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 > New suspension upgrades

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ron.dittmer

North-East Illinois

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Posted: 01/05/22 06:55pm Link  |  Quote  |  Print  |  Notify Moderator

bobndot wrote:

EMD360, if the 22' rv was on a 350 and the 26' is a 450, then that might be why you feel the difference in ride. Maybe ?

Regarding potholes,
you're driving a truck with suspension to haul a home. It's going to feel a bit rough at times. It has to be stout enough to haul its weight. These mods that we are doing, all may help a bit but at the end of the day...it's still a truck !

My mods included the larger sways, Koni's in the rear, Bils front, steering stabilizer , rear track bar , a good reputable positive caster alignment and I run my psi in my 24 ft class c, a little softer because I'm underweight by 2000 lbs,.
I run 75 lbs Rear and 70F.

IMO, the rear track bar, which I did at the same time as the shocks, gave the most bang for the buck. That combined with the lower front psi to 70 seems like its offering more footprint on the pavement, resisting be pushed by passing bow-waves.
Bob,

Great input!

Our rig on an E350 chassis is a tad shorter than yours. I weighed our rig during a few different trips to learn that the weight is very consistent. I replaced the tires this year and followed the manufacture recommended tire pressure per the actual weight. To my surprise, I learned that my front tires should be only 40psi and my rears at 63psi. I run the rears per spec at 63 but up front at 50psi because I was chicken to lower it more. Next year I will run a little less in the front tires.

When fine tuning psi, you surely need a trusted tire gauge.

* This post was edited 01/06/22 02:54am by ron.dittmer *


2007 Phoenix Cruiser model 2350, with 2006 Jeep Liberty in-tow

bobndot

USA

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Posted: 01/05/22 08:03pm Link  |  Quote  |  Print  |  Notify Moderator

Hi Ron,
I ran my front ‘E’ plys at 45-50 psi on my former truck campers for years. I’m also starting to experiment with lowering psi more on my ‘C’. The ride does feel like it bites more when steering, which feels good to me. I’m assuming it has a positive affect with passing big rigs. It feels like it does. Driving behind big rigs with their turbulence can be challenging too. I often back off my throttle to afford me more distance.

Happy New Year ,
Bob

melandme

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Posted: 01/05/22 08:25pm Link  |  Quote  |  Print  |  Notify Moderator

I have done both the Hellwig sway bars and the Sumo springs on a 2016 25B. Put both front and rear sway bars on at 5K miles. Really made difference when being passed by big trucks. I describe it as going from a shove to gentle push. Installed Sumo springs this summer at 38K miles before a trip to Vermont. With the Sumos when a truck passes there is still a push but more like a nudge. Where I notice the Sumos most is there is less side to side rocking when turning in and out of parking lots and other places at slow speeds. The wife says the ride is better when sitting back in the coach. When at the camp site you do not get as much bounce when moving in the coach. As for smoother ride over rough road, after driving thru WV and MD interstate construction, they didnt seem to help much.

melandme

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Posted: 01/05/22 08:41pm Link  |  Quote  |  Print  |  Notify Moderator

Forgot about tire pressure. Running 65 front and 70 rear. Starting out at 70 and 80 which was way to much. Best thing is to weigh the rig and look up pressure for your weight. Then adjust pressure to where it feels right. I believe for my weight the PSI was a couple pounds lower. The extra couple pounds still drives wells and gives a little weight cushion.

EMD360

Arvada, CO

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Posted: 01/06/22 12:34am Link  |  Quote  |  Print  |  Notify Moderator

Thanks for the input. I only got the front sway bar. My shop said they don’t install rears. I especially wonder about the addition of the Sumo springs. Our mechanic works on motor homes but only in good weather because their garage is not large enough.
I’ve not yet weighed the rig. Thought I’d be fine at recommended pressure for now. Should do that as soon as the weather clears. We have a cat scale not too far away.
I downloaded a weight chart for Michelin’s. Here are the weight limits for our e350. So it looks like lower pressure in back. 65 in front and maybe 55 in back. Seems really low if door label recommends 68.

