What’s REEAALY going on inside shocks

from everything I’ve read here and elsewhere: fancy looking suspension = good suspension, and not fancy looking = save your money for something pretty.

I understand that reservoirs dissipate heat better than non res, but by show of hands who owns reservoirs but only see 95% highway. It seems like all of the suspension threads are one of two questions mainly based off of budget:

OME or 5100

OR

King, Fox, icon

Poll #2 who can raise their hand and say that they have tried them all in multiple terrain after being tuned CORRECTLY. I know I know none of us have except maybe the hardcore 2% who have a pre-runner AND a race truck (they’re probably biased anyways)

SO

can we discuss the INTERNALS and operation of everything out there

*Are 2.0 and 2.5 valued the same?
*Does the diameter really matter?
*What shocks can be rebuilt?
*What shocks have adjustable valving (take apart and send in, or mess with the clicky nob)
*The new internal bypass shocks vs external bypass (why the haters on the new billstein 81-whatever’s)
*What does it REALLY mean when your suspension “fades”?
*What do you have to do to these shocks to notice them fading?
*Can bumpstops act as a 3rd tube of a bypass shock (when used with an adjustable compression/rebound setup or at least a progressive spring rate?
*high/low speed adjustability, what’s high and what’s low?
*What does a guy need to know to go: “hey! I need limit straps”?
*What effect does a sway-bar have on shock performance?
*what things are overlooked that would alter suspension performance?
*why would someone prefer digressive valving for off-road?
*what category (based on internals) do 6112s fall into?


I know “all depends on preference, intended use, and budget”.

But let’s pretend I have gobs of money but I’m just a nerd trying to find the best bang for my buck. Meanwhile I’m one of those rich nerds who can’t justify a tiny upgrade in performance if it costs $xxx.

Not really looking to hear “what you have and rides great” are there any suspension wizards out there.

And why the heck did they run 2 shocks back in the day?

 

Sub'd for the wizardry responses.

 

Aaaaaaanybody?

 

subd

 

https://www.youtube.com/watch?v=-MsKf1lIYI0

 

I was expecting a cool video of the internal parts of shocks working over rough terrain.

 

Sub'd

 

I have zero experience with suspension. That said, what I can tell from reading is that icon/king is if you wanna go fast off road...OME if you want better offroad capabilities than stock with better weight handling (bumpers, winches, etc) and getting a lift. Then bilsteins as basic ride/offroad improvements without increase weight carry abilities or lift.

 

@Cirdan so if you dressed up regular OME nitrochargers to have a threaded body, rebuildable, and shiny anodized stuff. Would you have kings? Do regular king coilovers really perform that much better. After all, these guys (if I understand correctly) just use them for coil carriers, and leave the sweet sweet off road magic to the bypass shock:

 

*Why Remote Reservoirs:
Reservoirs are not really about heat dissipation, they're about reducing the internal gas pressure. That reduces friction, improves ride quality, is easier on seals, and improves the life of the shock.


*Are 2.0 and 2.5 valved the same?
Yes and no. It all depends on specific design and there are a lot of little intricate pieces to this, but let's summarize. 2.0's have less cross sectional area than 2.5's, so they'll inherently make less damping. So there are ranges where 2.0's are more tuneable, and ranges where 2.5's are more tuneable, and a range where both are tuneable. Tacoma's really need 2.5's in the front to be useful offroad, 2.0's don't make enough force so they're either soft or you have to use tricks to make them stiffer which sometimes result in harshness, but we're sort of getting beyond a summary if we dive into that.

*Does the diameter really matter?
In addition to making more damping force, larger shocks operate at lower pressures, and can candle more heat. In the front of Tacoma's you need the damping force. If you're running washboard hard you need the heat capacity in the rear.

*What shocks can be rebuilt?
If that shock has a port for charging there's a 90% chance it can be rebuilt.

*What shocks have adjustable valving (take apart and send in, or mess with the clicky nob)
This needs its own list

*The new internal bypass shocks vs external bypass (why the haters on the new billstein 81-whatever’s)
There are multiple ways to accomplish internal bypass, I'll cover the most popular three.
Bottoming cups have a second piston that engages at bottom out (Bilstein, and many motorcycle shocks). This works well when the mounts can handle it and there's no room for a separate bump stop.
Bottoming needle (King) has a needle that shuts off oil flow at bottom out. Difficult to tune because it really requires a lathe, usually a complex design.
Twin tube with ports (Fox) has many zones just like an external bypass. Has less damping area (lower force) and slightly less oil, but works well.

