Thor Vegas 2015 Steering Damper Issue

[JamieGeek]

Originally Posted by Cosmo

Someday I want to run an aero flow code on a model of my RV and see whats happening. Seems like some small fairings in the back might help with mileage and stability.
Here's an interesting study NASA did years ago:

There has been some discussion about that in this thread: Airtabs

Originally Posted by TyCreek

Steer by wire provides complete isolation and is likely not far off. Drive By Wire technologies has already replaced other mechanical linkages in vehicles today.

Given how long we had our last RV our next one will drive itself to our destination

[davidgebo]

I have discussed this mod a few times in this forum. I saw and felt the factory steering damper that came with the E-350 chassis under my Vegas. It is pretty much useless as far as steering control in a blowout situation. Just look at the video of the 40 foot diesel pusher rolling off the highway during a tire blowout to convince yourself of the value of an aftermarket heavy duty steering stabilizer. The factory damper unit is for steering comfort, I assume, and not intended to help with steering control in an emergency situation. Just look at the size differential between the factory damper and the Safe-T-Plus unit. The Safe-T-Plus is spring loaded internally on both sides for self-centering, and steering control. Their you-tube website shows the internals of the unit. Some aftermarket steering dampers have external springs, but I feel the Safe-T-Plus is far superior in design and engineering. They make several different sizes for varying coach chassis weights and lengths. It also has a lifetime warranty, which attests to the manufacturers confidence in their product. Having seen accidents and damage to RVs from blowout and out of control conditions, I am more confident driving my Vegas at high speeds knowing I have this added margin of safety for a relatively small price. The E-350 chassis is intended for many applications, motorhomes, delivery trucks, ambulances, U-Haul rental trucks, you name it. Therefore, it is a generic chassis that has just rudimentary chassis features to accommodate the array of differing uses after manufacture. Therefore, when we buy this chassis for motorhome use, we must modify it to our safety and use requirements. Finally, Safety-T-Plus will install the unit on your vehicle for free if you arrive at the factory.

[Oneilkeys]

Originally Posted by Cosmo

Someday I want to run an aero flow code on a model of my RV and see whats happening. Seems like some small fairings in the back might help with mileage and stability.
Here's an interesting study NASA did years ago:
http://ntrs.nasa.gov/archive/nasa/ca...9990047711.pdf

Interesting study... Their conclusion that the design of the after body (rear of the vehicle) (as well as underbody design) is just as important is reflected by many of the large trucks I see in Europe with the boat tail extensions. Fuel is so much more expensive in Europe that is makes real economic sense to make the vehicles as aerodynamic as possible. I've seen a few boat tails in the US, but many more in Europe.
So... are you going to design a boat tail for the Axis? Maybe some raised wing tips as well.

[DocMike]

Oneil,

So boat tail extensions is the name for all those wired in parts that look like the rear of the 52 ft Tractor/Trailer is not closed all the way. I'll guess that the curved vertical panel/structures under the Big Rigs also aids in aerodynamics of the rig.

Educational week for me, learned that the hand sanitizer I use at the office can cause my Stainless Steel sinks to rust due to Triclosan and now Big Rig aerodynamics.

Doc

[JamieGeek]

Someone posted a link to this guys efforts in the past; here just take a look at this boat-tail on an RV:

http://ecomodder.com/forum/showthrea...d-e-18151.html

[DocMike]

Jamie,

Wow. Thanks for Posting.

Doc

[Cosmo]

So... are you going to design a boat tail for the Axis? Maybe some raised wing tips as well.

Thinking about adding something small if numbers come out good. Getting a 1 mpg improvement is worth around $2K (assume 100K miles) in gas money. My problem is time - we are selling the house and spending a year on the road in Aug and its pretty low priority. I used to work at NASA and have lots of friends who could give me a hand with the aerodynamics if I find the time.

