Which suspension mod is better Air bags or the Roadmaster active suspension? And why did you choose what you did.

 

RAS. I needed an extra inch in the rear after my lift and my trailer isn't very heavy. For me, a perfect match.

 

I installed the Firestone Ride Rite Air bags 4 years ago and have towed my 11K hauler for 30K miles since then. Why do you need RAS, couldn't tell ya why! Air Bags leveled my truck and stiffened the rear end which cured ALL of my wandering issues. The top reason why I chose air bags is because I have tons of flexibility! I can run 5psi or 100psi depending on my load! It's easy to adjust, oh yeah I just fill them up with air or let the air out. At 80psi the rear of the Excursion is rock solid and then when I disconnect the trailer it's back to stock at 5psi! You can add 2" inches of lift with the bags maxed out, I've measured it. I considered RAS but am so glad I opted for the more flexible Air Bags so I can set them how I like and can raise or lower the rear end as needed. Most of the guys I talk to here in AZ all go with the bags because of these same reasons! I'm happy with them can't you tell?

The other thing I did that was very noticeable was install the Rancho 9000xl shocks. They also are adjustable which is great and changing the shock settings really does make a noticeable difference!

 

I went with RAS on the X. I had airbags on my Nissan TItan but I did not have an on-board compressor so I had to dig out the compressor anytime I wanted to add air. I like that the RAS is always "active" when you need it and that it added about 1.5 inches of lift to the rear. I had no complaints with my air bags but the ease of use and the initial cost caused me to try out the RAS this time and I have no complaints.

 

Hard to say. I had air bags on my 2003 and now have RAS on my V/B spring code 2005.

In my mind, you "add on" to rear suspension for one of at least two reasons:

1) To minimize "sag" when you hitch up to a heavier trailer.
2) To minimize "wander" in the steering all the time, but especially when towing or hauling a heavy load.

The air bags:

Pro- a) do a great job in handling extra load on the rear end.
b) extremely adjustable and flexible.
c) help to level the load.

Con- a) a bit complex. You have to add air either with a compressor or by using air source. If you don't have a compressor on board, you have to stop all leaks.
b) They don't do much to assist with "anti-roll"--you really need a Hellwig "anti-roll" bar to help with this.
c) And...they do very little to assist with "steering wander".
d) More expensive and time-consuming to install.

For the RAS:

Pro - a) raise the rear end by about 1".
b) Do handle some additional load.
c) Do assist some with "anti-roll".
d) Totally passive addition. You don't need to do anything to adjust for various loads.

Con - a) Don't really help much with heavy hitch loads, at least not as much as air bags.
b) Limited range of extra load carrying ability. Not nearly as much as air bags (in terms of range).
c) Not adjustable.
d) Will lift the rear end too much if you but on 3.5" tapered block with "B" code springs. I had to revert to stock 2" straight block and RAS to keep the "rake" of the 05 about right.

Now that I have done both systems, I probably would recommend RAS for most folks. It is just a lot simpler and helps the handling of Excursions in 95% of the cases applied. A great $200 investment, especially if you keep the stock "B/G" spring code setup.

For me, I am going to go back to air bags along with radius rods. The radius rods will be used to better control rear axle "wrap" (much better than any other technique). The air bags will give me more flexibility between soft unloaded ride and heavy hitch weights. I am especially wanting to level the rear a bit more than the RAS can do.

 

There is so much info out there about this subject I am confused. My loaded trailer is 8-9,000 pounds and sways around transfer trucks. I really don't want to invest thousands on an anti sway system. My idea is to install a sway bay (Hellwig or F350's) but from there I am confused between a RAS or bags? Fortunately I have a 2WD so I don't have the front sway issues.

 

Well, again, it all depends. From your photo, you have a pretty big sail area. I have to assume that you already have WD (Weight Distribution) hitch.

The sway you are getting is not started by a soft rear suspension. But, the soft suspension compounds the problem because the rear suspension of the TV (Tow Vehicle) then 'rolls'. The 'rolling' rear axle suspension actually enters into steering of the vehicle. The root cause of the problem is that the pivot point (of your trailer relative to TV) is behind the rear axle about 4 feet.

When a big truck passes you on the left, there is a higher velocity between the rear of your trailer and the leading "bow wave" of the truck. This reduces the net static pressure acting on your trailer in that area and 'pulls' the trailer toward the truck. The trailer pushes to the right at the ball, and this in turn pushes the front of the TV to the left--sort of a 'controls reversal'. When the bow wave reaches the front of your trailer, the opposite occurs and then the TV is pushed to the right. It is very unnerving.

