins need to match this? 12770 needed divided by 5.63, divided by 4.10 = 553 ft-lbs of torque. You said in your post that the Cummins has 550 ft-lbs at 1800. That makes you 3 ft-lbs short. Yes, folks, still 3 ft-lbs short..

It's apparent that the pro-Dodge crowd here is not going to succomb to technical analysis. If you work really hard, I think at best you could find a small subset of assumptions, largely stretching the truth, which will edge the Cummins higher. But my analysis for my clients is always objective, and this is, too. Thus, when I see these tow-tests in which the PSD/Auto wins hands down ... I'm simply not surprised. And theres no question that once forward-motion begins, the PSD/Auto, by design, simply out-gears the Cummins/NV5600 all the way down the line. In my PSD, at 2000 rpm flat, I'm doing exactly 73 mph. My Cummins prefers sitting down around 1500 to 1600 rpm. If I gun it to 2500 rpm, it starts creaking and groaning, and rattling and rolling. She don't like 2900 rpms, it scares her. But my PSD ... going 73, I checked it today, if you give it a I-want-to-get-past-this-car step ... it winds to 3300 rpm within 1 to 2 seconds, and you're given a new part in your hair. WITH 14, 200 lbs behind you, if you're driving an F-350 5th wheel rig.

"Tell it to the Marines"
an old cliche ... means Marines give you the God-s honest truth

Marine Ironman

 

Ok you must be taking your original torque figure from the maximum possible fly-wheel torque which is 600 ft. lbs. on the Cummins. I was going by torque to the wheel silly me. But wait, your going by peak torque on the PSD because when you floor it it goes directly to 2100 rpm which is peak torque rpm. Meanwhile the Cummins when you drop the clutch is grossly under peak torque rpm and you have to work your way there. Even at 1400 rpm its at peak torque just lower horsepower. Now the point of all this is the PSD can tow heavier? Because we already covered that is tows the same amount of weight faster because of the advanced gearing of the Torqshift. So basically the PSD auto beats the Cummins manual even worse than the Cummins auto... which is what I said to begin with. Well dang, Dodge needs to get some of this advanced gearing on their auto wouldn't you say Logical?

 

I question how you got 455 for one and 560 for the other. If we are grabbing numbers out of the air. Why not go big?

A 99 cummins auto produced 420 at the flywheel. Im glad you compared two similar specimens. In other words. Those are the most b.s. numbers you could muster to bolster your claim. Which is mistaken btw. This is what I was referring to when I said create reality to fit your preconceived notions. Autos may, just may, produce more torque for the fleetest of moments. Manuals can sustain it.

A 6.0 does not make 560 til 2000 rpms. At 2000 rpms a cummins has been making 600lb ft for 400 rpms. Why not use comparable numbers. Ohh I see. Its because autos throw away rpms to multiply the torque. Well even at 1.86 The manual still makes more. I see. You were mistaken and cannot accept it, or admit it. Its ok to be mistaken. No crime in it. Repeat after me. A manual gets more rpms to the ground. A manual can get more torque to the wheels because of its generous first gear. Its a granny low. The auto will accelerate faster even if there is more torque. Because as you pointed out. It must shift after just a few feet. The multiplier is still slightly in favor of the manual but the auto is faster.

The 6.0 makes 50 lb ft while its cranking so if I add this up and that. 400lb ft. Compared to 40,000 that my bike makes. See, I can make anything sound better if I use numbers out of left field.

 

The flash is very brief. I was under the impression it lasted a very short period of time. Regardless. At 2 to 1 it is difficult to make more torque at the wheels than a granny low.

 

600 above 1600. 555 above 1400. Do the math with the correct numbers. I can post crud rediculous numbers but I refrain.