Finally... Got my TDI

[usergone]

Cummins TDI, that is. 1994 Dodge Ram 2500, Cummins 5.9, NV4500 5 speed.

The thought of having a computerless engine has been knocking around in my head for a while now. Finally got it.



The first "efficiency" mod I plan to do is a MUCH taller rear end. The NV4500 tranny it has now is more or less a 4 speed with a low gear. I don't ever use the low gear, so if I get a taller rear end, it will essentially give me one more overdrive

As far as the "normal" car buying stuff (lol, on this forum?) it has 263000 miles. When I really got into it cleaning, it looks like it could have less than 150k on it, but it's really dirty. Fortunately, cleaning the seat and carpet were easy (hot water, shop vac). Headliner is coming soon. Oh yeah, and it has no dash. These trucks have a dash made of some really bad dashboard material: it cracks like crazy.

I have not yet gotten a baseline on its FE, I haven't even topped it off yet. Only got it on Wednesday.

As far as the jeep, I know that it doesn't have as much efficiency potential as my jeep It weighs 1800 lbs more, and has 3.4 more liters of displacement. But that is not all that I care about.

Also, I am selling my jeep. I am asking 1900. PM me if you please.

[JasonG]

I believe I have the same tranny, and I love it.

I got good results putting synthetic and Lucas in the rear pumpkin. I cant give up my 4.10 gears with the trailer though. You should be able to find around 3.5

[Big Dave]

You should easily find 3.55 gears. Maybe 3.31s are available.

That torque monster engine will turn any gears you put in it.

Really good MPG also entails aero cleanup. Start with a tonneau. They help a bunch.

[usergone]

On the highway, I can definitely tell it is dragging. I will be looking for something that seems vaguely aerodynamic or just build something else.

I was actually considering 2.89 or 3.07 gears. I'm not sure what I have now, but I want to make my "low" gear have a final drive ratio about equal to the final drive of "second" (next one up)

Another "economy" thing I am doing to do is to run biodiesel. There is a place near my house that sells it for 2.55/gal. Compare that to the current 3.09 most everywhere else.

[slowmover]

I think the stock gearing is 3.54. You might investigate over on Dodge Cummins Diesel Forum and Dodge Diesel - Diesel Truck Resource - Cummins - Home as well as Turbo Diesel Register as to stock tire height and gearing to see what others have done with your gear/tire rolling height question.

Dodge Cummins Diesel Truck Accessories – Geno’s Garage plus Dodge Ram Information are good for searching out TSB's and some basics about the truck: the "killer dowel pin problem", the VP-44 fuel pump, etc, that ought to be higher on the list than new gears. Genos is a reliable aftermarket supplier as well. You ought to find the biodiesel questions there as well.

I find that on mine (2004, NV-5600 trans) that the 3.73 gears really is a perfect blend of power and economy. Once a trailer hits 7k the truck would struggle with taller gears while in the hills, I think, and I prefer to keep my options open towards maximum trailer weight and truck bed payload. I disagree about bypassing first gear (Chrysler and NV both say all gears all the time) as it gets the truck rolling so easily, smoothly and staying away from engine stall. I know others skip first, but I recommend trying it. (I've been a CDL driver in a few incarnations).

As to an LRR tire, the MICHELIN LTX A/S is rated as such. I'm not the only one averaging 120,000 per set when pressures are set according to scaled weight. I'd be tempted about he 16" XPS as it can be retreaded. BILSTEIN shocks are also a no-brainer, and a THUREN steering brace (as I had on my last truck) is also recommended. (SAFETY LANE in Garland is the best alignment/FE shop in D-FW).

I found that CASTROL purple cleaner was great on cleaning the nasty stuff when presented with a 750k mile Freightliner. Mix a bottle 50/50 and one full strength.

As to oil & filter I find that T6 Rotella 5W-40 allows easy turnover, and that the BALDWIN Venturi filter can be found for a good price online (or the FLEETGUARD version at FLEET PRIDE or other locally. Stewart & Stevenson off I-30 for DONALDSON ELF7349).
http://www.baldwinfilter.com/literat...ts/form331.pdf

We use the BALDWIN P7977 2-micron filter on the third gen. There ought to be cross-ref for something similar on the second. Same for the new 4" factory pleated air filter. I change oil, fuel & air filters at every oil change 6-mos/6000.

Got a picture of "the dashboard" for us? If you go to digging thru boneyards, see about the Sport model headlight DIY upgrade RIK-RAM http://www.danielsternlighting.com/p.../products.html (great guy to deal with over the years; read thru his site).

http://www.cumminsforum.com/forum/94...onversion.html

I like Big Dave's comment elsewhere that it boils down to gearing and aero. Put it on a certified scale with full fuel and driver to see where it starts! (Down on I-20, CAT Scale). I moved out of Dallas after 50 years, that pic above looks like our neighborhood near White Rock.

While a TDI would be nice, a CTD sure is practical!!

.

[usergone]

Thanks for all that info! I am already on cumminsforum and have been doing my homework on these trucks. The main difference from my jeep to this is that everything is bigger - parts AND prices.

