Towing on vacation....

[Power Wagon]

Well, I just got back from vacation, after towing for close to 2000 miles.



I have some good, and some bad results. Good - man, that Cummins rocks... Climbed the east side of Stevens Pass, climbing the steepest part near the top at near 70, at 900 on the pyro (briefly, post turbo), with a 25 foot TT in tow.



Bad: Mileage sucks. I never got better than 14 towing, with results from 12 to 13 most of the time. Perhaps it's the speed. I have a tall "shell" on the back, that stands up more than foot straight up from the back of the cab, it's the fully enclosed kind. And then I was towing a 25 foot "lite" version of a travel trailer. The run up the Columbia Gorge home got me right at 13. I averaged higher than 70MPH, with lots of time doing 80 or close to it, and some higher.



There was a very nice Quad Cab 2500 towing an aluminum stock trailer (no animals seen), the long kind with room for 2 animals in the back, and sleeping and tack room in the front of it that passed me a few miles up the Gorge from Bonneville Dam. He was lead-footing it at about 80, and so I decided to let his red truck and polished trailer attract any cop's attention for me. I followed him to near Arlington, where, when we hit the first grade, I zoomed by.



Apparently, he must have believed it not possible to get outrun by a 1st gen, because as soon as we hit the flat again, he hustled up to me. I pulled over and slowed down as he approached, but, instead, he pulled in behind and followed.



When we got to the next long grade, he was right on my tail, and I decided not to show any weakness... Sure enough, as soon as we got to the steep part of the grade (a longer one, climbing out of the Gorge), I suddenly noticed he began to fade back, and then suddenly, he was WAY back there. I kept it right at 78 -80 all the way, and he couldn't come close. Following him was a new PSD pulling a 5er - about a 24 footer or so that I passed earlier, with a big "BANKS" sticker on the side. He tried, as well. He passed the QC, but never gained, but lost ground on me until after the hill...



Bad: Stock Converters SUCK!!!



With present and future plans consuming our funds for a while, no BOMB money for a converter. With the trailer in tow, anything below 60 or maybe even 65 on a grade, it was hard to tell the difference between OD and out of OD. Kicking it in just didn't slow the engine.



BAD: I need shocks...



What shocks have you found that are STIFF and stay that way under hard use?



Good: The beach was great, vacations are good. Just not quite long enough

 

[JFitzgerald]

PW, Glad you had a good vacation. IMO, that is decent mileage. I get 12-13 towing hard in hills, grossing about 18-19K. I'm sure you were lighter, but you were in the mountains, right? And doing 70-80 mph? I'm in the relatively flat Midwest. What were you expecting to get from your combo?



PS - I like hearing about a 1st gen being 1st up the hill, especially when it's in front of a PSD.

 

[Philip]

I don't think your mileage is off. With my truck on a long run with 7k in trailer and load. I got 14mpg with the cruse set at 70mph. I run out of motor at 75 with my 3. 07's at that wieght. Gross weight is around 15k. With the trailer empty at 80mph I run out around 17 mpg. But this is also on flat ground. With you running in the "Hills" you did good.



I hope you stopped the QC and gave him a TDR mailer to send in.



Sounded like the PSD needed one to.

 

[boatpuller]

Fuel mileage sound reasonable, my truck gets 10. 5-11 MPG towing my boat (around 7500 pounds) I travel 70-80 depending on conditions and try to never get passed by a Dorf on the upgrades

That is average from here to Lake Havasu, Arizona and to Sacremento California from here.

My mileage didn't improve when I advanced my pump but the power is higher and the EGT's are lower.

The mileage really hasn't changed with any of my mods, I just get there faster.



Happy Rammin

Caleb

 

[DBF]

For 17,000 miles last year - Virginia to Yellowstone to Alaska to Oregon to Virginia - our mileage was 12. 5mpg. This was mostly towing our 5er, which sticks up a lot higher than your cap. On the other hand, we weren't able to run as fast on some of those roads as you were running.



It will be a little better with a stiff T/C.



Still, if I try to get above 75 with the 5er sticking up in the breeze, it's like towing a wall. The wind resistance overcomes my foot against the metal right around 80. Then the trans temp starts climbing because the T/C is slipping due to the load.



There's always something limiting what you want to do, it seems.



DBF

 

[Power Wagon]

I'm really curious about how your 89% TC works for you.



I've driven a truck with that same fluid coupling (was also lockup), and found it didn't feel dramatically different from mine.



