Gasser Handling - Specific Question

[FloridaRosebud]

I have a specific question regarding improving the handling on my 33' National SeaBreeze. I realize there have been many threads on this topic (I've participated in some of them) but I've not seen this discussed. The MH is 33', 208" wheelbase, F-53 chassis. I've done the CHF, have a steering stabilizer, and added a Hellwig rear anti-sway bar. Firestone airbags as well, and run the "correct" tire pressures based on the MH weight (actually weighed). All this improved the handling greatly, and pretty much eliminated the wandering.

So the question - is there any additional improvement to be had adding the Hellwig front anti-sway bar, or have I reached the point of diminishing returns? I would say at this point I've gone from many butt-puckering moments to maybe 2 or 3 over a 300 mile day, as most larger trucks no longer push me around like before. To put a number on it I'd say everything has improved 70-80%. As an aside, I've found that running the driver side air bags at 30psi, and the passenger side at 45-50psi also helped tame the "push" and improved stability.

Thoughts?

Al

[FloridaRosebud]

Cloud Dancer wrote:
The center of mass is located ABOVE the roll axis (on your motorhome). If a lateral force is applied above the roll axis, the suspension springs on one side will compress, and the body will tilt to the same side. You can call it whatever you want, but the motion is "tilt" or "roll". Therefore, what you call a "anti-sway bar" I call anti-roll bar.
The performance characteristics of a motor vehicle chassis have been assigned their respective name. Three of the more common are: understeer, neutrol steer, and oversteer. Another is "quality of directional stability". There are adjustments, and/or modifications for the purpose of changing the "handling" qualities of a chassis.
In auto-racing vernacular, sometimes understeer is described as "pushing" or "plowing". And, oversteer is described as "loose", or "wants to come around" or "wants to spin out".
Changing the diameter of the anti-roll bars has more to do with changing the understeer and oversteer, whereas changing the "wheel rates" (spring rates) has more to do with directional stability, or "quality of ride".

I understand your terms, as I used to race SCCA. I'm using the term "sway bar" as that's what the manufacturers call them, so to the "normal" person that's what they would understand. The addition of the bar to the rear made a huge difference in keeping the MH from rolling and from semi's pushing me over (along with the CHF and the correct tire pressures). If I didn't do anything else I could live with the MH as is, but I was wondering what, if any, improvement I might get from adding the front anti-roll bar. I can not seem to find any good information from users so far to my specific question, which, in truth could be the answer...;)

Al

[Cloud_Dancer]

What would I do? I did it already, many years ago.
On a friend's Winnebago Adventurer, I install a long piece of 3" exhaust tubing (properly attached) across and beneath the most-forward part of the front frame (filled with lead shot), PLUS some sandbags in the front. I actually added about 300+ lbs of ballast to the front. THEN, I increased the caster by about 3 degrees. (my brother ran a large fleet maintenance and repair shop on I-10, which I owned). I also made sure the toe-in adjustment was correct).

[Cloud_Dancer]

The center of mass is located ABOVE the roll axis (on your motorhome). If a lateral force is applied above the roll axis, the suspension springs on one side will compress, and the body will tilt to the same side. You can call it whatever you want, but the motion is "tilt" or "roll". Therefore, what you call a "anti-sway bar" I call anti-roll bar.
The performance characteristics of a motor vehicle chassis have been assigned their respective name. Three of the more common are: understeer, neutrol steer, and oversteer. Another is "quality of directional stability". There are adjustments, and/or modifications for the purpose of changing the "handling" qualities of a chassis.
In auto-racing vernacular, sometimes understeer is described as "pushing" or "plowing". And, oversteer is described as "loose", or "wants to come around" or "wants to spin out".
Changing the diameter of the anti-roll bars has more to do with changing the understeer and oversteer, whereas changing the "wheel rates" (spring rates) has more to do with directional stability, or "quality of ride".

[rgatijnet1]

Up you air bag pressure to 80 psi and take it for a drive on the highway. This costs nothing and it may be all that you need to do to minimize sway.

[stripit]

I also did the CHF to the front end, weighed the rig and adjusted the tire pressures. A bit better but not to my liking. Added a rear panhard bar and THAT made a huge difference in the way it felt when driving in winds or being passed by semi trucks. No more fighting the steering wheel trying to go straight down the road.

[Big_Katuna]

What handling characteristics are you hoping to improve?

My thinking is that more front sway is always better but you’re improving lean on curves.
Not stability from crosswinds or trucks passing.

The rear panhard rod (Davis Tru Trac being a brand) will make a huge improvement in stopping the tail wagging the dog when wind pushes the rear over hang.

Something we did back in my early years amateur auto cross racing with low budget is take another stock sway bar and simply clamp it to the existing sway bar. It worked.

[FloridaRosebud]

OK, while I appreciate everyone's responses, I guess I'm just not being clear here. I've already listed what I've done (and am not going to change what's been done), and I'm just asking if a larger front anti-sway bar would be worth doing. I'm not asking what to do to help my handling (although the air tabs look interesting), there has just never been discussion that I've seen that would or would not justify spending the money on a larger front anti-sway bar. Stock front bar is 1" with rubber bushings. The Hellwig is 1.75" with poly bushings. So has anyone actually changed out their front anti-sway bar and seen an appreciable improvement?

FYI - Shocks and rear sway bar are new and our rear storage (good point @All I could afford) is minimal.

Al

[phnguyk]

Air Tabs, LOL.
Rear track bar is what you want to look into.

[All_I_could_aff]

Something that seemed to help on my bosses 36 foot F53 Fleetwood Discovery was minimizing the amount of weight stored behind the rear axle. We never scaled it before and after to be sure, but There were times when the rear most storage compartments on the outside were absolutely stuffed full of cases of water bottles and beer. On subsequent trips we moved them more toward the midpoint of the wheel base, and used the rear storage compartments for bulky light items like fishing poles, sleeping bags, bundles of paper towels, etc.

[STBRetired]

Track bar, new shocks (Bilstein or Koni)

[Big_Katuna]

Add a Davis Tru Trac.

[Dale_Traveling]

Why no rear track or pan head bar?

[rgatijnet1]

Some people, including myself, have had good results from using AirTabs to help stabilize the coach and minimize and push from trucks. There are several users who may post their actual experiences on here with AirTabs as well as several non-users who will post their opinions. For me, the cost for the AirTabs was about the cost of a tank of fuel.
I did also have air bags and on windy days or smooth highways, I ran the pressure up to around 80 psi.
I never saw any need to add a track bar or additional anti-sway bars on my Workhorse chassis.