Originally Posted by slowmover

While a TDI would be nice, a CTD sure is practical!!

.

How about a CTD TDI? It is a turbo, and it is direct injection.


Also, I don't really understand how a taller rear end worsens my towing ability... I can just stay in a lower gear a little longer, no? Sure, for a given gear, the torque at the wheels will be less, but I don't generally shift based on road speed. I shift by the engine's speed. Maybe my thought process is skipping some detail, but I will still have the really short first to use. So, essentially I will move a gear down in normal driving I'm sure someone can chime in to clear it up for me

Here are the overall ratios with the given rear ends. Note that first in 2.89 is still not as tall as second with the 4.10.

		Trans   4.10	3.54	3.07	2.89
First Gear	5.61	23.0	19.86	17.22	16.21
Second Gear	3.04	12.46	10.76	9.33	8.79
Third Gear	1.67	6.85	5.91	5.13	4.83
Fourth Gear	1.00	4.10	3.54	3.07	2.89
Fifth Gear	0.73	2.99	2.58	2.24	2.11

					
Ratio Jump
	(1-2) 1.84		
	(2-3) 1.82			
	(3-4) 1.67				
	(4-5) 1.36

Also, here is the dash:

[slowmover]

The short first gear is to get it moving. Perfect when heavy. And diesels cannot wind up to make HP like a gasser. The rpm range is narrow and the sweet spot only about 200-rpm. I think it no mistake that Dodge made (at least the 3rd Gen) sweet spot for the highway at 55-65 mph, broadly, 58-62 realistically. I use 1,700-1,900 rpm for all miles, town or country (18-20 city, 24-27 highway, solo). Load that baby up with weird gears and you may not like it . . . . hit Ranger Hill west of Fort Worth is only one example, as Texas is the world of wind..

Cummins has on their website a number of tools for business truck drivers. Gearing for highway is different from gearing for city. Gearing for power is different from gearing for economy. Trying to get all four of these -- city versus highway, power versus economy -- together in one truck is harder than it appears. Changing one aspect means worse performance in another. The trade-off may mean great highway mileage, but the performance sucks in commuter traffic. Etc. Just be careful is what I'm trying to say.

Given the age of your truck, the need to see to reliability, and the need to learn to drive it for best effect, spend the first year or so on the above, and maybe play with some of the aero mods being done around here (BamZipPow is a blast to read, as but one of a number of examples. But be careful about the Ford guys, as always ). The tires plus the driver are where the big gains are at first. Truck spec is most important, then climate/topography . . but the difference between all drivers is worth 30%.

The gearing is already good, or very close until your records show the amount of hours/miles broken out for the driving you are doing!! In the end it will be bout gearing and aero. But not in the beginning.

I put economy this way about CTD in posts elsewhere with more detail:

Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Why did I buy a diesel?????

Better MPGs ?? - Dodge Cummins Diesel Forum

Dodge Cummins Diesel Forum - View Single Post - Best MPG possible

Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Is 28MPG possible on a CR?

Thanks for the pics. I was trying to imagine no dash. I have had some really old cars with no dash. But, they practically had no electrics either (about 20' worth in the whole car, not two miles like today).

And, you need at least one pair of vise grips, clamped, sticking up from the dash to give the proper appearance, ha!

.

[usergone]

Yeah, I should have said the "dash top" or "dash cover" instead of "no dash" (because it still has everything about the dash except for the cover).

Thanks again for your explanations. I guess that for now, I will be tuning/standardizing myself as I do normal maintenance stuff on the truck, getting it up to normal par. That includes figuring out the 5th gear nut. I may put 2 nuts on the shaft, both with plenty of red threadlocker.

As far as the filters, I went with O'rielly (house brand) oil (15-40 petro) and a WIX (because they don't have fleetfilter, amsoil, or donaldson). In the future I think I will buy one of those brands online.

I have not thrown away the old filter yet, I want to cut into it and see what surprises it has for me... hopefully just a little bit of sludge.

Back to gearing. One of the things that needs to be looked at on this truck is the tachometer. It doesn't seem to want to talk to me: it sits at 0 all the time, and I have adjusted the ESS. I am slightly suspicious of the computer because my A/C compressor doesn't kick in.

2 things I need... after having a wiring diagram for my whole Jeep, I need the wiring diagram for my dodge. Also, I don't seem to have a factory repair manual.

[usergone]

Turns out that my truck has an old school fuel system... the fuel pump (lift pump) is on the side of the engine, not sitting in the tank. This means that it will be very easy to make a fuel cell to measure the FE of mods! This means that aerodynamic mods will be showing their improvements much sooner than with normal fillups.

[usergone]

My truck definitely needs some assistance in the paint department. The roof is about one summer away from surface rusting (more) and there are several places where the paint is chipping/rubbed off.

I bought a can of enamel "royal blue" and "aluminum" in hopes of trying to mix something vaguely close to the color it is now, for painting the sides of the bed. Originally I was going to paint the roof the same color, but I realized that I could paint it silver easier than I could match the blue. So, I will have an energy-efficient roof