Ripper238
Senior Member
Came across this video on how KDSS works. Very detailed and really makes me happy i got it.
https://www.youtube.com/watch?v=m3BnLLwbScA
https://www.youtube.com/watch?v=m3BnLLwbScA
Best video explaining KDSS
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Humble Leader
Senior Member
he does a great job explaining, good video. he needs to make a video on the XREAS and ATRAC now. although there are a couple good ones for ATRAC, I haven't seen a detailed XREAS one like this though. KDSS, XREAS and ATRAC seem to be common themed questions for prospective buyers
It is because of this video and understanding what KDSS does along with knowing I am not going to do a wild suspension upgrade, I went with KDSS on my order!
Ripper238
Senior Member
ATRAC and XREAS are definitely simpler to understand than KDSS, even our explanations are sufficient. But it would be cool to see him explain.
Best part is you can still do a ~2" lift with KDSS if you really wanted to.
I'm not a rock crawler but i like to do some normal offroading in the NE plus use my 4R as a daily driver. KDSS gives such great road manners and stock off road advantages its totally worth it for many. Just handles so well for a big SUV, going around bends is a pleasure with KDSS.
Toyota continues to impress me with the well thought out features and manufacturing quality.
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Yeah! I plan on doing about a 2" lift down the road. We have great trails right here in CO that I have explored extensively on dual-sport bikes, but plan on staying on the easy trails with this TRD Off Road. Not that it is not capable, just personal choice.
Ripper238
Senior Member
I'm planning on doing a lift when i hit 100k when i replace all the shocks. Just don't want the potential "lean" by doing so. Did you have to do any cutting to fit the 33's?
tifflieger
New member
I've read a lot of posts about KDSS trying to understand what it feels like on the road. It always seems to come down to something like, "It feels better" or "It drives better."
I'm trying to understand specifically how it feels or drives better on the road, not off road.
I'm trying to understand specifically how it feels or drives better on the road, not off road.
The video posted goes over exactly what it does on the road.
Primarily it's a super stiff roll stabilizing bar, so when you pull lateral G's the vehicle stays flat and level (relative to a non-KDSS vehicle of the same make/model/weight/lift/tires/etc.) instead of leaning at an angle. Basically it feels confident when in mountain twisties. It's still not a sports car by any means, but it is stiff and stable in the turns.
tifflieger
New member
A TRD Pro doesn't have KDSS; so what is it like in lateral Gs? Or does it have a suspension that compensates for no KDSS?
TRD Pro has different shocks/springs, but it doesn't compensate for no KDSS. Additionally with the slight lift that increases the CG and the bending moment that induces body roll and would therefore most likely be worse (unless the new springs are much stiffer than stock). The TRD Pro uses the same traditional anti-roll bar as the SR5 and Limited (which gets X-reas shocks from the factory).
I don't know that anyone has done the scientific comparison of measuring body lean angle at various lateral G's, but it would be interesting to know the numbers.
BlueRidge77
New member
This may be the best place to ask this… I’ve read conflicting things on here before. When does the system go “limp”? I think it’s below 12mph, but I’ve heard some say it must be in 4lo but others say no. I’ve never seen conformation. Right now, sitting in my drive way, is it limp? Allowing the pistons to easily move up and down?
BlueRidge77
New member
Thanks for the reference. Jetboy always knows his stuff. Now, I only know enough about this system to be dangerous… If the system is open all the time, then what purpose do the valves on the controller serve when performing lift installs? Or is that essentially just combining a “recal” of the system at the same time of lift install?
Here’s why I’m asking. I’m installing my Dobinsons lift on Thursday (finally…) and I want it to be as loose as possible to see if I can get it in without actually disconnecting the sway bars. Many seem to accomplish this… I don’t want to open the valve bolts because my driveway is not level and I don’t want to open them there. Thanks.
I wouldn't be too worried about opening the valves in the driveway, so long as you close them before you drive off. Then go find a level place to open the valves back up and level it out as best as you can.
While the system is 'open/relaxed' at low speeds etc, the front and rear piston are still hydraulically connected. If you were to lift the front driver and rear passenger at the same time, then the system would be balanced, but if you lift both driver side tires, the system will develop anti-roll stiffness regardless of the valve positioning. So there are kind of multiple combinations of electronics and natural loads that allow KDSS to operate.
There have been many different ways of dealing with KDSS lift installs over the years.
This guy has a walk through install of his KDSS 4R and I don't think he uses opens the valves and it should be the same with your Dobinson setup.
Toyota 4Runner 2020 with KDSS Front Lift with Ironman4x4 suspension - YouTube
Toyota 4runner with KDSS Rear lift Explain - YouTube
I installed my Eibach 2.0 coilovers without opening the valves. I just used a Jack to compress it while I worked on the opposite side and vice versa. It really wasn’t that hard to do imo. Just have multiple jacks that go high enough and you’ll be fine.
BlueRidge77
New member
That makes sense and kind of what I was thinking. Thanks.
Pretty much my plan. I’ve got a couple of jacks, lots of jack stands and some help. Thanks!
Blue109
New member
I ratchet-strapped the piston in place and unbolted the end links while the truck was on the ground, and then just did the lift like any other truck. After putting it back together, the passenger side sway link bolted up easy. I used a second ratchet strap on the driver's side to help pull it into place. It was cake. Had no issues at all.
I did NOT want to mess with the KDSS valves. Have maybe 1/4" difference hub to fender from left to right on the tape measure, but it's not noticable at all. Truck looks level to me.
I did NOT want to mess with the KDSS valves. Have maybe 1/4" difference hub to fender from left to right on the tape measure, but it's not noticable at all. Truck looks level to me.
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