Most "anti-sway" hitches attempt to prevent the pivoting motion between the Trailer and the TV. Most use friction, and some use opposing force (e.g. "Dual Cam"). At a minimum, a good WD hitch at least transfers enough weight to the TV front axle to allow you controllability in this situation. Stiffening up the rear suspension can also assist.

Both the Hensley and the ProPride use a mechanism (called a 4-bar linkage) in the hitch head to translate the pivot point forward to approximately the rear axle position, which negates the 'reverse controls' effect of a rear-biased pivot point. That is how both of these hitches prevent sway. It is also what makes them expensive. The pivot-point translation actually is only effective over small pivot angles. When you go around a corner, the pivot point moves back toward the trailer by way of the mechanism geometry. Effectively, the linkage "knuckles over", and then behaves much like a conventional ball.

Another hitch that does the same function is the Pull-Rite hitch, which keeps the pivot point always translated forward. The Pull-Rite is an arc-section of a circle, a curved beam mounted under the TV, along which the hitch pivots in a rolling carrier.

Knowing you don't want to spend the money for a Hensley or ProPride, it makes sense to try stiffening the rear suspension in 'roll' first.

For the money, the best to try first is Hellwig/F350 anti-sway bar (about $275). Then, the RAS (about $200) can be added to further stiffen the rear suspension in 'roll'. Air bags may work very well, but in my opinion do not directly resist "roll" of the rear suspension--there is no connection between the 2 sides of the rear axle like with an anti-roll bar. Plus, air bags are more complicated and more difficult to install. Both the Hellwig and the RAS are passive.

Another "cheap trick" to try involves weight distribution. Make sure you forward-load the trailer to about 15% (no more) on the ball. If at all possible, pack heavy items forward of but very close to the trailer axles. This minimizes any "pendulum effect" once the trailer starts to sway.

Keep the trailer and truck tires (Load Range E, right?) inflated to their maximum. Level the trailer so that both axles carry the same load. Keep loads in the trailer (and TV) as low as possible.

Finally, there is the hitch. You may get quite a boost in performance by spending on a "Dual Cam" or other "opposing force" type hitch. These are not much more $ than a conventional WD hitch and will help to lock the trailer and truck together.

 

Chinook907 - You don't say what you may be towing and/or any of the other mods that you may have done. I've gone thu my EX in the past 6 months to get it set up and so far I'm happy with the approach I've taken. Here is the order in whcih I did the "handling/Suspension improvements":

Reese Dual Cam hitch (properly adjusted via the Weight Station )
Swapped the front springs for V codes.
Rancho Front Shocks
Hellwig Rear Bar

Of the changes, I think the Hitch and the Hellwig did the most (Bang for the buck). I too would like just a bit more lift in the rear (since I have not yet changed out the G codes for modded B's the EX sits almost level hooked up the the TT. I think the next step for me (if and when some $ make them selves avaialbe) is Rancho 9000XL for the rear and RAS.

Good Luck!! (Former long time Alaskan myself) D

 

TXSailor, I have a 25' Toyhauler that is 29' tongue to tail. It has a dry weight of 5500lbs and I am usually towing it loaded up at about 8200lbs. I use a weight distributing hitch adjusted by the book(measurements of the back and front bumper) My main means of use for my EX is hauling. I bought my EX used and it has a 4" lift with 285's BF Goodrich KO's which are part of my problem, because hey are only load range D. I couldnt believe that someone would have put D's instead of E's, especially on a vehicle that heavy. I have Rancho 9000XL's all the way around which are due a replacement. Probably get the same or Bilstein's.

I would like to thank everyone's input, I appreciate it!

 

Thank you for he detailed response, you really clarified why my trailer sways so much.

The first thing I will do is a sway bar and possibly a RAS. I think that will help the truck in normal driving and when loadd get the nose down.

I do not have a WD system yet, the one I have will not work on a V-Nose. I do have E rated tires, I need to pump them to 70 when pulling, they were at 65 on my last long trip with it.

I know many people have dumped tons of cash into their Ex to get it to pull properly, I know it will be trial and error, hopefully I will get the right combination.

 

I have to agree w Scottman. I too have the Firestone airbags. I haul a 18' dove trailer w my 72 bronco on it. Let the air out of the airbags, hitch up the trailer, load the bronco. I have the switch installed in the console.....fill the bags to about 90psi and away we go. No sway or anything. Get to where I'm going unload and go back down to about 5-10 psi. Done deal.