External bypasses are always preferable to internal bypass, they're easier to tune, make more damping force, and are usually much simpler. Plus you end up with way more shock (oil and damping capability).


*What does it REALLY mean when your suspension “fades”?
As oil gets hot the viscosity decreases and it stops making as much damping.

*What do you have to do to these shocks to notice them fading?
More than 5 min of go fast driving through whoops or big washboard will lead to fading of 2.0's on the rear of a Tacoma. Although that's a general rule of thumb, others may have different experiences.

*Can bumpstops act as a 3rd tube of a bypass shock (when used with an adjustable compression/rebound setup or at least a progressive spring rate?
Yes and no, the third tube and bump stops both work to stop bottoming, but the way they function is very different.
In a proper setup (overlapping tubes) the third tube greatly increases tuneability and allows a bigger split between ride and bottom out zones.
The bypass shock also works completely off damping which is speed sensitive. There is also some limit in how much bottoming control you can get out of a bypass, bigger shocks = more bottoming resistance.
Air bumps have some damping and some air spring which is position sensitive.
So both work to prevent bottoming, but they do it a bit differently.

*high/low speed adjustability, what’s high and what’s low?
Low speed compression is bottoming out on rollers and g-outs, and also handling.
High speed compression is bottoming (or jaring) on square hits and whoops.
This article & video explains a lot of that: http://accutuneoffroad.com/articles/digressive-vs-linear-vs-progressive-pistons-shock-valving/

*What does a guy need to know to go: “hey! I need limit straps”?
If the shocks aren't designed to top out, and they are expensive, you should spend $20 on limit straps.
Most bolt on Tacoma shocks were designed to run without limit straps.

*What effect does a sway-bar have on shock performance?
In the perfect world shocks and springs are setup to provide ride comfort and performance over bumps then add sway bar as necessary for handling.
With Tacoma's the stock sway bar tends to be stiff and have a lot of friction, both of which ruin ride quality.
The ride in my old Tacoma (Donahoe, Deaver, Fox) was much better with the sway bar off, so in Tacoma's they tend to be too stiff because they don't adequately let the the tires move independent of each other, making your ifs act a bit more like a solid axle on vertical bumps.

*what things are overlooked that would alter suspension performance?
I think most people are daily driving near stock weight Tacoma's but looking to heavy overland rigs for suspension setup.
As a result they're ruining ride quality with way too stiff of a suspension.
I also see A LOT of bandaids for incorrect shock valving and spring setup that prevent bottoming out, but ultimately ruin ride quality.

*why would someone prefer digressive valving for off-road?
They wouldn't, and note that in my experience Icon runs a digressive piston, but it appears to be tuned to perform in a fairly linear fashion.
http://accutuneoffroad.com/articles/digressive-vs-linear-vs-progressive-pistons-shock-valving/

*what category (based on internals) do 6112s fall into?


And why the heck did they run 2 shocks back in the day?
Because bigger shocks weren't available.
Because big shocks were more expensive and they found two small ones for less.
Because it looked cool.

 

Awesome @*TRD*, That answers so much. Really appreciate it.

 

dayumm @*TRD* ... You are a true wizzard! Thanks for the info.

@doorsidedown a good read.

 

Nice.

 

Would someone mind commenting on how the discs work in conjunction with the piston, what happens on compression, what happens on rebound. And per the second accutune video which side represents the shaft side (piston and shaft are connected right?).

I’m betting this is a very broad question.

 

Shocks work based on pressure drop over the piston. Pressure * Area = Force
Port size and disk stiffness work together to control how high the pressure is, piston diameter (actually body ID) controls the area.
The disks bend and allow oil to flow.
Either side could be the shaft side.

I'm the one in the video...

 

just going to put this article that I found on another thread, for anyone who is going down the rabbit hole with me:

http://www.4x4review.com/everything-you-wanted-to-know-about-shock-absorbers/

 

i've got ICON 2.5 up front which are great and running 2.0 in the rear. I've since added more weight to the rear and will be upgrading the leaf pack -- the question is will the upgraded leaf pack be enough for the 2.0 in the rear or do I need to add 2.5 in the rear?