trailer aero
 

only have a few days to get this done...

i have lots of self taping roof bolts err i mean screw's
lots of 3/4" wood, and maybe more of the plastic sheets.

and i don't care what it looks like.:thumbup:


map of route


http://www.youtube.com/watch?v=HDih5...ature=youtu.be

I watched your video but didn't have any sound (my computer).

I would like to give a little aero help to my trailer at some point too.

A short tounge would help so the trailer can draft you better.

One thing I had considered is if I had a 2 axle trailer I would make it so I could pull the tires off one of the axels when towing empty or near empty. More tires more drag.

If the trailer is going to be open stack all the tall stuff toward the front. The front of the trailer is not as important as the back, unless its taller than your vehicle.

originally, it was a rear entry 2 horse trailer with tack room in the front.
the roof and walls had bad rust, and thus i made it a cargo trailer.

thus the axils are very far back compared to a avrege open cargo trailer, or car transporter...


having the axils so far back, helps in side winds quite a lot and is very very nice in sustained side winds.
but with a smaller tow auto, it limits how i load it, and how much load quite a bit....

to hall a small/mod size auto.
it must be loaded back words, to put most of the load on the trailer, and not the tow auto.

but for this trip, i will be on the light side. just my bio fuel and mabe some parts to sell.
only the tank pump and barrel will be higher then the front rounded part of the trailer. i can see over the trailer with my rear view mirr

im thinking about cutting and using the plastic, to cover the out side of the tires, more or less boxing them in.

1: Do not shorten the tongue. Too much work, structural, low payoff.
2: build a splitter for it instead. use metal or lumber, build a triangle at same height as front of curved front, and use two panels as sides. Now the crosswinds will not cause as much trouble there.
3: build simple three panel boat tail for trooper, that goes back 4' and is above that splitter with a safe clearance for odd driveways, etc. let's say 6"
Angle it at 12 degrees down and in on sides. More than that and it will separate.
This will manage the flow off the trooper, reduce the trooper's wake, and deliver it onto #4
4: roof over trailer as you planned. curve it down slowly all the way back, and make it open up where you need. Even if you have to grab the screw gun to open it up, finish it off as smooth as you can.

Anything else beyond that will be of limited return. I would not bother covering the trailer wheels, when you look at the running board construction and other things that are already crapping up the air there.

See splitter detail below. three pieces of metal/wood, two panels. Leave top open unless you have panel material to spare.
Now it will work more like this motorcycle trailer in the second pic.

for the time that the trailers being pulled, would removing the air deflecter on the top rear of the trooper help much :confused:

was thinking i mite help maybe, just a thought.

I'd pull it and mount the boat tail on those mount points.
turn the tank lengthways. this will let you curve the roof in on the sides. any tumblehome you can do is money.

ok thank you, now ive got some ideas.

ill see what i can do.

sent you a PM

* Put a splitter plate on the tongue to reduce crossflow between the towing vehicle and trailer. Could be a V-shape, or even a single vertical plate.

* Cover the wheels

* Build up the sides to the height of the front, and put a roof over it, at least as far aft as the fuel tank.

* if you can't make a roof, try mounting the fueltank lengthwise rather than transverse - frontal area will be a lot lower


In the long run, if you want to keep the trailer, moving the axles forward will increase its usefulness - unless you use it for very specific purposes that can take advantage of the rear axle position
(like transporting heavy gardening equipment, small crane , ... over the axles with the lighter stuff up front).

Aero wise that rounded nose left from the horse trailer is about as good a start as you can get. You could build sides up to template. I'm not sure of the trip purpose or how much weight goes on that trailer. Seems like a lot of tongue weight. If one set of axles would suffice maybe remove the rear one for the trip. That would bring tongue weigh down. With a template shaped profile there would be more cargo space up front so the hitch might not be overloaded. Hard to say really. I feel like I'm missing a lot of context...

great idea Bob, or even better, remove the tires only. This will help shift weight off the tongue.

i have thought about pulling one hole axil, but this thing was made to have a steel roof its hole life, and not have the frame take all the stress.
i think it would be like bending a pace of tin back and forth, sooner or later it will give....

some photos of when i made it a cargo trailer. starting 2/3 of the way down the page....
IsuzuPup.com • View topic - any intrest in parts at East Coast meet ?
i wanted to leave the sides at 3 foot all around it, but the sides made the trailer twist, shake, vibrate quite badly, so i lessened them.


