Koni FSD Shocks

[LOG]

Would those members who have installed Koni FSD shocks on their Class C do it again? Or do you regret the decision. Thanks.

[klutchdust]

I did and would do it again. The banging and rough ride are non existent compared to the original shocks. I can't compare Bilsteins because I haven't had them on my coach.
I would not mix and match different brands to save a few dollars. Rv's cost money to operate and are a totally different breed of vehicle and require certain levels of care. Go cheap then do it over, me thinks.
Depending on if i am pulling a trailer or just hanging my Honda Ruckus off the hitch, I adjust the air pressure in the bags and that improves the ride also. I simply use a bubble level for a starting point then go from there.

[wearenh]

.


no experience with Bilsteins

I replaced the stock Ford shocks with Koni FSD and it made a world of favorable difference immediately

Now three years later, I still pat myself on the back for installing the FSD's

yes. I'd do it again, immediately

.

[hr_sea]

pnichols wrote:
As I've stated before in these forums - I have absolute proof that the Koni FSD shocks in the rear of our Class C reduced the cracks/pothole pounding back there when traveling: Both our shower door gravity latch back there now stays latched, and the little plastic shelf on the back wall never has it's contents bounce out.

Of course maybe Bilsteins would have done the same - but nothing in the Bilstein literature states that they provide a damping rate that varies depending upon the quickness (frequency) of road surface change.

I really think that where the high frequency light damping mode of the Koni FSD shocks comes into it's own is on RVs that are really stiff springed relative to the motorhome's weight (which is our situation with a 24 foot Class C on the E450 chassis). In these situations a quick bump in the road does not need any shock's resistance added to the spring's resistance - so light or no shock damping is better for reducing the jolt.

Most RVs on the E350/3500 chassis and larger RVs on the E450/4500 chassis - will have a higher vehicle weight to spring stiffness ratio that is not going to transmit sharp jolts from the roadway into the vehicle nearly as much as a lower ratio will. I'm sure Bilsteins (and many other shock brands) will handle these situations well enough.

Some of Bilstein's advertising actually states that. Unless you get into their really high performance stuff, they are digressive rate, which means higher piston speeds = less damping force. They'll feel firm on smooth road to tone down the wallow. They'll blow open on sharp bumps to soften the ride.

[pnichols]

LOG wrote:
Both rode like a new Lexus compared to this Class C motorhome.

Funny that you should mention that.

The daily driver sedan we own is a spectacular riding 2002 Lexus LS430 sedan. It was touted as one of the best riding sedans in the world (and barely affordable for us, even when bought used) ... of course not counting Bentley and Rolls-Royce, which are not affordable by mortals.

I sure wish I could afford to put full blown 4-Link Kelderman air suspension in the rear of our RV so as to have the ultimate - a small Class C on the overkill E450 chassis that rides like our LS430. The way I figure it cracks, ridges, potholes, etc. are only going to get worse on U.S. roads pretty much everywhere.

[LOG]

Pnichols,
Thanks for the explanation. I do believe that the shocks are not doing their job. And the rear may be hitting the stops. But the rough riding I am talking about is rough interstate and other roads that have ripples, ridges, cupping and other rough surfaces. I am going to install Koni FSD shocks on the rear. I will report back with the results. I have owned a 36 ft Foretravel Class A motorhome and a Winnebago 27 ft Class A motorhome. Both rode like a new Lexus compared to this Class C motorhome.

[pnichols]

LOG wrote:
Our coach weight on rear axle is 9360 pounds. The axle weight rating is 9450. According to this discussion, the coach should not be pounding as much as a lighter weighted E450. Our coach pounds a lot and is the reason I am thinking about new shocks. I have never ridden in another e450 motorhome, shorter or longer. I do not believe that the pounding could be more than the pounding in our motorhome.

I don't question that what you're experiencing is what you consider as a rough ride. 9360 pounds in the rear definitely makes it appear that your RV is a heavy/larger motorhome on an E450 chassis.

However, your pounding with that heavy of a coach-plus-E450 weight combination in the rear does not make normal sense - unless you're suspension is either hitting the stops because your rear springs are weak, or your rear shocks are no longer damping much or at all.

When my rear suspension components are OK and my rear shocks are OK... my 4X4 pickup truck rides better with weight in it's bed (terrible with nothing in the bed), my heavy daily driver sedan rides even better with a full gas tank, and my small Class C E450 motorhome with Koni FSD shocks in the rear rides even better with full grey, black, and gas tanks (all in the rear).

