Go Back   EcoModder Forum > EcoModding > Aerodynamics
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 04-11-2010, 01:10 PM   #71 (permalink)
Banned
 
Join Date: Oct 2009
Location: Fort Worth, Texas
Posts: 2,442

2004 CTD - '04 DODGE RAM 2500 SLT
Team Cummins
90 day: 19.36 mpg (US)
Thanks: 1,422
Thanked 737 Times in 557 Posts
I have a weight distribution hitch with 1 sway control. It is set up per instructions. What setup were you referring too and how would one of those other hitches help over what I have?
__________________


For me, the gold standard is a sway-eliminating hitch, disc brakes at all wheels of both tractor and trailer, and fully independent suspensions.

That hitch type does literally that: eliminates sway. The trailer is forced to track the tow vehicle. The difference is night and day . . . and before you or anyone tries to tell me [you] have "no sway problem" I guarantee I or anyone else can follow you down the highway, videotaping, and show you the literally-beyond-counting number of times the tow vehicle and trailer are not tracking the same. It may be minor, but mile-after-mile it really adds up.

A friction bar controller is junk. It requires you to de-activate it when in rain or slippery conditions. Etc. The next best step up is a REESE "Dual Cam" (lesser, "Equalizer" brand), but it does not eliminate sway. Only PULLRITE, HENSLEY and PRO PRIDE do. The trailer CANNOT change direction until the rear axle of the tow vehicle "tells" it to.

Bear with me as I go off topic to back into "best practice" in regards setting up a weight distributing hitch. One will need before & after weight scale readings, as well as before & after height measurements on trailer and tow vehicle. Economy is working the margins, the ones all over the place, where the trailer and tow vehicle are givens. I apologize for being so late in replying, as what is below is but part of a 50+ page .pdf I can send with your email (anyones) with about as many links. It isn't yet complete, but I have pulled together as much as possible for the present. (And there are links which have no real bearing on economy, but are related to towing concerns nevertheless).

Below is a partial section about WDH hitches, and most of the section on brakes. Being able to run the roads with two-fingers on the wheel (so to speak) is a big difference in "safety", and definitely a margin-improver in being able to predict rig behavior while on the road in winds, commercial traffic, etc (half the fuel economy battle IMO, as trailer, tractor and speed are already determined. What happens next are all the small, tiny adjustments in driving skill).

As a businessman these expenses will be deductible, and I realize that commission sales is a roller coaster, so start your search early. Contact those companies for re-furbished units. (And, as a side note, I've been advocating the use of the HUNTER GSP-9700 for over a decade to others.)

---------------------------------------------------------------------------------------

(Ron Gratz over at rv.net)

Weighing #1 -- TT attached and Weight Distribution Activated

Let Front Axle Load be "FA1"

Let Rear Axle Load be "RA1"

Let TT Axles Load be "TT1"

Then, while in same position on scales, take
Weighing #2 -- TT attached and Weight Distribution Not Activated

Let Front Axle Load be "FA2"

Let Rear Axle Load be "RA2"

Let TT Axles Load be "TT2"

Then, drive off scales and drop TT. Return to scales and take
Weighing #3 -- TV only -- TT Not Attached

Let Front Axle Load be "FA3"

Let Rear Axle Load be "RA3"

From the above values, you can calculate:

TV weight = FA3 + RA3

Gross Combined Weight = (FA1 + RA1 + TT1)
- should also be equal to (FA2 + RA2 + TT2) if scale weights are correct

TT Weight = Gross Combined Weight - TV Weight

Tongue Weight = (FA2 + RA2) - (FA3 + RA3)

Load Transferred to TT Axles
when WD System in Activated = TT1 - TT2


HOW DOES A WDH WORK?
RV.Net Open Roads Forum: Towing: Weight Distribution (WD) Hitch --- How it Works

http://www.trailerlife.com/images/di...wGuide0801.pdf


TONGUE WEIGHT
Tongue Weight


SHERLINE PORTABLE HITCH SCALE
Sherline Direct: LM1000/LM2000/LM5000 - Sherline Trailer Tongue Weight Scale


FORMULA CALCULATOR
Travel Trailer Weight Calculator


(ignore "safety margin" shown; it is incorrect)

LOAD DISTRIBUTION HITCHES: AN ANALYSIS
Load distribution hitches-an analysis - Page 5 - Airstream Forums


One can estimate the forces on your rig after hitching but BEFORE using a weight scale. Take these measurements for above .xls download link. (Link download optimized for the "traditonal" 1/3-1/3-1/3 TW distribution onto axles).