I understand the part about the converter and heating... . but actually, it seemed to me that the faster I went, the less "slip" I was experiencing in the converter - this was especially true in direct, while pulling grades at 60-70.



On a grade sufficient to hold me at, say, 60 mph at or near WOT, at that speed, switching between OD and direct would have almost no RPM change. Is that true of the 89% TC as well, or at that speed, will shifting into OD lug the engine down a lot?



I would assume that you don't have quite as much HP as I do, since I don't see any injectors in your sig, but the experience would be helpful.

 

[DBF]

PW, you're right on the horsepower. The Cummins dyno gives the beast 178 RWHP at 1750 rpm, due only to the pump tweaks and 16cm2.



The T/C is non-lockup, like the stock T/C.



The times I notice the better fluid coupling are acceleration from a stop, or in a passing situation.



With respect to the hill question, I see a large difference between Direct and OD. On a long 4-5% grade with the 5er I can go on up in OD at 65 or so (~1800 rpm - wouldn't try it at any lower rpm), but at some point the trans temp climbs & I have to turn off OD. The rpms go up dramatically, the trans gets more fluid flowing and everybody's happy, except I can't run over about 65. If I go back into OD, the rpms go back where they were (and the engine starts lugging if the grade is too steep). If I find a 6% grade, I just bite the bullet and get out of OD at the bottom, cause I'll just get hot and start lugging fairly soon.



I suspect part of the reason for my temp climb is that the radiator isn't clean; the engine temp climbs, which feeds back into the trans thru the heat exchanger with trans fluid. That's the next thing on the to-do list.



Perhaps what you're seeing between OD & Direct is that the T/C slips more when you load it more. I hope I've answered the right question.



Regards, DBF

 

[Bob Beauchaine]

Sounds good Mark - that's where my mileage and egt's are when I am towing my 28 footer. I usually set my cruise control at about 70 and sure enough they pass me on the straight's and I "cruise" past them on the hills. I know the area around Arlington well and if they can't keep up with you there picture them on some serious hills! You would be at the top of Cabbage hill before they hit the first turn

BTW will you be at Diesel fest in Spokane on Sept. 7 ? Hope to see you there.

Happy trails

Bob

 

[Tim1]

milage

On my trip to the dunes, I got 12 miles to the gallon towing a 30 ft travel trailer with the truck full of quads. Towed at 60mph in 5th gear this time at 19 lbs of boost at about 1100 degrees on the pryo at 1900 rpms with 3. 54s. I was concerned about the pryo temp as i could easily bury the boost at 30psi and run temp up to 1200 on slight hills. My pump is turned up and I haven't set the timing yet. I can live with the 12 miles per gallon as I have plenty of power now with the pod injectors. When I installed the injectors I used the . 093 washers like I took off, there was . 023 and . 065 also, have any of you fellas found that a different thickness washer effects the egts? Also, are all getrags hard to get into reverse? Thanks Tim

 

[NOMOFO]

Just drove with camper from Scotts Valley CA to Paonia CO. averaged just under 12. 5MPG. Camper loaded is probably min. 3600 lbs. In excess of 11' tall.

Quite windy much of trip. When safe, it was quite easy to maintain 70 but some long steep grades required me to back down to as low as 47 to keep pyro below 1200 which I chose to do. Also manually dropped out of OD when appropriate. That being said there always seemed to be more power available if I could've kept the temp down. Also should point out that I left the non wastegated 12 cm housing on as a test. Pump is tweaked, Fritz baseline more or less. Decided to try this after lengthy, helpful conversation with Al at PDR. Two major points of advice were to keep pyro below 1250 (pre turbo) and max boost below 32. I never exceeded 28 on purpose and was seldom above 25. Will change to the 16 cm before leaving as I want to see the difference and we will see much higher elevations on the return route down 550. Interesting stuff, guess this range is the ballpark. Wonder how if at all towing the load differs from carrying?

 

[NOMOFO]

DBF,

forgot to mention that I just changed my radiator. Bought a Valeo, (supposedly current Dodge OEM supplier) from 1-800-radiator for under $250 on the doorstep. Fit perfectly, and no problems in 1500 plus hard recent miles.

Backflushed block an filled with Fleetguard Compleat.

Interestingly they had Modine's available but said the rate of failures was more than triple the Valeo or Visteon in their experience. They have been good to me before so I went with their advice... .

 

[Ian]

Keeping cool

How do you guys keep your transmissions cool? My '93 D250 won't handle much over 10 lb boost without the transmission temp needle going past the vertical towards the 270 deg. temp. indication. Going down a gear ie selecting out of OD or from 3rd to 2nd and keeping the rpm > 2,000 and all is OK. Can take short bursts up to maybe 20 lb but the top of the hill better be in sight.