Heavy carrying weight relative to suspension weight ratings is supposed to make for a smoother ride over cracks/potholes if shocks are right. Lighter carrying weight relative to suspension weight rating is supposed to make for a rougher ride over cracks/potholes - made even worse by shocks with heavy damping on those cracks/potholes.

[OFDPOS]

pnichols wrote:
As I've stated before in these forums - I have absolute proof that the Koni FSD shocks in the rear of our Class C reduced the cracks/pothole pounding back there when traveling: Both our shower door gravity latch back there now stays latched, and the little plastic shelf on the back wall never has it's contents bounce out.

Of course maybe Bilsteins would have done the same - but nothing in the Bilstein literature states that they provide a damping rate that varies depending upon the quickness (frequency) of road surface change.

I really think that where the high frequency light damping mode of the Koni FSD shocks comes into it's own is on RVs that are really stiff springed relative to the motorhome's weight (which is our situation with a 24 foot Class C on the E450 chassis). In these situations a quick bump in the road does not need any shock's resistance added to the spring's resistance - so light or no shock damping is better for reducing the jolt.

Most RVs on the E350/3500 chassis and larger RVs on the E450/4500 chassis - will have a higher vehicle weight to spring stiffness ratio that is not going to transmit sharp jolts from the roadway into the vehicle nearly as much as a lower ratio will. I'm sure Bilsteins (and many other shock brands) will handle these situations well enough.

I'd bet had you replaced the old shocks with the Bilstein's you would of had the same results...

Even tho it doesn't state it in any of Bilstein's literature. 😉

[OFDPOS]

gmctoyman wrote:
Replaced relatively new yellow shocks with the FSD's, would not hesitate to do it again. Had them on my Foretravel and loved them there also.

Do tell on the "yellow" shocks most likely Monroe's ?

Never cared for them either 😉

[OFDPOS]

IAMICHABOD wrote:

OFDPOS wrote:
Nope would not do it again . Yes I regret putting them on.
Listened to the popcorn gallery instead of my gut feeling telling me to stay with the Bilstein's !

I have read all of your posts about the FSD shocks and I would not be interested in them at all,I will stick with my Bilsteins!

I was wondering if This offer is still open,who knows you may have a taker :B :B :B

LOL
They now have 4,000 miles on them but yes offer still there ..

[gmctoyman]

Replaced relatively new yellow shocks with the FSD's, would not hesitate to do it again. Had them on my Foretravel and loved them there also.

[LOG]

pianotuna wrote:
It is a delivery van. It rides rough. I'd love to know how to fix that.

That said, my previous RV was an E-350 and adding a leaf made the ride a lot smoother.

No disrespect intended, but it is a motorhome on a Ford E450 Cutaway chassis. It is not a van. The fact that added leaf springs helped the ride on your previous E350 indicates that there may be ways to improve the pounding and the ride.

[pianotuna]

It is a delivery van. It rides rough. I'd love to know how to fix that.

That said, my previous RV was an E-350 and adding a leaf made the ride a lot smoother.

[LOG]

Our coach weight on rear axle is 9360 pounds. The axle weight rating is 9450. According to this discussion, the coach should not be pounding as much as a lighter weighted E450. Our coach pounds a lot and is the reason I am thinking about new shocks. I have never ridden in another e450 motorhome, shorter or longer. I do not believe that the pounding could be more than the pounding in our motorhome.

[pnichols]

LOG wrote:
Are you saying that an 30 ft rv on a E450 chassis will have a different weight to spring ratio than an 25 ft rv on the E450 chassis? I thought that all E450 chassis in the 2005 year had a rear axle weight rating of 9450 pounds. Are you saying that some E450 chassis have different springs?

The "weight" I'm talking about is the weight of the coach. All E450 chassis of a given year-range have the same coach weight carrying capacity.

When a heavier coach is built onto a given E450 chassis, it's more difficult for the springs to raise the coach up when hitting a small roadway bump. Hence the springs just bend more themselves (than they would with a light weight coach) ... instead of the coach getting thrust upwards as much. This then makes the roadway bump feel less severe inside the coach.

The "ratio" I'm talking about is the weight of the coach versus the weight carrying capacity ("stiffness") of the springs carrying the coach.