Shock Tech

[AssBurns]

Re-valved the rear shocks tonight. I basically just added a thin 37.4mm x .20mm shim (equal to about 1.5" x .008") to the compression stack above the 18mm x .15mm bypass plate to give it a little bit of a flutter. I hoped that the added shim keeps a nice light initial slow speed valving while making the rest of the mid to high speed valving firmer. I took it for a short test drive and it pretty much worked out as expected. Overall its a little firmer across the board which feels pretty nice. Now the front needs to get the same treatment before I go back to the rear again. I think I may end up going a little firmer depending how it feels with the fronts re-valved and bump stops get destroked.

 

[Stairgod]

Didn’t know you could use Argon for shocks. Guessing it doesn’t expand with heat like nitrogen?

I don’t have an argon tank so I’m at square one with all this.

Doubt either gasses expand much with heat. Their boiling points are quite similar iirc, so they would likely be near identical in that regard despite the rather large disparity in their atomics weights.
I won't say that Argon is better than Nitrogen due to its inert nature because in this application Nitrogen is essentially inert also. Main benefit is that Nitrogen is much cheaper. But unless you are constantly filling shocks, I can't see it being a large difference in expense.
Since you needed a tank anyway, Nitrogen makes more sense for you.

 

[AssBurns]

Picked up some shims from Icon today. I really wasn't sure what was in there and wasn't sure what I needed. I just asked the sales guy to give me some shims to mess around with and help me figure out what I need. Well he probably had no idea what was in there so I pretty much got a bunch of 1.55" and 0.925" shims in various thicknesses. I needed more of some stuff in the middle too in thicker sizes. I didn't want to mess with rebound yet so I only changed compression. I got creative with it just to see what it feels like with different changes. It came with a flutter stack already, and I just modified it.
For the low speed compression I thinned out the second shim, and added a wider shim behind it, then did a thinner shim as the fulcrum shim for the flutter. I thickened the the first shim after the flutter.
For the high speed compression I thickened the last shim, and added another one below it. I don't think this was the right idea but I wanted to try it. I think this ended up doing the opposite of what I wanted which is to stiffen things up a bit. I think the smaller diameter shim basically acts as a final fulcrum for all the shims to pivot against. So with a narrower fulcrum and more space between the widest shim and the rate plate ended up letting more flow through the piston. I think I am going to try pulling that smallest shim and seeing how it feels.
Right now speed bumps and dips feel more balanced with the rear but on the hard hits it feels soft still. I think I'll leave the slow speed shims how they are, then pull the last high speed shim out, and swap shim #11 with a thinner one.

 

[Stairgod]

Picked up some shims from Icon today. I really wasn't sure what was in there and wasn't sure what I needed. I just asked the sales guy to give me some shims to mess around with and help me figure out what I need. Well he probably had no idea what was in there so I pretty much got a bunch of 1.55" and 0.925" shims in various thicknesses. I needed more of some stuff in the middle too in thicker sizes. I didn't want to mess with rebound yet so I only changed compression. I got creative with it just to see what it feels like with different changes. It came with a flutter stack already, and I just modified it.
For the low speed compression I thinned out the second shim, and added a wider shim behind it, then did a thinner shim as the fulcrum shim for the flutter. I thickened the the first shim after the flutter.
For the high speed compression I thickened the last shim, and added another one below it. I don't think this was the right idea but I wanted to try it. I think this ended up doing the opposite of what I wanted which is to stiffen things up a bit. I think the smaller diameter shim basically acts as a final fulcrum for all the shims to pivot against. So with a narrower fulcrum and more space between the widest shim and the rate plate ended up letting more flow through the piston. I think I am going to try pulling that smallest shim and seeing how it feels.
Right now speed bumps and dips feel more balanced with the rear but on the hard hits it feels soft still. I think I'll leave the slow speed shims how they are, then pull the last high speed shim out, and swap shim #11 with a thinner one.

View attachment 22078

Trying to make sense of that gave me a headache...lol
Seems to me that #7 & #8 make a very harsh zone, no?