1. Trailer length, hitch center to rear bumper:

2. Tongue weight:

3. Tow vehicle wheelbase:

4. Rear spring capacity:

5. TV rear overhang (axle center to hitch ball center):

6. Hitch center to TT axle center:

7. Length of bars:


Prior to hitching, each vehicle must be level within itself. Hitch ball height is set from this point as are adjustments to the hitch head, so, find both level concrete and use any device to determine "level" in the direction of travel and crossways to that. Obviously, tire pressure must first be perfected (see owners manuals and manufacturer statements; top sidewall pressure is NOT correct AND can make things worse).


Adjust the hitch ball height to 'level' the trailer

Adjust the weight distributing bars to 'level' the tow vehicle

Adjust the hitch head angle to 'level' the bars.


"The amount of load transferred to the TT's axles is a direct result of how much upward force is applied to the rear ends of the WD bars.

The amount of load transferred is equal to the total upward force applied to the two WD bars multiplied by the ratio of effective bar length divided by the distance from the ball to the midpoint between the TT's axles."


Manufacturer instructions are meant to be easy to use, not exhaustive. Example:

Ford (since 1998; research for current info):

2] Measure the height of a reference point on the front and rear bumpers at the center of the vehicle.

3] Attach the trailer to the vehicle and adjust the hitch equalizers so that the front bumper height is within 1/2 inch
(13 mm) of the reference point.

4] After proper adjustment, the rear bumper should be no higher than in Step 2.


Sway Eliminating Hitches

The best hitch is the current Jim Hensley design, PRO-PRIDE (company run by Sean Woodruff)

ProPride, Inc. Trailer Hitch - The Next Generation in Trailer Sway Elimination


I have the earlier generation, the HENSLEY ARROW (different company), but it suffers from lack of true weight distribution capability. The hitch you have now, and all others (except PullRite) make claims to dampen sway. The above eliminate trailer sway. You'll be fingertip driving once set up (assuming you have done the above work of WDH set-up with before/after scale readings). Worth every penny, ESPECIALLY for a businessman. Believe me that no one EVER goes back to an inferior hitch.

UNOFFICIAL PP USERS GUIDE
the unofficial pp users guide... - Airstream Forums

You can also look into PULLRITE hitches if your truck has high ground clearance AND can handle an additional 500-lbs of hitch/receiver weight.

PULLRITE
PullRite has a SAFER, STRONGER, BETTER designed hitch for you

The price of all these hitches when new is comparable. Used models are available from companies, and on CRAIGSLIST, E-Bay, etc. Shipping weight on first two is above 200#.

For a pole trailer buy a WDH adaptor:


Trailer Brakes

Next is trailer brakes. I have yet to see drum brakes properly wired for maximum voltage/amperage potential at each wheel.

One wants the maximum amount of juice to each brake, and evenly (no pulling). That is a matter of both electricity available and mechanical brake adjustment (plus bearing adjustment). "Perfect" brakes mean minimal amounts of application to remain
Lane Centered.

One of the major findings from 2006 "Towing Troubles: Danger on America's Road" study was that more than 50 percent of towing vehicles and trailers received moderate or poor rankings on their electrical systems. This suggests that brake lights, turn signals, and reverse lights may not work properly due to frayed and exposed wires, which pose a significant danger and are a contributing factor in accidents.


John Barca (JBarca) on RV.net recently upgraded his trailer brakes with an excellent writeup/photos, and the wiring job is outstanding:

DEXTER SELF-ADJUSTING BRAKES
RV.Net Open Roads Forum: Towing: Dexter Self Adjusting Brakes (long W/pics and details)

BRAKE WIRING DIAGRAM
http://www.championtrailers.com/Elec...l%20wiring.pdf

BRAKE AXLE WIRES
Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Hooking up brake axle wires

WIRE UPGRADE FOR TRUCK
RV.Net Open Roads Forum: Towing: Independent Brake Wire Feed Upgrade

WIRING PLUG
etrailer.com | Trailer Wiring Diagrams

MAGNETIC 7-WAY TRAILER CONNECTOR
EZ Connector Trailer Plugs - Waterproof, corrosion free trailer plugs
"Do your Trailer Lights Work, EZ-Connector magnetic trailer wiring connection 7 pin RV trailer plug that is water proof, corrosion proof, the last trailer plug you'll ever need."