GVWR (Lbs): 11500
GCWR — 18,500
GAWR front—4600-2300
GAWR back—7200-3600

LBS
SINGLE
60-2190
65-2335
70-2440
75-2560
80-2680
DUAL
50-3530
55-3750
60-3990
65-4300
70-4440
75-4660
80-4940


2018 Minnie Winnie 25b New to us 3/2021
Former Rental Owners Club #137
2003 Itasca Spirit 22e 2009-2021


ron.dittmer

North-East Illinois

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Posted: 01/06/22 02:52am Link  |  Quote  |  Print  |  Notify Moderator

As I mentioned earlier, I bought new tires. This is the chart for these specific tires.
[image]

ron.dittmer

North-East Illinois

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Posted: 01/06/22 02:57am Link  |  Quote  |  Print  |  Notify Moderator

bobndot wrote:

Hi Ron,
I ran my front ‘E’ plys at 45-50 psi on my former truck campers for years. I’m also starting to experiment with lowering psi more on my ‘C’. The ride does feel like it bites more when steering, which feels good to me. I’m assuming it has a positive affect with passing big rigs. It feels like it does. Driving behind big rigs with their turbulence can be challenging too. I often back off my throttle to afford me more distance.

Happy New Year ,
Bob
Our assessments agree 100%. I am a little concerned of soft sidewall motion from lowering the front tire psi so much, but so far so good. That is why I am lowering the psi incrementally. I am considering 45 psi in the front tires during our next trip and see how that feels.

And a Happy New Year to you and everyone else reading this.

* This post was edited 01/06/22 03:04am by ron.dittmer *

ron.dittmer

North-East Illinois

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Posted: 01/06/22 03:16am Link  |  Quote  |  Print  |  Notify Moderator

melandme wrote:

I have done both the Hellwig sway bars and the Sumo springs on a 2016 25B. Put both front and rear sway bars on at 5K miles. Really made difference when being passed by big trucks. I describe it as going from a shove to gentle push. Installed Sumo springs this summer at 38K miles before a trip to Vermont. With the Sumos when a truck passes there is still a push but more like a nudge. Where I notice the Sumos most is there is less side to side rocking when turning in and out of parking lots and other places at slow speeds. The wife says the ride is better when sitting back in the coach. When at the camp site you do not get as much bounce when moving in the coach. As for smoother ride over rough road, after driving thru WV and MD interstate construction, they didn't seem to help much.
I have no first-hand experience with Sumo springs, but I wonder if our heavy duty Bilstein-RV shocks achieve similar results under the conditions you mention.

When it comes to softening the ride, lowering your tire psi to the actual weight being carried, is most effective.

During your weigh-ins, if you learn that your front suspension consistently has a lot of excess load margin, then you might want to consider what I did HERE which helped soften the ride for us and the house up front quite nicely. Our 2007 E350 front suspension originally was rated for 4600 pounds, but our actual weigh-ins have been consistent at 3260 ponds. The 1340 pound difference sounds negligible, but for ride comfort, it is a lot. I replaced the 4600 pound springs with 3750 pound progressive springs which yielded great results. We can still add an extra ~400 pounds on the front suspension before reaching the reduced limit, so if we have some extra passengers, we are still in good shape. But it's been just the two of us for nearly every trip. We've had an extra person with us a few times for short durations, but each person weighed less than 140 pounds. I assume half of that weight of 70 pounds was placed on the front suspension at that time.

* This post was last edited 01/06/22 02:21pm by ron.dittmer *   View edit history

ron.dittmer

North-East Illinois

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Posted: 01/06/22 03:43am Link  |  Quote  |  Print  |  Notify Moderator

EMD360 wrote:

I only got the front sway bar. My shop said they don’t install rears.
I find that strange. My brother and I installed a heavy duty rear Helwig stabilizer bar on his 1998 E350 motorhome. It was a lot harder than the front would be but only because we did not drive the rear tires on leveling blocks for improved working clearance.

A heavy duty rear stabilizer bar is most effective. I would suggest your shop drive the rear tires on your leveling blocks to help in getting it installed.

Grit dog

Black Diamond, WA

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Posted: 01/06/22 10:39am Link  |  Quote  |  Print  |  Notify Moderator

Sumo springs increase the spring rate. Are you in a too soft/feels “overloaded” condition?

It’s virtually impossible to accurately recommend modifications from a very basic description like “it rides rough.”
And it’s also highly subjective where one person may accept that they’re driving an overgrown 1ton van with 3 tons of house on the back and another is expecting a Cadillac ride.


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