Ecodiesel towing test. Suspension sag, mpg, power, and cooling

[NIsaacs]

It might not feel different but the physics says it has to be.

I agree, a pickup already has too much overhang. The shorter the drawbar the better the control. You are on the right track. Not knocking your pickup because it is a dandy, but lets face it, it is a 1500 so you will have issues to overcome the bigger pickups don't. Buy a new bit and finish drilling that 5/8 hole you started

Nick

 

[JR]

A cobalt bit and some cutting oil will chew right through it. The typical over the counter bits are junk these days.

 

[RangerGress]

A cobalt bit and some cutting oil will chew right through it. The typical over the counter bits are junk these days.

I'm 51 and came out of school as a mechanical engineer. I've done at least as much light machining and fabbing as other males of my generation. That said, I'd have to say that until this project I really didn't appreciate the fact that you would seem to be exactly right. I did not really understand just how much over-the-counter bits suck. My only bit that made it right thru the steel shaft was a 1970's bit that I inherited from my father. It was far smaller then I needed, but the fact that it punched thru helped the project.

I'm going to start watching Craigslist for some old-timer selling drawers full of drill bits from the 50's and 60's. Back when real men ran lathes, not notebooks.

 

[RangerGress]

Success. Since these big bits are too large for my little drill doctor, I watched some youtube videos on sharping bits on a bench grinder. That went pretty well and my sharpened bits finished the hole in the shank. Excellent.

Left hole is 11/16th thru 2" of fierce Harbor Freight steel. That was the most serious hole I ever drilled.
#ad

 

[crispyboy]

^^ Hitch head should be vertical! SNOKING

Actually the hitch head could be vertical but would serve a better purpose if tilted downward. This is so you can get more upward lift on the bars if needed and when you go around a bend in the road it does not unload the front end of the truck - thus the front tires would have less traction in a turn.

 

[RangerGress]

You guys are really wrapped up in the ball orientation. As long as the WD bars are good and tight, the ball being a little off vertical matters how? It's a sphere, it doesn't know about angles. Seems to me that the orientation of the ball doesn't have any connection to the "moment" on the WD bars. If they are tight they are tight.

 

[Bob4x4]

It's not about the ball but it is easier to use that to judge the angle that the bars enter the ball mount that will determine how much preload can be applied by the bar adjustment.In your picture the bars are up tight against the trailer tongue with what appears to be no flexing of the bars

 

[RikDavis]

The point is to tilt the head so that there is a reasonable amount of chain available when the bars are tensioned properly and still allow the ends of the bars to move as you turn. The ball angle just happens to move with the head. I think when people are talking about the ball angle they are just using it as a reference. As others have said, the head needs to be between vertical and slightly tilted to the rear.
If the head tilts forward (as in the pic) there is not enough chain available to tension things properly.
The starting point is to get enough tension on the bars to get back around 1/2 of the rear end sag that you got when dropping the trailer on the ball and then refine it from there if need be. Of course the hitch head height should be adjusted to obtain a level trailer as well. Sway should not be a problem if everything is set up right but you do have the option of adding a friction sway control if needed

 

[RangerGress]

The point is to tilt the head so that there is a reasonable amount of chain available when the bars are tensioned properly and still allow the ends of the bars to move as you turn. The ball angle just happens to move with the head. I think when people are talking about the ball angle they are just using it as a reference. As others have said, the head needs to be between vertical and slightly tilted to the rear.
If the head tilts forward (as in the pic) there is not enough chain available to tension things properly.
The starting point is to get enough tension on the bars to get back around 1/2 of the rear end sag that you got when dropping the trailer on the ball and then refine it from there if need be. Of course the hitch head height should be adjusted to obtain a level trailer as well. Sway should not be a problem if everything is set up right but you do have the option of adding a friction sway control if needed

Ah so.

Folks might be misinterpreting the pic. The WD bar-end has 4 chain links from the fastening point so there's plenty of room for the bar to go up if the trailer tried to porpoise. Turning doesn't cause trouble because the WD bars pivot at the ball so they are free to turn with the trailer.

Thanks for the explanation on how to set up the WD bars. I'd not read something like that before. When I first starting using WD bars 3yrs ago I hooked them up as tight as I could w/o using the trailer jack. Then I went to a scale and found that the WD bars were only moving 30lbs from rear axle to front. That didn't hardly seem like doing.

Then someone told me about using the trailer jack to lift the center of the rig prior to hooking up the WD bars. That allowed me to get the bars one chain link tighter. This new set up moved ~100lbs from rear axle to front, still not a lot but that's 200lbs of total shift. So that's how I ran the bars for the years that followed. Use the trailer jack and get the bars as tight as I could. Not much calibration about it.

Sway hasn't been much of a problem. The scales allowed me to set the tongue weight by positioning the race car inside of the trailer. So I just set it in the same place every time and I get a tongue weight of 11-12% depending on fuel jugs and spare tires in the trailer. Since it's easy to change trailer weight, it's easy to deal with sway. Also, I think that WD bars have an affect on sway. Looking at the geometry of the bars, I think that when the rig goes off-center, the bars are put into more bending moment. Not as much as the cam designs, but still some.

It's still hard for me to buy tho that the ball "should" be tilted to the rear a bit. The WD bars need to have a bending moment on them. It seems to me that can be accomplished just fine with the ball vertical.

 

[MLee]

5 degrees is what is recommended by the experts. Which translates to the proper angle for the bars for proper WD hitche up. But you knew that all already right?
That type of hitch should have a bolt with some washers added to help achieve and hold the proper angle, not just through the elongated holes in the receiver part which it looks like to have.
Not nit picking just looking. With all this advice your on your way.

