Keeping the RPM's up for me while pulling is essential with 90 horse added with my smarty and not slipping my stock clutch up a hill lugging my truck. I'm in desperate need of some Southbend action!

 

I tow 30K+ and the G56 is geared so low I put 22.5's on to lower my RPMs when towing. Truck pulls better at the lower rpms and is better on fuel.
As long as your happy with the way your truck pulls then keep doing what your doing

If your going 75mph and you come to a hill in 6th gear and your truck only slows down a 1-2 mph and your egt's are ok why downshift the 200 hp and 600 tq is more then enough for the job.
Remember gear up and idel down = better fuel economy!!
Now I can see if you needed to speed up then downshifting would be the think to do.
More then likely if I called I would be talking to someone who has never drove a Ram with a cummins diesel. And I don't really care what their opinion is. I know how my truck runs and where it runs it's best. If the engine can't handel peak tq when stock mabey they should derate the engine to a safe level
Try a real Dyno like at a big rig shop they run your truck up to red line and then pull it all the way down to 1200 or so and do this several times to give you your numbers. My peak tq on my 2000 was at 1450.
The 5 second dyno runs like you get from a dyno jet don't mean much to me. Think about it the person rows threw the gears and then they floor it. well if you think about it if they floor it at 13-1400 rpms your turbo might not build full boost until 2000 rpms. At least that is how my truck was. And you wonder why your peak tq is at a higher rpm

 

Think about what you said, You keep the RPM's up to keep your clutch from slipping. Is that because you have so much low end tq that your clutch will ship
Go with the DD form southbend mine works great with towing!!

 

Anytime you give the engine more fuel and it does not accelerate it is lugging.

Too many people try to run the CR's under 2k rpm's towing and all they are doing is reducing the life expectancy of the motor. All you get are high EGT's and excessive engine wear. When pulling the motor peaks TQ at 2500 rpm's and thats where it will run the coolest EGT's and provide the best efficiency.

As long as you keep the rpm's in that range and select a gear thats still allows acceleration there will be no EGT issues.

 

I NEVER said pulling hills in 6th was imposible. The problems come about when you can't run that hill in 6th and don't know enough to downshift. You get a new guy asking about his first Cummins,and you say "oh,I can pull any hill in 6th at peak TQ". So what does he do? He trys pulling a huge load up an 8% grade in 6th.He starts lugging the **** out of it,and he doesn't realize hes about to melt a piston or turbo,and 6th gear isn't made for that kind of abuse either,it is O/D afterall.

In that situation they'd be better served to hit 5th,bring the rpm up, make some HP and put far less strain on his engine and transmission.

As far as calling Cummins,your right,call their corporate office and see what they say. Call a Cummins tech and ask the same question. I already know what they'll say.

 

On a 04.5+ higher RPMs is when the 3rd injection even really kicks in and temps rise... But you still shouldn't be able to hurt a stock truck...

So your temps are hot, but should be safe....

The Jr is a great way to go. Under normal towing I haven't seen over 1250*. I did see 1400* once, but had a jet ski on the front of my truck so the coolant and IAT were much warmer than normal... And that was only when I went to 90% throttle towing up a steep hill, my fault.... normal hill climbing that day only say 1150*.

 

So are you saying you are towing TWICE the weight your truck is rated for?
Or is that your GCVW..

 

Don't forget what Cummins defines as lugging... its when more pedal doesn't increase rpm or speed... This can happen at ANY rpm.... So if your WOT and slowing, then you are lugging, time to downshift.

 

Where does Cummins say this? Not doubting you...just looking for the source.

RJ

 

I want to say it was in an email I got from Cummins, thou I can't find it... I was asking them about max TGT's and the like, and part of there response was to not lug the enigne, then gave that definition.

 

http://dodgeram.org/tech/dsl/FAQ/engine_op.htm

There is a link that discusses it as well.

 

Cummins did NOT define this nor in any way contribute to the definition. All they are doing is restating what everybody that drives a diesel knows.

 

Thats entirely possible, I just have been told it by cummins, hence the reference. And I wouldn't say everybody that drives a diesel knows this, I have ridden with many a people who will just put there foot on the floor on a hill and take what they get, faster or slower, or slowing...

 

There actually is a statement in the owners manual about lugging the engine and their definition.
But anyhow. I pulled my 10,000lb trailer up to the mountains this last weekend and my exhaust actually stayed cooler when I left it in 5th gear and sat at around 55 mph and would slowly drop to around 50 mph and would just hold around 50 at 1,280 deg. If I down shifted to 4th at around 2,800 rpm the temp went to 1,400 deg.
So for my stock engine its better to let it grunt up the hills than to scream it.
I am now ready for my Smarty Jr.
Thanks for the information all

Phil

 

Yes I tow At Least TWICE the weight my truck is rated for. Licenced for 38K been checked while loaded by DOT they have no problum with it.