its common for me to carry super local hay loads, so i have been toying with adding maybe 5 feet to the rear of the trailer.
to lessen the tunge load and make less trips....

also this would let me get a home made title for it, since i would have papers showing i had put steel in to it. and more or less reconstructed it in a manner of speaking.
a legal way to make a trailer home built in OR state.

its a deal where 3+ people have had the thing thru the years but no one transfers the title.
it has never been registered in my state, thus i can not apply for a lost title.
when i got it it was a rusting heap of junk that the guy wanted gone NOW!!!
i made him sell it for $1.00....so when dealing with WA state they could account for the 0.07c tax other wize it would have been FREE

i just got the trip permits to day for the drive, LOL the DMV is like wow what on earth are we going to do LOL

Why would it ?
The trailer tilts around its front axle.
Removing anything from behind the front axle, will increase tongue weight.


If the intended load allows for it, move the fuel tank aft over the wheels.
If possible at all, move it to be near the rear axle.

Looking at the trailer pics in that thread, run a continuous beam down the centerline, and put a diagonal brace in either of the squares that you have made this way.

http://www.isuzupup.com/download/fil...3646&mode=view

I hope the beams on the left and right that make up the towing tongue / triangle, are running aft for the entire length of the trailer ?

If you want to lengthen it - and carry more weight - why not double up the lengthwise beams while you're at it ?

yes the steel runs all the way from the tung to back to the front of the tires.

just ran it over the plug and play scales on the high way with no real load.
1,600lb trailer and 150lb tung load.

but with some where around 160 gal of cooking oil, it was 2,900lbs on the trailer and 4,800 on the trooper.
a staggering 600lbs tung load, sence the trooper is 4,200lbs with a full tank and me in it.
the load transfer bars put best i can guess 150lbs+/- of that on the front axil of the tow auto...

that was with two full drums in line with the frunt axil, and two half full drums just in front of them, looking at that photo, two drums are right behind and two are right in frunt of the steel cross peace that was the wall divider for the horse area, and 20gal in plastic jugs up in the aro nose

any way the moral of this is, it gives me a good base line as to how to load it for the long drive.

the scale runs on 50lb jumps so if it was 2,949lbs it would read 2,900
at least that's what i under stand.

taking rear tires off removes that force upward there. pivoting around the remaining axle, this acts to remove tongue weight. Leaving the rear axle in place without tires, removes even more tongue weight.
This of course lowers the carrying capacity, and might induce less than friendly tracking, bounce in the bumps, etc.
Typically, two axles track nicer, have less tendency to bounce, less tendency to lift and lower the tow vehicle (TV) because the tongue weight is more stable. Downside, more parts to replace, tires, scrubbing during tight maneuvering.

horsetrailers OFTEN use the sides of the trailer for strength. I'm not very impressed by the "frame rails" which run fore and aft. If it were mine, I'd add something, or put some sides back on.

600 pounds tongue weight is not that much. The hitch and truck should be just fine with that much.

a MINIMUM of 10 percent of the trailers weight needs to be tongue weight. A MAXIMUM of 20 percent is recommended.

You are within those guidelines.

Not enough tongue weight leads to trailer whipping and someone dead. Too much makes your truck squat, but it takes a LOT of tongue weight to affect the handling.

Given more context I hereby withdraw my suggestion to remove rear wheels. (It's actually an advanced move given leaf spring equalizer pivot mechanism.)

Tangent on tongue weight. The ad-hoc 10% rule in the US is less (5-7%) overseas. Hucho's section on caravans touches on tongue weight. One explanation is typical trailer geometry when nose/tail pressure effects are taken into account. Think about it. If surface normals intersect the axle pivot then tongue weight stays constant; whereas with boxy trailers front push and back pull takes weight off the tongue as speed increases.

Sorry, but it doesn't.
The trailer is already front-heavy as it is.
So it pivots around the front axle.
Anything behind the front axle is acting as a balancing weight, so removing it puts more weight on the tongue.

Being so front heavy, 600lbs on the tongue means it's unloading the rear axle, and putting a lot more strain on the front axle. What's the use of a double axle then ?

This trailer was obviously designed with the weight of the horses in mind - that's a lot of weight, but they were situated right over the wheels.

