I have stock coils all around with 2" spacers in the rear, and adjustable tundra bilstiens in the front cranked up a notch. When I hit several bumps in a row on the street, the rear end floats. If I am going around a corner and this happens, the rear ends slides over 6 inches or so on the road. Especially dangerous if it happens when I am panick stopping. I have the tundra bilstiens in the rear. I am thinking of getting the 4runner rear shocks bilstien has now, because I think the tundra ones are shot due to the floating. I noticed they have digressive valving. I like to be able to hit a big dip in the road, and feel the shocks soak it up without bottoming out. Will the digressive shocks do this? From what Ive read, it seems like they would be more likely to not soak it up and just hit the bump stops. I don't have any aftermarket bumpers or anything. Mostly street driven. I also want to go over a washboard road and stick to the road and not float and make it difficult to control the vehicle. I also don't want a overly harsh ride. Opinions?

Sounds like you want to have your cake and eat it too.

You asked quite a few questions here. I would check out this website
Shim ReStackor example calculation retuning a shim stack to be three clicks softer
It has tons of info regarding various valving theories.

To be honest, if you're looking for the top performance handling, you're gonna be dropping top performance money. Dampening is one of those things where you get what you pay for. The more you spend, the better your ride will be, as long as you know what you want your end result to be.

P.s. I'm not a big fan of digressive valving like that found in icons. My experience is that it makes the low speed bumps harsh.

I'm surprised their isn't more info and talk here about this.,a lot of people ask about shocks, seems they don't get into the technology much though.

The latter half of what you said is crazy in how right it is lol. Personally I have the OME 60073(4)? (Forgot which) in the rear. Idk the first thing of what kind they are but if you go slow over washboards they bounce you around like a boat on choppy water. If you go 15-20 you don't even feel them. That's no exaggeration I literally just felt like I was on a normal dirt road.


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It's my understanding that a digressive valving would be ideal for washboards. As that piston starts moving faster and faster with the high frequency of the impacts, the valving should soften, right, @4-Ripcord ??

The opposite would then be true for progressive... As the piston starts moving faster and faster, the valving should stiffen.

I will say that after riding in a long traveled 2nd gen Tacoma with King coilovers and shocks (progressive) and 35" tires on 16" wheels this past weekend, it didn't handle washboards any better than my 4Runner with Icon coilovers and shocks (digressive) and 33" tires on 17" wheels. I expected it to ride MUCH better with that massive sidewall, but such was not the case.

Was the 35's down aired? Bet at 15psi it would have ride awesome. Zero issues with wash board aired down.

It was just a short jaunt down a forest service road, so no. I don't typically air down for the same area and again, wasn't impressed.

I'm sure it'd be pretty sweet out in the desert though.

Picture of said Tacoma... Check out the new 16" SCS Stealth 6.

DSC_0161 by Alex Wilson, on Flickr

Thats a nice looking rig. Wife is about to get a 2016 TRD Pro, im trying to talk her into an older "cheaper" one. LOL.

My brothers ICON rig was not impressive at all either. I have not been impressed in any solid rear axle vehicle on washboard. That being in Fords, Chevy's, Toyota's or Jeeps. With OEM or any aftermarket suspension.

Only time I have done good on wash board was in a subaru or my DSM's. They would soak up the washboard and drift with ease. Fun days.

Agree with both.

I think Patio Burrito has it figured out, and is probably getting the best all around performance without going LT, (and even then there are compromises with LT). Toytec coils and King Shocks in the rear is what he's running.

And has also been said, air pressure is a big part of the equation as is tire weight, size and construction (C vs D vs E load rating).

There was a long thread on Race Dez a while back about why trophy trucks weigh so much, and it really comes down to tire size/weight. Bigger tires take more HP to turn (which leads to bigger cooling systems, etc.), bigger brakes to stop, bigger axle and gears, bigger suspension components to control the wheel travel...and so on. If you want to run a 40" tire it's going to affect everything else, same with our Runners on a diminished scale. It's complicated.

the best bang for the buck shock is a bilstien, I have them on my 4runner and wouldnt change a thing. also are you running a rear sway bar?

Having spent some time in a Raptor, I was very impressed at both washboard and high speed whoop control. For a factory rig you can buy on the showroom with a warranty, it's amazing.

Then there are the Ultra 4 cars that are SA at both ends. Now that takes some effort to make it work right.

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Good luck with this. As mentioned you will have to spend a lot of money to get your truck to feel decent on wash boards. Other than King and Icon, there is Fox, Camburg, toytec, and a few others that sell coilovers. My truck feels terrible on washboards. I love going off road but I absolutely hate the washboards.

And there are some threads that get pretty technical about custom shock valving here. I dont remember what they were called, but I remember reading them. You would have to search.

I wonder if watts linkage in the rear would make the solid axle handle washboards better. I think the panhard is a big part of the reason the rear gets out of control so much on washboards.

And, I might be the only person on the forum that feels this way, but if I could make my truck what I want it to be, it would be IFS long travel both front and rear. Thats right, IFS in the rear Everyone wants solid axles, and Im not entirely sure why. Ever been on a side by side? They are all ifs, and amazing at everything.My brother has a 2015 Can am Maverick, and we take it everywhere. Rocks, ruts, fast trails, washboars, it just eats up everything. And you can get all the flex and travel you need from IFS, and have the benefit of more center clearance than an axle. And of course the far superior handling dynamics on road and once you get going fast off road. anyways . . .

I think its mainly for strength. Locked cv shafts seem to break a lot easier than SA.

But I agree about IS being a lot better on washboard. My 400+whp talon was IS front and rear and it was a beast offroad.

I have bilstein 5100s at all 4 corners currently. Yes I am running a sway bar.