 

[AssBurns]

Trying to make sense of that gave me a headache...lol
Seems to me that #7 & #8 make a very harsh zone, no?

I'll have to take a pic of the layout for better visual understanding. It's hard to "see" what is going on with those numbers.

#7 & #8 shims were already there from the stock configuration and I didn't have enough shims to mess with the mid speed zone so I left it as is. Not really sure what needs to be done there or if I should change it up. I am going to try to pick up some thicker shims for the middle of the stack. Once I have more shims, I'll be able to really change things up. I am still learning a lot and making small changes where I think things are needed, but I am likely way off.

 

[AssBurns]

Also just found this resource for shock valving and dampening. Super helpful info.

Stack Styles

Damping Profiles

 

[Stairgod]

I'll have to take a pic of the layout for better visual understanding. It's hard to "see" what is going on with those numbers.

#7 & #8 shims were already there from the stock configuration and I didn't have enough shims to mess with the mid speed zone so I left it as is. Not really sure what needs to be done there or if I should change it up. I am going to try to pick up some thicker shims for the middle of the stack. Once I have more shims, I'll be able to really change things up. I am still learning a lot and making small changes where I think things are needed, but I am likely way off.

I am a complete novice when it comes to valving, and I better get learning because my shit needs to be rebuilt and I have never been happy with the valving.

 

[Stairgod]

Also just found this resource for shock valving and dampening. Super helpful info.

Stack Styles

Damping Profiles

Thanks for that huge rabbit hole

 

[Dezert4Runner]

Picked up some shims from Icon today. I really wasn't sure what was in there and wasn't sure what I needed. I just asked the sales guy to give me some shims to mess around with and help me figure out what I need. Well he probably had no idea what was in there so I pretty much got a bunch of 1.55" and 0.925" shims in various thicknesses. I needed more of some stuff in the middle too in thicker sizes. I didn't want to mess with rebound yet so I only changed compression. I got creative with it just to see what it feels like with different changes. It came with a flutter stack already, and I just modified it.
For the low speed compression I thinned out the second shim, and added a wider shim behind it, then did a thinner shim as the fulcrum shim for the flutter. I thickened the the first shim after the flutter.
For the high speed compression I thickened the last shim, and added another one below it. I don't think this was the right idea but I wanted to try it. I think this ended up doing the opposite of what I wanted which is to stiffen things up a bit. I think the smaller diameter shim basically acts as a final fulcrum for all the shims to pivot against. So with a narrower fulcrum and more space between the widest shim and the rate plate ended up letting more flow through the piston. I think I am going to try pulling that smallest shim and seeing how it feels.
Right now speed bumps and dips feel more balanced with the rear but on the hard hits it feels soft still. I think I'll leave the slow speed shims how they are, then pull the last high speed shim out, and swap shim #11 with a thinner one.

View attachment 22078

What did you use to take your coils off? Low end threaded rod style spring compressors aren’t made to fit the thicker coils and also don’t fit inbetween the coil and body of the shock on 2.5’s. The $100-200 stand up style ones look like really thin flimsy metal and I don’t trust them around heavy duty springs either. I want to rebuild my SAW’s and change the 13” 650 lb coils out for some 14” 600 lb sitting in the garage. A Branick would be nice but not for $800 lol. They’re also impossible to find used locally I’ve come to find out.

 

[AssBurns]

Thanks for that huge rabbit hole

Right? lol

What did you use to take your coils off? Low end threaded rod style spring compressors aren’t made to fit the thicker coils and also don’t fit inbetween the coil and body of the shock on 2.5’s. The $100-200 stand up style ones look like really thin flimsy metal and I don’t trust them around heavy duty springs either. I want to rebuild my SAW’s and change the 13” 650 lb coils out for some 14” 600 lb sitting in the garage. A Branick would be nice but not for $800 lol. They’re also impossible to find used locally I’ve come to find out.

