J BODY

Any reason the post on this subject was closed with no replies? I felt it was a very good question so here's my reply.....
The CTD engines are VERY de-tuned for our application. The whole drivetrain is designed as a whole unit "engine, trans, drive line, rear end, towing capcity, braking, etc...". The engine output is basically brought down to a level at which the engineers feel that the current trans and diff will stand up for an extended period of time, yet deliver an output level that the customer is happy with. Of course as you can see by the "bombing" that goes on few seem content with the factory hp/torque settings. If approached correctly you can up grade your truck, but you need to look at the whole drive line, not just the engine. Also the computer controls the timing and fueling and you would be hard pressed to enter into a "danger zone" as far as over working the driveline in stock form. By adding a "fueling box" this often allows the operator to push the engine into areas that can be harmful to the longetivity of the power plant. This is why the first mod suggested is often a good set of gauges followed by some tranny mods. It's easy to upgrade the output of the CTD, the trick is to upgrade the rest of the drive line to put up with the added power it was not designed to handle in stock form. You will also need to "learn" how to drive by your gauges and keep your exhaust temp in a safe level of operation.

Alan_Reagan

As far as the question "Are they harmful", I have to think that like any other modification, it depends on what you do with it. If you abuse the power, it will be harmful to the engine.

I remember right after the 24V engines came out, one could go to the dealer and buy Cummins power upgrades from the Dodge dealer. Obviously, Cummins thought the engine was capable of handling the power upgrade. The reason it wasn't already there probably had to do with emissions.

Even without the fueling upgrades, if you constantly romp down on even a stock engine throttle, the drive train will suffer. Hard braking, burn outs, towing excessive loads, running high EGTs (past acceptable limits) and other abuses will be harmful.

I use a fueling box. I don't race. I want the power when I'm towing. If I want to play, the power is certainly there.

Cumminsdude

As far as DC not putting this on. I would think because with these boxes it does however shorten the life of the stock tranny or clutch, which would probably cost DC too much to redesign and install better tranny's and clutches. Another reason may be because it is a good thing to have guages after you add any hp and that is just another added cost. My guess is it costs too much. DC can program these trucks with their computers to run with more hp and torque so a box would not really be necessary but I'm not real sure why they don't just do it from the factory. May be a problem with emmissions and other things.

gsdog1

FWIW and IMHO, it ain't the engineers making the decisions, it's the bean counters.....go figure.

Matt

Alan_Reagan

You are right on the bean counters making the decision. If you have to put in a clutch that will handle 700-900 ft/lbs of torque rather than the 545, it's gonna cost. They tend to go for the masses that tend to drive the truck as a daily commuter not as a work vehicle. Case in point is the 03/04 models and the 75w90 rear lube that they recommend the new owner change to the 75w140 if they are going to be towing. What a bunch of bull that is.

Grey Rider

Alan,

Actually, the 75-90 is a full synthetic formulation, and in the 3rd gen trucks I don't believe there is any recommendation to switch to 75-140 for towing. They say to use the 75-90 no matter what. In fact, Dodge will not sell you 75-140 full synthetic approved for use in the AAM rear end.

As to the (potentially) harmful effects of a fueling box, all I have to say is "nothing in life is free". If you increase power output, you pay in lifespan. Now, the price might not be very high (couple hundred hours to rebuild sooner?), but it is a price nontheless.

But that's just my opinion, and I could be completely off-base.

infidel

I agree 100%.
It only makes sense that the more power you put to engine the shorter it's life.
Whether it matters enough is up to the individual.
Most Cummins engines are going to outlive their owners anyway.

Alan_Reagan

My 2001 manual states:
"If you plan to utilize your vehicle to pull a trailer for significant number of miles, reduce the potential for rear axle overheating by replacing the rear axle lubricant with an SAE 75W140 synthetic gear lubricant. Mopar Synthetic Gear Lubrication is of this type."

That's page 159 in my book. My truck (according to the owner's manual) came with 75W90.

When I looked at a 2003 at the fair last year, I checked the book and found the same paragraph.

Now, I agree that the synthetic 75W90 is fine. That is what most OTR tractors use. However, Dodge (or Dana or whoever is making the new ones) must feel that a different lube is required and that it is up to the owner to put it in. I'll look around for some posts but I seem to remember some owners of 3rd Gen trucks complaining about this.

Edit: The change came with the switch to American Axles. AAM recommends the 75W90 while Dana recommends 75W140 for towing. Sorry for the confusion. I'm not sure if some of the early 03s have Danas or not but I have run across this issue before. I'll look around.

Alan_Reagan

Not to beat a dead horse, but go here:

http://www.turbodieselregister.com/f...ight=Lube+Rear

There is a copy of the fax discussing the Dana, AAM and Corporate Axles where the different lubes for Dana and Corporate was recommended.

On the boxes, I still don't believe they hurt the engine although they do provide the driver with the ability to do so. I'll use a different example next time.