Understanding Suspension Damping

There seems to be some misunderstanding about what that little knob on adjustable shocks does. This will be a vary basic explanation of damping.
 
The function of shock absorbers is to dissipate the the kinetic energy created by the compression and rebound of the springs. Without damping a car would continue oscillating up and down after hitting a bump (we've all seen cars with blown shocks bouncing down the road).
 
There are two directions of damping; compression (down) and rebound (up). 
 
Compression damping is resistance to the spring compressing. It is not adjustable in some adjustable shocks. Compression damping is broke down into two sections; high and low speed. "Speed" refers to the velocity at which the piston is moving. Low speed means the piston is moving in slowly (body roll, etc.), high speed is the opposite (shap impacts).
 
Rebound damping is resistance to the spring extending to it's original length. It is much higher because the spring stores energy in a compressed state. 
 
A lot of people I talk to seem to be under the impression that damping controls the stiffness of the ride, and that more is better. While compression damping can have an effect on suspension travel, this is the job of the spring/air spring for the most part. It is also important to realize that unless you are running coilovers with independent compression and rebound adjustment (you're not) then you will be affecting rebound damping simultaneously, if not solely.
 
I get a lot of guys who want to run bags over coils asking for high spring rate setups (where the valving will be matched). Chances are you are not dailying your bag setup at a PSI equal to a high teen spring rate so you will only be over damping the bag. Over damping the compression will limit the travel, however over damping the rebound will keep the shock from fully extending. This means that when you hit repeated bumps your car will gradually lower; defeating the purpose of trying to go "stiffer" via damping, which is to keep the car off the ground. This is why matching is important.
 
As usual, more is not necessarily better. If you want a stiffer ride do it via spring rate/PSI. Damping should be matched not used independently.

Good explanation! :biggthumpup:

Then what would be the solution to a person that is going to run static? Would it just be having higher spring rates like 18k/20k with the regular dampening? Or would you have to adjust the dampening accordingly?

When you order custom rate coilovers they should be valved appropriately. If you already own coilovers you are stuck with a +/-2k spring rate without having them revalved.

Informative!!!! Well explained!

I see. Thanks OG!

that's some OG shit right there.

Good stuff! Thanks OG

good explanation OG...   explains pretty much everything.   How does stiffening or softening the little knob affect driving while tracking?   I never learned that part and left everything in the middle.

It's all about finding the sweet spot. There are negative affects on both sides of the spectrum (high and low). My guess is that a true track car uses the adjustments to dial the damping in and adjust for variations from track to track. Seeing as I don't build track cars I kind of drop off where the info stops being relevant.

[QUOTE=OG;434807] Seeing as I don't build track cars I kind of drop off where the info stops being relevant.[/QUOTE]
 Props for no bullshitting..... 


So what I am getting is that if my control arm is hitting the shock tower in my GS, Then cranking the damping knobs to full stiff on my BC coilovers is not the way to go about solving the problem. And also what I am getting is that you ideally want to have the valving matched with the springs. And then use the damping to find the "sweet spot" in said setup. Anyways good post, good to keep the info coming.

[QUOTE=~~sperm~bomb~~;434824]So what I am getting is that if my control arm is hitting the shock tower in my GS, Then cranking the damping knobs to full stiff on my BC coilovers is not the way to go about solving the problem. And also what I am getting is that you ideally want to have the valving matched with the springs. And then use the damping to find the "sweet spot" in said setup. Anyways good post, good to keep the info coming.[/QUOTE]
 
:biggthumpup:

I've read that some Japan guys run ridiculously high spring rates on their static coil vip cars, like in the 30-40k range. I've always wondered what the Japan guys do as far as valving when they do this (assuming its true). My guess is, the spring is so stiff there is little to no suspension travel, so the valving wont matter because the strut does not really travel. What do you guys think? I'm also guessing it must ride really really harsh with that kind of setup, but I guess it kind of makes sense (in an extreme way) if you want that "look" and dont want to smash the fenders (aka no suspension travel)

When I bought my coils (JIC), it was through a retailer, so there was no mention of the spring rates or valving. I'm assuming there are some coil manufacturers that will work with the customer directly for some kind of custom setup, but I'm kind of at a loss how the Japan guys go about doing it. Do Japan brands allow this? Does the customer just tell the manufacturer the spring rate they want, and the manufacturer figures it all out? So far I've only read about BC doing custom, which (I believe) is somewhat new to the game and not a Japan brand. Since this thread is about the tech side of choosing / adjusting the coils, can anyone that has experience with custom rates / valving list some names of the manufacturers (brands) that you worked with? Kind of sucks if we (USA) are stuck with prepacked or custom but mismatched (in terms of rate / valving) Japan brand setups if we dont speak Japanese or just dont know who to talk to.