Been a long time since I was on the site.

'93 D250, 16 cm turbo housing, injectors upgraded, larger xmsn pan and it's filled with synthetic oil. External xmsn oil cooler with fan fitted. 5th wheel runs about 7,000 lb.



Ian.

 

[Bfulgham]

Ian:

If your Aux. transmission. cooler is like mine the fan is supposed to come on at 180 degrees. When my transmission. temps started going up I discovered the fan was no longer coming on. Routed around the sensor to a toggle switch and just flicked it on when temps approach 200.

Bob F.

 

[Ian]

Bob,

Soon after I had the fan and cooler fitted to the chassie just aft of the cab, I fitted a toggle switch and an indicator lamp. Toggle switch bi-passes the thermostat and the indicator lamp gets its power from the power wire right at the fan so I know when the fan is at least getting power. Also when I shut the engine off I can hear the fan slowing down.

One interesting quirk that did happen initially, with the fan running and shut the key off, the engine would continue to run for about 7 seconds. I'm not an electrician but I figured the fan was back feeding the system and keeping the fuel solenoid open briefly. A good size diode cured that problem.

Any comments on a cooler behind the front bumper?



Thanks, Ian.



PS As long as the going is reasonably flat, I can tow all day in cruise and OD at 100 km/hr, about 60 mph, 6 - 7 lb boost is average and I'll get about 14 miles per imperial gallon. Mark, I've been over Stevens Pass both ways, recently took Hwy 20 West from Collville to Burlington, a few tough pulls in there, also warmed up the brakes a bit. Nearly always I can hold the trailer in 2nd, not on parts of that road.

 

[BushWakr - RIP]

Ian,



I assume you've had frequent/full trans. service's done regularly.

One thing you can try is having the line pressure increase a bit.

The upper end is around 60psi. This will help a bit in reducing slippage internally. It will not be "holy cow" improvement.

Also it sounds like, to some degree, your at the point of "pulling thru your TC/Trans. You're just putting too much HP/Tq into/thru it with your mods.

Were is your tanny temp probe mounted? In the outlet line to the cooler or in the transmission pan.

1st Gens ALL ran/run hotter than the newer trucks. It was the nature of the beast.

On a hard WOT bonsai run I could crank the temps over 230*F + in seconds, while running empty.

My probe was in the outlet line at that time.

Since the drivetrain mods, I can do the same thing repeatedly and not see anywere near those temps. In fact it rarely moves off the 140*F mark now. BUT, my temp sender is now in the pan, since the darn outlet line fitting kept seeping/leaking. Last thing you need is to pop the sucker on a long drive.



Just some thoughts. .





Bob.

 

[Power Wagon]

There is a transmission cooler in front of the left rear tire, between the frame and fender... Is that factory? (the install is quite neat).



It is so unobtrusive that I never noticed it back there until i was doing the transmission service, and began wondering why the large hoses connected to the transmission ports went back there.



It has an electric fan (though I've never known it to run, at least not that I could hear), and apparently a heat switch back there to control it.



Maybe I can find some way of taking pictures...

 

[paccool]

Hi Mark



That is a Dodge option. I don't know if they were installed at the factory or the dealer. The paper work for mine says the cooler was installed at the dealer when it was delivered.



I've had the cooler kick on, just does it when towing the trailer.



Stan

 

[Midnite]

Originally posted by Power Wagon

Maybe I can find some way of taking pictures...

If you wouldn't mind, I would really appreciate that--I've been thinking about adding a cooler, and it'd be very helpful seeing a dealer install.



Mike

 

[paccool]

These are no longer made per several of the guys. There is another manufacturer that makes one just about the same as this, have seen sales literature on it. Can't remember the name but it was one of the transmission/oil cooler companies. Has a fan and thermistat just like the Dodge unit.



Stan

 

[DBF]

I still have the paperwork (15pp) for the installation of the SuperDuty cooler (p/n 82400994)(under the bed, with fan) from Mopar. There are drawings, but no pictures, and no dimensions.



If you *really* want it, I'll scan it and e-mail it to you (the files will be large). PM me if you do.



I quote from the front page: "This package was developed to provide additional engine cooling protection (sic) for our customers who wish to increase their maximum trailer tow rating from 12,000 GCW to 14,000 GCW, with a maximum trailer weight of 9,000 pounds or less, depending on the model. "



DBF