KDSS manual override?

[Toasty]

Has anyone tapped into the KDSS to override it manually (GX-470)? I haven't looked at it yet but as i understand it works by using hydraulic pressure created by the vehicle being crossed up offroad to open the system to sort of a free flow otherwise acting like a sway bar in all other situations. Anyway i'd like it to be "off" as soon as i leave pavement not just when it's needing to flex out. I've found that the system works well in deep ruts but otherwise makes the truck ride like a matchbox car offroad and totally sucks. I was thinking if i were to purge the system, braze in a bypass valve somewhere under the truck and recharge it would allow the oil or gas to move freely making the truck handle trail rides more comfortably (and faster). I could then open the valve at the trail head and have less of a sway bar effect and then close the valve once i'm back on pavement. Again i haven't even crawled under the truck to see if that's even possible or how the system works, i figured i'd ask first.

I know i could just remove and discard the KDSS but this is my daily driver and i don't want to seriously modify it, I want sway bars so my wife can drive the truck and i can tow if needed. Also i have a built Montero and a rock crawler Mighty Max already so the GX will stay stock except getting all terrains when the time comes.

Other than KDSS not being very cool off road i really like this truck and it performs pretty decent on the trail.

 

[Fishpilot]

Caveat: I have a 2011 4Runner Trail w/KDSS so my experience may be different.

The first thing you are going to do is void whatever warranty you have left and the second thing is you are going to incur a minimum of $1500-$1750 just to refill and pressurize the system assuming Lexus will even do that once you add a potential weak spot in a closed system. The KDSS is a time proven system for stability and reliability and is quite costly to fix/service IF it ever needs it, which tends to be rare.

I think you might have a slight misunderstanding of how it works. It is always "engaged", if you will, and does not require any build up of pressure to "activate" it. Just like a normal sway bar, it is working all the time, not just when you max out flex or hit triple digit speeds in a corner. If I understand you correctly you want to add a valve that you would only open off road. This would simply make it work like it always does, always working with fluid flowing based on terrain. There is nothing to open up for off road travel. Conversely, if you were to then close this valve and eliminate the ability of the fluid to move based on road conditions, I believe you would be running the most rigid suspension system on the planet based on fluid dynamics of a closed system. If you hit a bump and there is nowhere for that upward energy to be transmitted through the KDSS lines, then that force would be directed equally and oppositely back into the road causing wheel chatter and, I would assume, making the entire vehicle unsafe at any speed. You would essentially be blocking the entire KDSS system up during on road driving which is where the system works so well.

It doesn't limit your up/down travel any more than the stock shocks at full extension do by their inherent length, there are people who remove it totally but have yet to provide any actual measurements of increased flex. It improves the ride on road, and off road in my opinion, and like you mentioned will also benefit handling during trailering.

If your only complaint is that it rides like a matchbox car, which I assume you mean it is very stiff, when you are off roading have you checked other possible contributing factors? If you are running E rated tires and running them at the higher PSI that most people do (38-42psi vs ~36 for C) and you aren't airing them down at all when you head off pavement, then those are all things that could contribute to a perceived harsh ride on rough terrain. Any suspension mods you might have done are factors as well, I have no idea what your rig is running but that's an obvious factor. You mentioned the need for speed during off road runs, remember this isn't a ford raptor with dual/remote reservoir high capacity coil overs, its a heavy SUV that will never ride like a desert racer.

Keep us posted on any KDSS mods.