 

[RangerGress]

That type of hitch should have a bolt with some washers added to help achieve and hold the proper angle, not just through the elongated holes in the receiver part which it looks like to have.

Yes, it has the washers to set hitch angle.

I think we've beat this one to death folks. Per the first post, the droopy hitch ball was just an intermediate experiment as I played around adjusting the hitch for the new tow vehicle. Can we get back to how fabulous the truck is?

I got 28mpg driving to work yesterday. The truck is so quiet I can't hear the engine at all. I've been playing 70's and 80's tunes on satellite radio. Even tho I'd poured (foolishly) a mess of $$ into the F-250's stereo system, I never used it. The track was already so damned loud that the last thing I wanted to do was raise the volume level even more.

Mostly I'm just amazed at how sophisticated and luxurious the truck is. The difference in interior between my 2000 F-250 and my 1988 BMW isn't hardly anything at all. But the interior sophistication and luxury delta between the 2000 truck and this 2014 truck is incredible.

There's no question that the rear springs are kinda weak. Theoretically I can put almost 1300lbs into the truck, but I put 800 on the hitch and the rear sagged 3" and the front up 1". That seems like a lot. If I had more trust in the airbag suspensions, I'd have gotten that instead. I guess the lesson learned is that if a person is going to put a serious load on the truck, either get the airbag suspension or put airbags in the rear springs like I did.

 

[Joseph Donnelly]

Depending on winter or summer fuel, mountains, etc. my 3.42 geared 3500 gets 11 to 12 mpg with a similar box trailer at 72-74 mph.

 

[DonFitzwater]

I was also surprised by the coolant temps while towing with my 2010. The newer the engines, the hotter they run. I wouldn't be concerned at all with the temps you are seeing. What kind of trans temps are you running?

As mentioned before, use tow/haul. It will move shift points to make acceleration better under load and also add some engine braking (just assuming the last part as every dodge truck I've owned has done this in the past)

I'm very impressed with your towing numbers. The next door neighbor has an Ecoboost and he gets 10 mpg while towing a 2k pound boat so you are getting 50% better fuel economy while towing a heavier trailer AND in more comfort.

 

[RangerGress]

This guy says our turbo is watercooled and the tstat doesn't fully open until 228deg.
http://www.airforums.com/forums/f238/2014-grand-cherokee-eco-diesel-115460-12.html#post1449120

If that's accurate then my coolant temp wasn't that high after all.

Re. the Ecoboost. IMO they got too much press. It just seems to be slightly more efficient at everything vs. a V8. It's no diesel baby. <--channeling Austin Powers.

 

[Ozymandias]

That's what we said, your temperatures are fully in range.

 

[DonFitzwater]

Airforums.com was full of dorks...........people that question everything and understand nothing. I'll never go there again!

 

[RangerGress]

That's what we said, your temperatures are fully in range.

I hear you but "don't worry about it that's normal", isn't the same as "don't worry about it that's normal because your turbo is watercooled."

Good info is always appreciated. Can be hard to separate the good info from the BS tho. Yesterday I had a guy trying to tell me that hitch shanks were made of hardened steel. He didn't know hardened steel from lasagna.

 

[AH64ID]

I hear you but "don't worry about it that's normal", isn't the same as "don't worry about it that's normal because your turbo is watercooled."

How does having the turbo water cooled make one bit of difference on the normal coolant temp?

I fully understand the benefits of a water cooled turbo, and run an aftermarket one, but that statement doesn't make any sense.

It's normal, and it would be normal even if you didn't have a water cooled turbo.

 

[NIsaacs]

I don't have any water cooled turbo's so I don't know, but maybe the OP's thought was it was another heat source that adds to the coolant temp. Such as engine oil, auto transmission, intercooler and power steering cooler, if it has one.

Nick

 

[RangerGress]

How does having the turbo water cooled make one bit of difference on the normal coolant temp?

I fully understand the benefits of a water cooled turbo, and run an aftermarket one, but that statement doesn't make any sense.

It's normal, and it would be normal even if you didn't have a water cooled turbo.

My assumption is that the engine coolant is being used to cool the turbo, no? As long as that's the case, then it's easy to imagine that with significant additional heat load coming from the turbo, the engine cooling system would be designed to tolerate much higher temps then we are used to. Since it's easier for me to understand high coolant temp now that I understand the turbo to be in the circuit, knowing about the turbo being water cooled makes a difference to me.

It's still kinda spooky tho. Trying to use water, with it's low boiling point, to cool something as hot as a turbo is kinda surprising. It would probably be less surprising if I knew anything about turbos. Sure, water under pressure has a higher boiling point, but it ain't all that much higher. Local hotspots are sure to cause microboiling which can cause all sorts of issues like pressure spikes and maybe even cavitation. Pressure spikes in a cooling system are bad.

Sure, the cooling system was designed to handle the turbo's heat, continuing the assumption the turbo doesn't have it's own separate cooling system, but that doesn't mean the design was a good idea. If indeed the thermostat is fully open at 208deg, then after that the cooling system's ability to manage it's temperature is gone save only for the increasing efficiency of heat xfer at higher temp deltas. Coolant temp ~15deg higher than tstat temp isn't something to get excited about, but on the other hand it was a pretty mild test.

If, on the other hand the turbo does have it's own cooling system then I agree that engine temp wouldn't be related. I'm used to 80's BMW engines which are infantry-simple. The complexity I see when I open the Ram's hood, that not covered by plastic, is pretty bewildering. I don't know that I can figure out how the turbo is cooled with just a casual inspection. The two coolant systems could certainly share the same radiator yet remain separate circuits....it's common enough for oil and transmission coolers to be integrated into the engine's radiator.

Later edit. The tstat #'s above are wrong. Fully open at 228deg, not 208deg.