Is a WDH needed?

[brods]

Just throwing this out there.

Darling, J., Tilley, D. and Gao, B. (2009) An experimental investigation of car-trailer high-speed stability http://opus.bath.ac.uk/14234/

3.5 Devices to enhance trailer stability

3.5.1 Trailer stabilizer

To improve the trailer stability, various stabilizer devices are commercially available. Among them, friction stabilizers are the most common. Figure 14 shows the effect of a stabilizer for a less stable trailer setting. It was found that, although the stabilizer is beneficial and increases the damping ratio, the improvement is limited. In this instance, the zero damping speed increased from 61 mile/h to 66 mile/h. This suggests that a driver should still drive cautiously at a sensible speed even if a stabilizer is fitted. The findings here are supported by the simulation study conducted by Sharp and Fernandez [7], which concluded that a friction stabilizer can only provide limited benefits to trailer stability.

4 CONCLUSIONS

Very little work has been published on the experimental measurement of high-speed car–trailer stability. In this study, extensive experimental measurements were carried out on a combined car–adjustable trailer system. By adjusting the trailer settings, the effect of different trailer parameters on the system stability was examined. It was found that the dominant factors affecting stability were the trailer yaw inertia, nose mass (load distribution), and trailer axle position. The tyre pressure also affects the stability, although the effect is less significant. It is interesting to see that the trailer mass alone does not dramatically affect the stability; however, as a heavier trailer normally has a larger yaw inertia, a limit should be placed on the relative car–trailer masses.
A friction stabilizer is shown to be helpful in improving the system stability, although in these tests the stability was not increased hugely. In addition, high-speed towing tests were carried out on cars fitted with an ESP which automatically brake individual wheels and control the engine throttle position should the vehicle dynamic response differ from that expected. These tests demonstrated that, if the dynamic response ‘error’ exceeded a preset threshold level, the ESP operated and the highspeed stability was improved by controlling the car yaw oscillation associated with trailer instability.

 

[kthaxton]

Fortunately, I didn't waste any of my money....I bought a WD hitch for its weight distributing capabilities, any sway minimization features (real or perceived) were included at no extra cost.

 

[GAmes]

Heck, even the ESC system in our trucks is designed to sense trailer sway and alternate braking from side to side to help control it. There must be some reality here.

The ESC can alternate braking from side to side of the truck, not the trailer. If it shoots some electricity to the trailer brakes I can see it being effective at canceling out the little side to side but it sure would cause a reduction in mileage and trailer brake shoe longevity if it applies the trailer brakes every time a truck passes or the wind gusts from the side. A steady crosswind would cause havoc.

Fortunately, I didn't waste any of my money....I bought a WD hitch for its weight distributing capabilities, any sway minimization features (real or perceived) were included at no extra cost.

One more entry on this and I'm finished. I paid $50 for my WDH. A brand new one is about $200. Anything more than that is an extra cost.

 

[kthaxton]

The ESC can alternate braking from side to side of the truck, not the trailer. If it shoots some electricity to the trailer brakes I can see it being effective at canceling out the little side to side but it sure would cause a reduction in mileage and trailer brake shoe longevity if it applies the trailer brakes every time a truck passes or the wind gusts from the side. A steady crosswind would cause havoc.

I'll be sure to let Ram know they did it wrong.

 

[GAmes]

I'll be sure to let Ram know they did it wrong.

No, you got it wrong. The ESC doesn't apply braking to the trailer. The "trailer sway control" aspect is nothing more than more gimmick, more marketing. A trailer that is really swaying would need to have it's brakes activated.

 

[kthaxton]

No, you got it wrong. The ESC doesn't apply braking to the trailer. The "trailer sway control" aspect is nothing more than more gimmick, more marketing. A trailer that is really swaying would need to have it's brakes activated.

No actually I didn't get it wrong. Ram is the one who makes the truck and Ram is the one who makes the claim that their ESC can potentially minimize the affects of sway by alternately applying brakes on the truck when sway is detected.

 

[AH64ID]

It is my understanding that the trucks rear axle service brakes are applied if sway is detected. It was a marketing gimmick that, IIRC, Ford first used on the F-150. Due to marketing it is used on other trucks.

It sure isn't anything I want on my truck!

If I don't recall correctly and the trailer brakes are applied I really don't like it.