Best single KDSS-compatible suspension option for slight lift, soft ride

[EddieV4runnin]

Too much speculation about the theory and operation of KDSS on this thread and just about everywhere it’s mentioned. Without any concrete information detailing its operation the “KDSS is too harsh” statement should be taken off the table.

 

[mrblah]

Too much speculation about the theory and operation of KDSS on this thread and just about everywhere it’s mentioned. Without any concrete information detailing its operation the “KDSS is too harsh” statement should be taken off the table.

You are aware that we are having a discussion on a forum where everything said is going to be considered ancedotal evidence. Nobody is going to dispute that, but that doesn't mean people can't have a discussion.

However, if you feel that other people's own experiences aren't concrete enough for you, feel free to move along.

 

[mrblah]

I can't remember if its the BP-51 or Icons, but I recall people mentioning specifically setting 4 (out of 20) being equivalent to stock, lower softer, higher firmer. While KDSS will always be firmer than non-KDSS when equiped/configured the same, wouldn't running on a lower setting offset the difference?

You will have to ask the shock guru's on this one. Basially, all shocks are designed within a certain range (rebound and compression) in mind, and within that range, they allow some degree of adjustability (such as the bp-51). Usually, you adjust the shocks to match the spring rate you choose, to give you the best ride/performance within that range. The adjustments aren't infinite.

The BP-51's can adjust both rebound and compression, whereas the kings can only adjust for compression. I suspect that the BP-51's can only adjust so much from baseline, that you won't see a huge difference.

In regards to my kings, which only adjust for compression, you would think I can adjust the firmness of my ride, but only after my suspension compresses. Basically, for me, I can adjust my ride from firm but bouncy over bumps to just straight up firm with no bounce after a bump. So basically the firmness is always there, its how the suspension reacts after I hit a bump that changes. Even then, its not mind-blowingly different.

Idealy, the adjustment is there if you already tuned your suspension (properly valved shocks w/ the correct spring rate that corresponds to the weight of your vehicle), and you want to make small, minute and incremental changes. For me, i have mine set at the softest setting or zero clicks because I want the softest setting over bumps, and because I don't have the correct springs mated to my shocks (I ended putting a lot of weight to my 4runner after I installed my suspension).

Most people don't have the time or money to tune the shocks to their specs, so they go with what others are running, or what the manufacture suggests. That is also why, people will recommend suspension mods as the last mod you do, because the demands of your vehicle (more likely the weight of your vehicle) will change over time

As for KDSS vs non-kdss go test drive both on a crappy road somewhere. There is a night and day difference in which vehicle will have a firmer ride.

 

[EddieV4runnin]

You are aware that we are having a discussion on a forum where everything said is going to be considered ancedotal evidence. Nobody is going to dispute that, but that doesn't mean people can't have a discussion.

However, if you feel that other people's own experiences aren't concrete enough for you, feel free to move along.

.........................:car:

 

[DeepSea]

Does anyone have any recommendations for the best spring/shock brand/part #s for the below?

-KDSS friendly
-1-3" lift max (my garage door is 6" above my roof at stock height now, and need to leave a little for bigger tires.
-As soft/buttery of a ride as possible.
-I don't pack the truck too heavily. Usually under 1,200 lbs combined people and cargo weight, so I don't need anything super firm.

Thanks!

Unless you're planning on off-road racing, you do not need a reservoir suspension from King, Fox, Icon, etc.. Yes those are the most badass/capable off-road suspension systems out there but they aren't cheap and definitely not needed for a daily driver/occasional off-roader. The consensus is King is KING for a reason if you decide to go all out.

I truly enjoy the incredibly smooth ride quality of my rather inexpensive Eibach/OME setup and have had Fox, Icon, Bilstein, etc.. in the past. But keep in mind the wheel/tire combo will also make a world of difference in ride quality (Example: light BFG KO2 vs heavy Nitto Trail Grappler). Chose the lightest and lowest load rating to pair with the suspension. Just my .02

:cheers:

 

[HVLSTON]

Unless you're planning on off-road racing, you do not need a reservoir suspension from King, Fox, Icon, etc.. Yes those are the most badass/capable off-road suspension systems out there but they aren't cheap and definitely not needed for a daily driver/occasional off-roader. The consensus is King is KING for a reason if you decide to go all out.