With the proper length coils, you shouldn't need a tool to remove the coils. Just back off the preload nut until its loose and slide off the coil retainer cup, then slide off the coil. Super easy. If you are running coils that are longer than what the shock was designed around, then you'll have to get a tool to compress the coils enough to slide the retainer cup out. While a taller softer coil is usually better than a short stiff coil. You shouldn't get too long of a coil because the coil can block out (coil bind) at full compression which is not good at all.

Why do you want a taller coil? More lift?
If you have enough lift without a shit ton of preload, then you shouldn't need taller or stiffer coils. On my coilovers, I have about 1.5" of preload (about 2" of threads showing on the shock body). You should have at least an inch of actual preload. (not just threads showing) To measure preload, you need to back off the preload nut until the coil is at its free height (not loose and not compressed). That is ZERO preload. Measure the distance from the top cap to the preload nut to get a baseline for where preload starts with those coils. Start with an inch of preload and go more if you need more lift. If you have to crank it down a lot more than an inch or so, you may need stiffer coils. I am about 1.5-1.625" of preload on mine with 600# springs which gets me probably somewhere between 2-3" of lift. I don't feel the need to get a stiffer or taller coil with that amount of preload. I probably wouldn't go more than 2 inches of preload though. You can probably search the block height of the coils you have to see how much you can crank the preload down without coil bind.

 

[4runner DOA]

Right? lol

With the proper length coils, you shouldn't need a tool to remove the coils. Just back off the preload nut until its loose and slide off the coil retainer cup, then slide off the coil. Super easy. If you are running coils that are longer than what the shock was designed around, then you'll have to get a tool to compress the coils enough to slide the retainer cup out. While a taller softer coil is usually better than a short stiff coil. You shouldn't get too long of a coil because the coil can block out (coil bind) at full compression which is not good at all.

Why do you want a taller coil? More lift?
If you have enough lift without a shit ton of preload, then you shouldn't need taller or stiffer coils. On my coilovers, I have about 1.5" of preload (about 2" of threads showing on the shock body). You should have at least an inch of actual preload. (not just threads showing) To measure preload, you need to back off the preload nut until the coil is at its free height (not loose and not compressed). That is ZERO preload. Measure the distance from the top cap to the preload nut to get a baseline for where preload starts with those coils. Start with an inch of preload and go more if you need more lift. If you have to crank it down a lot more than an inch or so, you may need stiffer coils. I am about 1.5-1.625" of preload on mine with 600# springs which gets me probably somewhere between 2-3" of lift. I don't feel the need to get a stiffer or taller coil with that amount of preload. I probably wouldn't go more than 2 inches of preload though. You can probably search the block height of the coils you have to see how much you can crank the preload down without coil bind.

Taller coils require less preload typically. I went from a 13" to a 14" on my icons because I had a ton of preload.

 

[AssBurns]

Taller coils require less preload typically. I went from a 13" to a 14" on my icons because I had a ton of preload.

Preload is a good thing though. Keeps a consistent tire contact with the ground under droop. With little to no preload, there is nothing holding your tire firm to the ground at full droop. No preload mean the spring rate is effectively zero at full droop, which makes things inconsistent.
And a taller coil will still require the same amount or more preload than a shorter coil. You will just have less threads showing which is NOT what preload is. With a taller spring you'll have to preload it just to get it on the shock, whereas a shorter spring will slide on with no preload. Either way you'll need XX amount of preload to set your desired height. A taller spring just makes it where its not cranked down on the shock body so much.

So with say a 650# coil needs 1" of preload for three inches of vehicle lift height. Doesn't matter if you have a 13" x 650# or 14" x 650# coil, you'll still need roughly the same 1" of preload for three inches of lift.
Now the way it fits on your shock is different. With a 13" coil at 1" preload, you may have 1.5" of threads showing, whereas a 14" coil only has 0.5" of threads showing. Either way you still have 1" of preload for either coil.

 

[4runner DOA]

I also went from 650s to 700s. So I actually had less preload going from a 13 to a 14. Haha.

