KDSS vs Good Aftermarket Suspension

[cjdewese]

Another KDSS owner here as well. For me with how much of my driving is up and down windy roads KDSS has been awesome. The on road handling is fantastic and I find myself out pacing most other cars up and down the mountain and KDSS is a huge reason for that.

It is almost perfectly flat around corners even if pushing it fairly hard up and down the mountain. I have been impressed so far with nothing bad to say about the system.

 

[Toffees]

Who was the person who put the switch in to turn off KDSS? I was thinking about doing that but can't remember who it was

Sent from my SM-G930V using Tapatalk

 

[Brandonium]

Yeah, as far as I can remember it was discussed but never followed through with to completion. At least not to the point of others following suit. Perhaps I'm wrong though.

 

[Toffees]

Yeah, as far as I can remember it was discussed but never followed through with to completion. At least not to the point of others following suit. Perhaps I'm wrong though.

I took a quick read of that thread... then read up on KDSS (which is surprisingly similar to XREAS it seems)... and I'm no master in electronics and circuitry, but what did he want to do with a switch again?

 

[nb rob]

how is kdss even remotely related to xreas?

The switch was to allow for the movement of the pistons when they are normally in a locked position above 20kmph (12mph)

When they are locked, above 20kmph , the driver feels the benefit of the big swaybars.
When they are unlocked, additional movement is possible between LH and RH side, removing some of the negative aspects of having large swaybars when offroad.

 

[Jetboy]

I took a quick read of that thread... then read up on KDSS (which is surprisingly similar to XREAS it seems)... and I'm no master in electronics and circuitry, but what did he want to do with a switch again?

I think he wanted to leave the valves open above 12mph. More like the LC200 that's open all the time. I don't see any harm in doing that. They're basically just like any premium shock internally minus the valves. Someone had pictures from rebuilding one I've seen.

 

[Brandonium]

As I understand it he wanted to deactivate KDSS with the flick of a switch.

I took a quick read of that thread... then read up on KDSS (which is surprisingly similar to XREAS it seems)... and I'm no master in electronics and circuitry, but what did he want to do with a switch again?

 

[e60ral]

i don't understand your response, please explain

 

[Toffees]

I think he wanted to leave the valves open above 12mph. More like the LC200 that's open all the time. I don't see any harm in doing that. They're basically just like any premium shock internally minus the valves. Someone had pictures from rebuilding one I've seen.

As I understand it he wanted to deactivate KDSS with the flick of a switch.

I'm not a gearhead, I'm only qualified to break stuff, but that seems more complicated than needs to be

 

[Toffees]

i don't understand your response, please explain

Jetboy answered me above, but it seems unnecessarily complicated (or I'm an idiot.)

(Or both)

And although the system is "active", it's really a passive system. It activates based on changes in pressure. Seems odd you'd want to manually control a passive system, but I'm sure there are many examples of this working in real applications that I can't see.

 

[e60ral]

Jetboy answered me above, but it seems unnecessarily complicated (or I'm an idiot.)

(Or both)

And although the system is "active", it's really a passive system. It activates based on changes in pressure. Seems odd you'd want to manually control a passive system, but I'm sure there are many examples of this working in real applications that I can't see.

he didn't answer it, he was responding to your confusion

kdss works by allowing fluid to move under a certain speed and not allowing it to move above a certain speed. if you unplug the kdss module it will always allow the fluid to move, one user did that and was going to install a switch so they didn't have to remove a fuse or unplug stuff. i'm interested in doing the same thing so i flip a switch to turn off KDSS when i'm doing 20mph-ish on washboarded gravel roads.

does that clear things up? it's not completely passive, it turns on and off

 

[Toffees]

how is kdss even remotely related to xreas?

The switch was to allow for the movement of the pistons when they are normally in a locked position above 20kmph (12mph)

When they are locked, above 20kmph , the driver feels the benefit of the big swaybars.
When they are unlocked, additional movement is possible between LH and RH side, removing some of the negative aspects of having large swaybars when offroad.