[davidgebo]

As I mentioned, there are several aftermarket steering stabilizers out there for RV owners to purchase. Blue Ox makes a system that is hydraulically controlled from a separate hydraulic pump and computer controls, and is quite expensive to buy and install. Mostly, the internal fluid and pre-loaded spring piston types, such as Safe-T-Plus seem to be the simplest, easiest to install and maintain, and the most reliable. As I have mentioned, seeing a 40 foot diesel pusher towing a full-size pickup truck go off the road and flip over on a median, was enough for me to decide to install a steering damper. The size and weight of a coach will not determine the stability and handling safety of a coach. It is simply a matter of physics. Sudden loss of a front tire at 75mph, will result in total loss of control, unless you are very lucky. A driver needs all the help he can get in this situation. A tire blowout is usually sudden, unexpected, and will take you by surprise. Tire pressure monitors can alert you to a high-temp tire, a slow-leak, or catastrophic tire failure, and can take the shock and surprise out of a blowout.
Several hundred dollars in equipment, properly installed and maintained, can be the difference between a happy vacation or a tragic, expensive nightmare. I made my choice, and I am satisfied that I did all I can to keep my family as safe as possible on the road.,

[davidgebo]

As I mentioned, there are several aftermarket steering stabilizers out there for RV owners to purchase. Blue Ox makes a system that is hydraulically controlled from a separate hydraulic pump and computer controls, and is quite expensive to buy and install. Mostly, the internal fluid and pre-loaded spring piston types, such as Safe-T-Plus seem to be the simplest, easiest to install and maintain, and the most reliable. As I have mentioned, seeing a 40 foot diesel pusher towing a full-size pickup truck go off the road and flip over on a median, was enough for me to decide to install a steering damper. The size and weight of a coach will not determine the stability and handling safety of a coach. It is simply a matter of physics. Sudden loss of a front tire at 75mph, will result in total loss of control, unless you are very lucky. A driver needs all the help he can get in this situation. A tire blowout is usually sudden, unexpected, and will take you by surprise. Tire pressure monitors can alert you to a high-temp tire, a slow-leak, or catastrophic tire failure, and can take the shock and surprise out of a blowout.
Several hundred dollars in equipment, properly installed and maintained, can be the difference between a happy vacation or a tragic, expensive nightmare. I made my choice, and I am satisfied that I did all I can to keep my family as safe as possible on the road.,

[Oneilkeys]

Originally Posted by JamieGeek

Someone posted a link to this guys efforts in the past; here just take a look at this boat-tail on an RV:

Aero RV (custom boat tail for '95 Ford E-350 Class C motorhome) - Fuel Economy, Hypermiling, EcoModding News and Forum - EcoModder.com

That is impressive! While I am not sure I want to add that much length to my 25' Axis, you would think that some RV manufacturer would take some of the easier mods and improve the gas mileage of their coaches by 10-15%. Using a lower A/C cover, closing off the under carriage and a little redesign of the rear might make a significant difference. When the price of gas goes up again, better gas mileage might just keep you in business. During the last $4 a gallon gas period, large RV sales plummeted with people looking for smaller rigs for better gas mileage. That could easily happen again.

[Oneilkeys]

Originally Posted by DocMike

Oneil,

So boat tail extensions is the name for all those wired in parts that look like the rear of the 52 ft Tractor/Trailer is not closed all the way. I'll guess that the curved vertical panel/structures under the Big Rigs also aids in aerodynamics of the rig.

Educational week for me, learned that the hand sanitizer I use at the office can cause my Stainless Steel sinks to rust due to Triclosan and now Big Rig aerodynamics.

Doc

Amazing what you can learn on this forum.

[Chance]

Originally Posted by TyCreek

Semantics ... Dampener ... Stabilizer ... a shock-absorber for steering... it's all the same.

There are a few slight design differences and Safe-T-Plus is one of the RTC options (Return To Center). RTC is simply biasing a center position via spring or gas. The one problem with a fixed center bias is that road crown/slope and wind, changes true vehicle center steering position. Some RTC systems offer in cab push button centering to address the changing conditions.

With marketing and semantics aside, they all otherwise simply provide resistance to movement e.g. absorb shock, stabilize, dampen.