I truly enjoy the incredibly smooth ride quality of my rather inexpensive Eibach/OME setup and have had Fox, Icon, Bilstein, etc.. in the past. But keep in mind the wheel/tire combo will also make a world of difference in ride quality (Example: light BFG KO2 vs heavy Nitto Trail Grappler). Chose the lightest and lowest load rating to pair with the suspension. Just my .02

:cheers:

Agree with you 100% wheel/tire combo makes a HUGE difference. I have KDSS paired up with Kings and when I was still on stock wheel/tire combo it was a little firmer over stock. But after I got my ridge grapplers (285/70/17) the ride was much more firm. Don’t get me wrong, I love my setup but if you want smooth like stock this ain’t the route to go.

 

[Jetboy]

Indeed, though regardless of swaybar thickness, the KDSS system is still engaged. Drive down the same rutted road with and without KDSS engaged on the same vehicle. It's not a nuanced effect, it's night and day. Not disagreeing with you here. Simply emphasizing this system is not trivial.

KDSS is always engaged. It never disconnects. You can't disengage it. What it does is open hydraulic valves below 12mph that link the front and rear cylinders in a master/slave system. Below 12mph they are still fully connected, they just change functionality from rigid cylinders to linked front/rear with forced articulation. It never gets softer in the sense that it allows more bump compliance at one tire.

What KDSS has no effect on is when you hit a bump with both front or both rear tires. In that scenario there is no influence. Just like every other anti-sway bar. The real effect of an anti-sway bar is to transfer spring force from the unloaded size to the loaded side. The difficulty with KDSS is that you have much greater variation in effective spring rate when you hit a bump on one side as compared to hitting a bump with both front tires. So tuning a shock to optimally work for both a high spring rate and a low spring rate is practically impossible. The best you can do is get somewhere in the middle so it works well for both.

The problem lies primarily in the middle speed situations. Between about 20 and 40mph. At higher speeds the shocks are doing almost all of the work in terms of resisting bumps. At lower speeds KDSS becomes active and does a fantastic job of both body stabilizing and articulation. But in that middle range it makes for a harsh ride due to the big sway bars. I think a lighter weight set of sway bars or changing the leverage of the system could go a long way toward making the offroad users happy. The LC200 has a much better KDSS system for example. The front is a very easy fix in that regard. Just move the bushings on the control arms inward by 1 or 2 inches. It would significantly change the leverage of the system.

The rear is a lot harder to modify for long travel and/or different leverage. In the rear I think a custom sway bar is the only realistic solution. BUT - it would require moving the spare tire to somewhere else. In order to extend the rear sway bar lever arms you'll end up putting the bar back into the spare tire area. I've worked through the design quite a few different ways. There may be other solutions, but that's about as close as I can come up with.

 

[DesertFish]

The problem lies primarily in the middle speed situations. Between about 20 and 40mph. At higher speeds the shocks are doing almost all of the work in terms of resisting bumps. At lower speeds KDSS becomes active and does a fantastic job of both body stabilizing and articulation. But in that middle range it makes for a harsh ride due to the big sway bars. I think a lighter weight set of sway bars or changing the leverage of the system could go a long way toward making the offroad users happy. The LC200 has a much better KDSS system for example. The front is a very easy fix in that regard. Just move the bushings on the control arms inward by 1 or 2 inches. It would significantly change the leverage of the system.

The rear is a lot harder to modify for long travel and/or different leverage. In the rear I think a custom sway bar is the only realistic solution. BUT - it would require moving the spare tire to somewhere else. In order to extend the rear sway bar lever arms you'll end up putting the bar back into the spare tire area. I've worked through the design quite a few different ways. There may be other solutions, but that's about as close as I can come up with.

I'm glad you mentioned this. Nobody seems to complain of an overly firm ride in the LC/GX. I could be completely mistaken but in my experience, KDSS seems to handle small bumps without too much fuss/harshness, where it really becomes quite annoying is with dips... potholes, sunken manhole covers etc.