I'm always surprised by statements like
600 lbs on the tongue is a lot.
Sure it's a 4x4, but still.


On this side of the Atlantic, most passenger cars allow with 100-150 lbs, some 200lbs on the hitch. We don't use special sway gear, or special bars to move some of that weight forward on the tow vehicle, and yet we tow more trailer weight with passengers cars than what's allowed in the US.

While a positive downforce on the tongue is good to control the tow, and keep it from unloading the rear axle of the towing vehicle, there's no need for excessive tongue weights.

draw a force diagram. put 2200 pounds on both axles. Remove back axle. Moves force forward. reduces tongue weight. I will devote no more to this post than this post. If you are unable to see that I cannot help you further.
Edit: the weight of the tires and axle rest on the ground. Now that axle hangs off the frame too. See where this is going?

would you by any chance know what the tow rating of GEN1 troopers 1984/1991 are in your country.
unless there all rusted out where your at, from road salt.

there's very little info on them for towing rating in the US all i know is there rated at class I likely do to the rather low hp numbers...

best i know, Isuzu really did'ent even want people to tow with them at USA road speeds...

10 to 20 percent is the standard. Less than that and you will kill someone, hopefully yourself.

There is no need for that kind of comment.

hmmm......

Well, when his trailer and truck starts whipping back and forth, and he crosses the center line and head on collision with someone else, someone is likely to die.

And, it doesn't seem very fair the other people should die, and he should live.

So, my point is, if he is going to be a dumbass and endanger other people, and someone dies, I hope it is him, and not some poor innocent person who was in the wrong place at the wrong time.

Having less than 10 percent tongue weight is DANGEROUS. PEOPLE DIE.

12-15% tongue weight [TW] is the RV standard. Less than that isn't as effective, and up to about 18% is good (old SAE papers).

A weight-distribution hitch [WDH] is the requirement by the big automakers even on one-ton diesel dual rear wheel pickups past around 350-500 lbs TW. TW is not static . . that lever arm extending back to the axles can exert many thousands of pounds of force in adverse circumstances. A WDH has two jobs:

1] Restore the Front Axle to it's unhitched weight when activated.

2] "Distribute" the remaining TW between the tow vehicle and the trailer.

The effect is to keep the steering (especially) close to stock vehicle feel/action (some level of understeer), and for braking & handling otherwise to remain close to stock.

The addition of weight to the trailer axles helps that vehicle as well, especially in braking.

A 600-lb TW might wind up as 150-lbs back onto Front Axle, and the remaining 450-lbs spread between Drive Axle and Trailer Axle as 270-340-lbs on Drive Axle and the balance back to the trailer.

Obviously, a tow vehicle drive axle carrying around 300-lbs trumps 600. But the Steer Axle not being lightened is the key.

And, yes, a well-sorted WDH will certainly help mpg . . less movement inside the lane, less reaction to crosswinds, etc.

The addition of anti-sway devices (the right ones, not the old friction bar type) will definitely be noticeable.

There is new design in WDH hitches, and it's simplicity is appealing:

Andersen WDH

An apt discussion here.

That and LT tires (not ST tires: unacceptable failure rates on tires made on obsolete equipment [is the current surmisal]) would be high on my list for reliable trailer performance behind such a marginal tow vehicle (tall, short wheelbase and underpowered).

Same for a TEKONSHA P3 Brake Controller (at minimum). That's one helluva long trip.

Trailer tires should always be at cold sidewall maximum pressure. That and lug nut torque value is what I check before ever moving the trailer. Every time.

Trailers have a tendency to want to pass their tow vehicle. However well loaded they'll move around quite a lot in the lane. A good WDH damps this tendency greatly. It's noticeable at the steering wheel and at the fuel pump.

Lessened driver fatigue is the real MPG secret, and WDH plus best brake control adds immeasurably to this.

.

How does a WDH compare to something like the ProPride or Arrow hitches?

WDH = Weight Distributing Hitch
Propride and Arrow/Hensley are brands of WD hitches.

So they all work the same way? Wouldn't one of the more expensive ones eliminate the sway?

weight distribution is the big benefit.There are other systems that couple the weight distribution with a hydraulic dampener.
In the end, you still need to be able to turn. If it can turn, then a combination of bad bumps and bad pilot input can get things going.
In the aviation business we call this Pilot Induced Oscillation (PIO).
A seasoned driver can keep things in check. A rookie can fudge it up with the best equipment.