 

[AssBurns]

I also went from 650s to 700s. So I actually had less preload going from a 13 to a 14. Haha.

Well spring rate will most definitely change preload. Going to a 14" just makes it much more difficult to pull apart your shocks lol.

Any idea how much preload you have? An easy way to check is jack up the truck till you are at full droop and measure the coil height. Subtract that number from 14" and you'll know your preload. I am curious how much you have since 700# is a lot, but you also have a lot of weight.

 

[4runner DOA]

Well spring rate will most definitely change preload. Going to a 14" just makes it much more difficult to pull apart your shocks lol.

Any idea how much preload you have? An easy way to check is jack up the truck till you are at full droop and measure the coil height. Subtract that number from 14" and you'll know your preload. I am curious how much you have since 700# is a lot, but you also have a lot of weight.

I'll have to look when I'm swapping out my control arms.

 

[Dezert4Runner]

I’m going from 650 13” to 600 14” and the 1” longer coil means I can back off the collar more than I would with a 13” 600 coil and still achieve the same lift while preserving ride quality in the process. I don’t know what the preload is on the 13” coil itself, but I have 2” of threads showing for 3” or lift and want a softer coil without cranking the collar to like 2.25” or 2.5” of threads showing and diminishing ride quality.

 

[AssBurns]

HUGE improvement today!
Totally changed up the valve stack. Eliminated the flutter bullshit. I've been doing some reading and watching some videos on valving. Sounds like flutter stacks at not near as great as people make them up to be.
Since the piston is a digressive piston, it has a preload shim. Thinner the shim means more preload, which makes it more digressive. It had a .015" preload shim, and I swapped it for a .018" preload shim in hopes to make it less digressive and more linear/progressive.
Instead of having a flutter stack, I thickened up the main shim from .015" to .018" and pulled the crossover/flutter shim.
On the second set of smaller diameter shims I added second 1.425" x .015" shim behind the existing one; doubling it up.
The rest of the shims till the last shims stayed the same. The very last shim that I added last night got pulled and the current last shim got swapped out for a thicker shim (Was .015". Now .018") The reason to remove the last narrow diameter shim is it widens the fulcrum point of the stack, therefore stiffening things up.
Rebound remained the same once again.

So now it feels really good on the smaller stuff on the road. No noticeable difference in handling, but the chatter on the small bumps and potholes feels much smoother. Last night it felt much choppier in the potholes and washboard type stuff.
The medium stuff such as speed bumps and big dips feels much firmer, but not jarring at all. I have to get used to this, but feels good.
The bigger stuff such as ruts, jumps, and curbs feels much better soft and smooth like it should be but firm enough to not easily bottom out. I hit some decent dips a dirt road down the street and even got the front wheels off the ground on a lip a wash crossing, and it felt much better. Stayed off the bumps really well, but definitely hit bumps when hitting things hard enough.
Overall I am much happier with it now. Might have to do something similar in the rear, but I want to test it out with at least a few hours of wheeling before making any changes.

 

[AssBurns]

Another great source I found today. Definitely worth watching. Not only does he talk about some great stuff, but he shows shock dyno results showing certain changes.

The Ohlins Guy

 

[Arcticelf]

Doubt either gasses expand much with heat. Their boiling points are quite similar iirc, so they would likely be near identical in that regard despite the rather large disparity in their atomics weights.
I won't say that Argon is better than Nitrogen due to its inert nature because in this application Nitrogen is essentially inert also. Main benefit is that Nitrogen is much cheaper. But unless you are constantly filling shocks, I can't see it being a large difference in expense.
Since you needed a tank anyway, Nitrogen makes more sense for you.

N2 is about half the price of Ar, so it makes sense for King and Fox. I can't see any reason not to use Ar if that's what you have though, so I use it. They are both Nobel gasses, but Ar is a bigger and heavier molecule.

 

[Toxicity927]

Lots of good info!

Does anyone have experience with bilstein 8112 or 8100?

I’m looking to do a major upgrade from my 5100’s.