TATTLE-TRAIL TOWING MONITOR SYSTEM
Trailer Towing Monitoring System - Trailer Accessory - Home

Trailer lighting (Modulite)
http://www.dieseltruckresource.com/d....html?t=242893

Trailer Anti-Theft and Wiring Correction
Trailer wiring basics for towing

Generic Brake Wiring Diagram
http://www.championtrailers.com/Elec...l%20wiring.pdf

Brake Inspection
Dodge Diesel - Diesel Truck Resource Forums - View Single Post - Trailer brakes


("JELAG" on TurboDieselRegister.com, a fleet business owner with DODGE one-tons and a variety of trailers):

"We tow several trailers and have run a 8 gauge wire from the battery to the trailer connector in place of the factory 12+ wire... we've also installed an 8 gauge ground... at the truck battery we have a 40 amp fuse.... from the male trailer plug we've used the same gauge wiring to power the battery and keep it charged...

On all our trailers we draw off the trailer batteries with a group of relays... using the 12+ as power to the relays and run clearance, turn, and backup lights from these relays... we have 50 watt bulbs for backups on the trailers...

We use the power from the truck through the trailer connector as the trigger for the relays....

Since I own several trucks and several trailers this was a task... but in the long run we've had fewer problems.

If you look at the actual diameter of the wire going to the factory connector I can't see how it can carry the kind of current they expect in a modern trailer... power to the battery, lights, etc...

We've had problems with trailer brake circuits in the past with some of the wiring going through the axle from one side to the other.... the wire can chafe on the inside of the axle and cause high current and blown fuses... so on all our trailers we have a trailer junction box, and wiring to the trailer axles that is outside the tube....

We also use non-insulated butt connectors and shrink tubing.... we buy from Del City - Wiring Products and Professional Electrical Supplies a clear heat shrink tube that has an adhesive on the inside like what is used on water wells... this is a waterproof connection....

We understand and use ohm's law and the use of a digital meter...

Your brake controller should be fine... its the connections that worry me...."


(I prefer ANCOR "Marine Grade" wiring products as the USCG bans soldering for vibration-prone terminations; therefore these spendy products last forever).

On my vehicles I start by modifying the electrical system:

BIG THREE UPGRADE
http://forum.sounddomain.com/ubbthre...page/1/fpart/1

(more) BIG THREE UPGRADE
The OFFICIAL "Big 3" Upgrade Thread - Massdriven Automotive Forums

-------------------------------------------------------------------------------

One may think I have devoted too much space to trailer brakes, but,

perfect trailer/TV brakes will stop the rig sooner
than the TV does when solo.


--------------------------------------------------------------------------------------

Brake Controller

The following is the only brake controller I would consider (short of a conversion to trailer disc brakes where an approved controller must be sourced). One would be unlikely to find any commercial haulers who would settle for less, and the market is full of lesser controllers; as with the hitch recommended above (and disc brakes) no one who uses them EVER goes back to lesser contraptions:


MAXBRAKE BRAKE CONTROLLER
MaxBrake™ - Hydraulic over Electric Variable Brake Controller

"MaxBrake, the best trailer brake controller,senses your trucks hydraulic brake pressure for fast powerful trailer brakes, MaxBrake!"

http://www.southwestwheel.com/store/...ake-controller


.


Last edited by slowmover; 04-11-2010 at 01:27 PM..
  Reply With Quote
The Following User Says Thank You to slowmover For This Useful Post:
BamZipPow (04-12-2010)
Alt Today
Popular topics

Other popular topics in this forum...

   
Reply  Post New Thread




Similar Threads
Thread Thread Starter Forum Replies Last Post
Project: Rebuilding an '01 Honda Insight as a nonhybrid Fabio Hybrids 158 01-12-2013 11:59 AM
HYPERMILING & TOWING: A Misconception slowmover Hypermiling / EcoDriver's Ed 27 12-14-2011 07:20 AM
I build a 4x4 Gas-Electric-Hydraulic Hybrid! bennelson Hybrids 5 02-10-2010 12:53 PM
Efficiency When Pulling A Trailer grease87 General Efficiency Discussion 30 07-26-2009 12:07 PM
'98 Dodge Caravan 3.0L - 26 mpg pulling a trailer & 24 mpg pulling another car :) MetroMPG General Efficiency Discussion 7 05-25-2009 12:27 PM



Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com