WDH -- weight distributing hitch[es] -- are available at several tiers of anti-sway control capability. PULLRITE, PROPRIDE then HENSLEY are the top tier, REESE Strait-Line / Dual Cam, then Equal-I-Zer are the second (with the new ANDERSEN), then the old (and unacceptable) "friction bar" antisway add-ons to cheap generic hitches.

Please don't think "experience" matters much. I'll put mine against anyones (type, variety, terrain, trailer type, miles travelled, etc). It's good for knowing what to do when a tire blows . . on a steep downgrade being passed by semi-trucks (always a bit hairy) . . in any number of ways that matter, experience is a good thing. But it is trumped by these latest hitches (about 15 years now) for the "elimination" (a manner of speaking) of trailer sway, incipient or dangerous.

I might wish my children learn to drive in a slow old pickup with manual steering, brakes and transmission. Tall, tippy tires. With me aboard guiding them in how to deal with the vehicle. But I'd want them running the highways in a well-sorted Camry (or the equivalent) with best tires and book maintenance, etc. Same for a tow rig. The dynamics need to be experienced to find out how little one can actually do (in accident avoidance) to drive home the need for certain principles to apply first.

One can make the same arguments about bias ply tires or drum brakes versus radials and disc brakes . . at the end of the day "experience" is a code word for "testosterone" if it is put as a substitute for best equipment (best engineering) and excused as a matter of "too much money" for the better equipment (ridiculous versus the value of the combined rig).

Towing accidents are often lumped under "driver induced loss of control" which means the two vehicles are trying to head in separate directions (jack-knife, for instance) and some hitches are much better at heading that off in the first place (would be the point). In the same way would we want our family in a modern vehicle with state-of-the-art design and devices . . and the skill to not have to use them.

A margin for error that favors the moments inattention.

.

I disagree. Folks need a little training, and I stand by my statement. Without it they are an accident looking for a location. No WDH will save them from a lack of experience.

"Training" was already stated. But there is no substitute for best equipment (which also means hitch rigging set up according to formula). Anyone, novice or pro, is better off with such in any and all cases.

I did not find training stated.
Not all of us were born backing a trailer and hauling a load, as did you and I.
That is my main emphasis. All the fancy equipment on the most modern trailer is worthless with out that. IF you are within your hitch requirements of the tow vehicle, and have a properly loaded trailer the WDH is a great convenience but not a requirement for safe operation.
Note the hitch requirement statement. Most rigs come with a standard class 3 with 500 tongue/5000 maximum trailer weight WITHOUT WDH.
So following your class 3 standard hitch requirements, you will have a WDH with a typical travel or car trailer.

" . . Same for a tow rig. The dynamics need to be experienced to find out how little one can actually do (in accident avoidance) to drive home the need for certain principles to apply first."

well i managed to get home.

ive had many exciting things happen on this trip.

like oh little things like a fan belt, water in fuel warning, WVO short fall, severe side winds and head winds felt like gust to around 70, 105F heat with very high humidity (no A\C):eek:, axil shaft sliding out. you know little stuff like that....:cool:



ive found one of the best safety devices is your hazard lights.
just slow to 40/45 and go with the hazard lights



Planetisuzoo.com • View topic - Planet member broken down & stranded

IsuzuPup.com • View topic - daves grand adventure, June 2012

Read the links . . quite an adventure. Bet you won't be moving to the South, willya?

No way!!!!

Ill take damp dark and rainy over that any day.....

Seems like you two were a good match, one mad enough to take on this kind of trip, and the other mad enough to come to the rescue of a stranded stranger he had never met, hundreds of miles away.

Nice one :thumbup:


What made the rear axle fail ?

what made if fail is rather odd, and i dont under stand it totaly.


i know i found the vent tube completely plugged, mix that with the added stress of towing the high temps and a tale pipe leaking a good 20% around the axil that made the oil seals fail on the axils.
the oil just takes the path of least Resistance.


but how that made the axil shaft come out is very odd.
the only thing i can come up with is, the extra high temps let the locking nut get loose, thats the only way for it to come out is for the locking nut to come loose.

or just by random chance it just happened then.:confused:

glad you made it back! Still reading the adventures......