Something else I and possibly a few others in another post noticed:
http://www.toyota-4runner.org/5th-gen-t4rs/258740-steering-feel-slop-changes-every-drive.html

Sometimes KDSS seems to get stuck in open mode. Again I could be completely mistaken, but very rarely, maybe 5 times in total in ~2.5 years, I go to drive my 4R and it behaves completely different from usual. It feels so much better. It doesn't feel dangerous or as if sway bars completely disconnected or anything like that, just soaks up any type of road imperfection incredibly well, with the only downside being very slightly less steering precision.

There is definitely a solution out there to a supremely soft ride. Even with KDSS. I'd definitely be interested in seeing what smaller diameter sway bars would do, maybe the ones on the 4R are just overkill.

 

[1996_Valencia_Owen]

I also feel like KDSS has a better effect once the truck is heavily loaded. like 4+ passengers, and some cargo.

Then, the roll reduction really helps, especially on-road, in places like mountain roads or national parks, where you ahve lots of sweeping curves and bends at decent speeds.

Where KDSS gets a bit more firm is when my truck's in commuter mode, and isn't loaded down with much. Then, the size of those sway bars really is noticable. But then again, it handles like my Mazda 3 GT on the highway, so I can't complain lol.

 

[GChristo]

KDSS is always engaged. It never disconnects. You can't disengage it.

True that it never disconnects, but one can certainly make it switchable, though that's not for the faint of heart and no, one cannot disengage (control) it stock. 100% with you on the rest.

where it really becomes quite annoying is with dips... potholes, sunken manhole covers etc.

Agreed. I find it to be awful in this respect. Wonderful on-road, indifferent over uneven surfaces, absolutely awful when hitting an unexpected rut at speed. KDSS disengaged (electrically modified so that the Stab Con ECU cannot exert control over the accumulator housing assembly) I can maintain my speed and course. With KDSS engaged (in the stock configuration) I have to swerve or slow greatly to address a rut so as to avoid jarring my occupants.

 

[jhguth]

can we please not be pedantic about engaged or disengaged and recognize that when people say it's "disengaged at low speed" it's obvious that someone means the hydraulics are open so the piston can move freely, and acknowledge that we all know this is what they mean, without needing to have a "well actually..." response please?

 

[Jetboy]

can we please not be pedantic about engaged or disengaged and recognize that when people say it's "disengaged at low speed" it's obvious that someone means the hydraulics are open so the piston can move freely, and acknowledge that we all know this is what they mean, without needing to have a "well actually..." response please?

There's a big difference between the two. It's not pedantic. Even your comment here is hard to know whether it's a misunderstanding or just imprecise description. A lot of people incorrectly think that the system is a sway bar disconnect. The pistons never move freely. They move in relation to the other piston. That's it. They never float or move independently. The sway bars never stop acting. And they never get softer. If people don't understand the difference how can there be a meaningful discussion? The effect on spring rates is complex. Using terms that mean different things is a problem.

 

[jhguth]

it's extremely pedantic, no one is confused

 

[jagsr71]

No matter what you do, a KDSS rig will never be buttery smooth, compared to a non-kdss rig.

People recommend kings because its the softest aftermarket shock vs other aftermarket shocks, but it will still be firmer than stock.

Don't expect miracles.


FYI, i run and recommend kings

Ditto. It's truly the best of both worlds w/ the Kings. I too run them and they're simply incredible. The difference between stock set up w/ KDSS and now w/ the Kings is worlds apart.
Because of KDSS, I don't experience the nose dive or leaning during corners. Then, with the addition of the Kings, the transformation really is noticeable. It's pretty damn near to buttery smooth.

 

[Jetboy]

it's extremely pedantic, no one is confused

So when you said the piston moves freely, what did you mean by that?

 

[jhguth]

So when you said the piston moves freely, what did you mean by that?

pedantic

 

[Jetboy]

No one knows what you meant. What you wrote is not accurate. The description of moving freely has a distinctly different effect from opening the shutter valves. As far as suspension design, it's a meaningful difference.

The comment 34 directly above says kdss prevents nose dive. Should we assume he meant something other than nose drive? Or that he doesn't understand kdss? Both can't be true.

 

[jhguth]

this is pedantry. feel free to argue with yourself, everyone else knows what everyone else is talking about

 

[GChristo]

Agree with Jetboy that precision in terminology is important and sometimes we are unclear. Edited my earlier post to reflect this.

 

[CoolMax]

I agree - shallow & pedantic.