Steer by wire provides complete isolation and is likely not far off. Drive By Wire technologies has already replaced other mechanical linkages in vehicles today.

If they have different functions and work differently, and affect vehicle dynamics differently, then to me they are not all the same.

[ptnormd1]

Thanks for all the follow up posts, Appreciate the Air Flow comments as it took me back to my old aero classes in college.

Got the Coach back today and it is much more stable on the rode and the steering feels tighter and has lost the looseness it had at the center.

Unfortunately I have another problem that requires a new thread.

[Mr Sunshine]

RE: Safety steer. Opinion alert! The following is my personal opinion, based on my personal experiences.

I had a front left tire blow on an interstate, at 65 mph, on my 33' Class A. No steering stabilizer on that F-53 chassis. The tire failure wasn't caused by low pressure, just age. While unnerving, it wasn't anywhere near the grave situation some have predicted. I let the coach slow on it's own, no brake, and pulled it over to the side after we cleared the overpass we were crossing.

I asked the professional truck center that did my alignment about a steering stabilizer for my 2015 Vegas, and they would gladly sell one and install it for me, they didn't recommend it. It's a personal choice and you do what you want. Based on what happened to me, I won't be installing a steering stabilizer on my Vegas.

[axis earl]

Could possibly be that the hardware on the F53 is different than the Econoline chassis. I had one installed on my E450 chassis with my Axis and I like the way it drives much better than before when it wasn't there. Long as the driver is happy with the way it drives, that is the real issue.

[rangemaster728]

This is a continual subject of discussion amongst motorhome owners...

In my case, I bought a (new) 2016 Thor 22FE class C on an E450 chassis. I thought it handled OK, but I've driven alot of things...my wife was terrified to drive it (it's NOT a Honda Crosstour LOL).

The first thing I looked at was weight distribution...Ford spec says 35-40% weigh goes on the front axle...check.

Next was tire pressure...the flying monkeys at Camping World had all 6 tires set at 80 psi...wrong. A 4-corner weighing and a call to the guys at Michelin (they made the tires) yielded target pressures at 65 front, 75 rear. Handled better.

Then I looked at alignment...everything was within spec EXCEPT camber, which was way off. A good alignment (and $160 later) it improved even more...BTW, Thor reimbursed me for the alignment.

Lastly I ditched the flimsy steering stabilizer and installed a Safe-T-Plus myself, did the calibration and it improved the handling ever more...I swear I've seen bigger gas struts on a screen door closer than the stock Ford one. It's a steering stabilizer and a return-to-center device. Ran me about $380 with the bracket kit, an hour to bolt it on and about another hour to dial it in.

No...an E450(or E350) chassis will not track and feel like a quality sedan...ever. But it's much better now and the wife will drive it.

[TyCreek]

Think about what a steering stabilizer is and how it works It simply connects to the frame and the steering arm. As such it only controls/dampens movements of that arm. From a tuned chassis perspective that arm should have minimal movement other than positioning wheel direction.

Again, a steering stabilizer does not FIX a chassis steering issue. With a well tuned (not just in spec) steering/suspension system and good roads you should feel little differences with or without a stabilizer installed. A good reason to remove the stabilizer when test driving a rig.

As shock valving increasingly resists movement it will likewise increasingly dampen and "mask" less than optimally tuned steering behaviors. Certainly at a point of optimal tune the a dampening increase becomes icing on the cake so to speak because it adds driving comfort due to feedback isolation. This added comfort is too often expressed as a FIX for chassis handling/steering issues.

The amount of safety in a blowout condition is not a factor of size or what you might feel by hand actuating a unit but rather the valving characteristics designed into a given unit. A typical stock shock can provide excellent fast movement isolation and also be easy to move by hand.

A lightly dampened shock will provide the most feedback into the steering wheel. Drivers often react to this feedback with impulse corrections that cause yet more feedback to create a poor handling feel. How much bump steer is driver vs. chassis? Solving a drivers reaction tendencies with increased dampening is priceless but it fixes the driver not the chassis.