KDSS uses gas and liquid pressures against each other to activate the system; since it's tied to all four wheels (at least in this installation, which I don't think is exactly what's in the 4R setup), it balances active wheels against non-active wheels (this is very technical language here...)

XREAS is much simpler, but similar idea; using 2 sets of linked reservoirs (oil only, no gas), it manages pressure on the wheel that needs it

The actual implantation and parts I'm sure are very different, but seems like the idea of each carries the same idea.*

*I'm sure an engineer will walk in and explain the manifold and varying differences between the two, but still the basic premise seems very similar

 

[e60ral]

^ [MENTION=144062]Toffees[/MENTION] watch this (your KDSS graphic isn't accurate):
https://youtu.be/NLF6n3nMwww?t=38

and KDSS is all hydraulic

 

[Toffees]

he didn't answer it, he was responding to your confusion

kdss works by allowing fluid to move under a certain speed and not allowing it to move above a certain speed. if you unplug the kdss module it will always allow the fluid to move, one user did that and was going to install a switch so they didn't have to remove a fuse or unplug stuff. i'm interested in doing the same thing so i flip a switch to turn off KDSS when i'm doing 20mph-ish on washboarded gravel roads.

does that clear things up? it's not completely passive, it turns on and off

It turns on an off based on pressure? Maybe passive is the wrong use of word. It responds automatically to driving conditions independent of user input?

 

[Toffees]

^ [MENTION=144062]Toffees[/MENTION] watch this (your KDSS graphic isn't accurate):
https://youtu.be/NLF6n3nMwww?t=38

and KDSS is all hydraulic

Same system, slightly different installation?

 

[e60ral]

It turns on an off based on pressure? Maybe passive is the wrong use of word. It responds automatically to driving conditions independent of user input?

speed

and in some conditions i want that speed to be higher, but not all the time so i want to install a switch

(i've read that the speed is 12mph but i don't know if that hs been confirmed. it's around that speed though for sure)

 

[e60ral]

Same system, slightly different installation?

the graphic you posted appears to be on shocks to replace an swaybar, very similar to XREAS, not KDSS

KDSS is a piston on the sway bar itself that allows it to articulate or not depending on if it is active

watch the video

 

[Toffees]

the graphic you posted appears to be on shocks to replace an swaybar, very similar to XREAS, not KDSS

KDSS is a piston on the sway bar itself that allows it to articulate or not depending on if it is active

watch the video

Video is the same*; gas/oil accumulators. The picture may actually be the Citreon design, that part is confusing to me. Same idea though

As always, from the ever reliable wiki:
AutoZine Technical School - Suspension
from https://en.wikipedia.org/wiki/Kinetic_Dynamic_Suspension_System

*Ok, so implementation is different--# of cylinders, etc, but seems like same idea to me; again, maybe I'm totally wrong.

 

[Toffees]

speed

and in some conditions i want that speed to be higher, but not all the time so i want to install a switch

(i've read that the speed is 12mph but i don't know if that hs been confirmed. it's around that speed though for sure)

that's the part i don't understand. does this involve installing a new reservoir to dump pressure so that it's inactive below a certain speed/pressure? if this is a mechanical/pressure system, where's the electric pump or is there a driveline driven pump? if there's no pump, then it's a sealed system, right? that's the part that makes me scratch my head.

 

[e60ral]

Video is the same*; gas/oil accumulators. The picture may actually be the Citreon design, that part is confusing to me. Same idea though

As always, from the ever reliable wiki:
AutoZine Technical School - Suspension
from https://en.wikipedia.org/wiki/Kinetic_Dynamic_Suspension_System

*Ok, so implementation is different--# of cylinders, etc, but seems like same idea to me; again, maybe I'm totally wrong.

no, that is not how it is installed in the 4runner, there is nothing side to side. what you posted is more similar to XREAS.

KDSS is front to back and then relies on thicker swaybars, the thicker sway bars are why it corners flatter the KDSS is what keeps them from articulating

watch the video

it's not a perfect comparison, but KDSS is kind of like a sway bar disconnect mixed with half of what you posted