When I eventually do my cup setup I'm planning to drive low so I'm going to want a stiffer spring setup with matched valving. But everything kind of seems "unknown" as far as rates and valving when you go through traditional means of researching brands and products (using the general marketing info released to the public)

Id like to know as well, iv never herd anyine say oh i got this spring with valveing to match. something to think about if i up my coils someday.
 
 
[QUOTE=CrazyHawaiian;435974]I've read that some Japan guys run ridiculously high spring rates on their static coil vip cars, like in the 30-40k range. I've always wondered what the Japan guys do as far as valving when they do this (assuming its true). My guess is, the spring is so stiff there is little to no suspension travel, so the valving wont matter because the strut does not really travel. What do you guys think? I'm also guessing it must ride really really harsh with that kind of setup, but I guess it kind of makes sense (in an extreme way) if you want that "look" and dont want to smash the fenders (aka no suspension travel)
 
When I bought my coils (JIC), it was through a retailer, so there was no mention of the spring rates or valving. I'm assuming there are some coil manufacturers that will work with the customer directly for some kind of custom setup, but I'm kind of at a loss how the Japan guys go about doing it. Do Japan brands allow this? Does the customer just tell the manufacturer the spring rate they want, and the manufacturer figures it all out? So far I've only read about BC doing custom, which (I believe) is somewhat new to the game and not a Japan brand. Since this thread is about the tech side of choosing / adjusting the coils, can anyone that has experience with custom rates / valving list some names of the manufacturers (brands) that you worked with? Kind of sucks if we (USA) are stuck with prepacked or custom but mismatched (in terms of rate / valving) Japan brand setups if we dont speak Japanese or just dont know who to talk to.
 
When I eventually do my cup setup I'm planning to drive low so I'm going to want a stiffer spring setup with matched valving. But everything kind of seems "unknown" as far as rates and valving when you go through traditional means of researching brands and products (using the general marketing info released to the public)[/QUOTE]

[QUOTE=CrazyHawaiian;435974]I've read that some Japan guys run ridiculously high spring rates on their static coil vip cars, like in the 30-40k range. I've always wondered what the Japan guys do as far as valving when they do this (assuming its true). My guess is, the spring is so stiff there is little to no suspension travel, so the valving wont matter because the strut does not really travel. What do you guys think? I'm also guessing it must ride really really harsh with that kind of setup, but I guess it kind of makes sense (in an extreme way) if you want that "look" and dont want to smash the fenders (aka no suspension travel)
 
When I bought my coils (JIC), it was through a retailer, so there was no mention of the spring rates or valving. I'm assuming there are some coil manufacturers that will work with the customer directly for some kind of custom setup, but I'm kind of at a loss how the Japan guys go about doing it. Do Japan brands allow this? Does the customer just tell the manufacturer the spring rate they want, and the manufacturer figures it all out? So far I've only read about BC doing custom, which (I believe) is somewhat new to the game and not a Japan brand. Since this thread is about the tech side of choosing / adjusting the coils, can anyone that has experience with custom rates / valving list some names of the manufacturers (brands) that you worked with? Kind of sucks if we (USA) are stuck with prepacked or custom but mismatched (in terms of rate / valving) Japan brand setups if we dont speak Japanese or just dont know who to talk to.
 
When I eventually do my cup setup I'm planning to drive low so I'm going to want a stiffer spring setup with matched valving. But everything kind of seems "unknown" as far as rates and valving when you go through traditional means of researching brands and products (using the general marketing info released to the public)[/QUOTE]
 
tech info on the extreme spring rate subject is going to be limited, because what we do is actually limit suspension whereas the technical research is all about maximizing suspension function. i can conclude, from personal experience, that proper valving is essential to ride quality though. the high rate bc setups i install ride better than some of the lower rate out-of-the-box setups from other companies (not all, just some). the process of elimination leaves only one variable.
 

until recently, you didn't really get into custom options untiil you started talking full race spec coilovers ($$$). the option for high end custom coils is and has always been there, just not at the price point it is now. at one time i wanted to provide some of these options, but the market is non-existent. vip cats just don't want to spend $2k+ on coils when there is at least one quality $1K option. truth be told, there's no reason to. even the jic you purchased were bought at a clearance price that was under dealer cost when they were current.

i've heard that k-spot, d2, megan, and stance will all do custom rates but the only time i deal with these brands are when they're brought in. powered by max will sell you seperate parts to convert the coils you just bought (?). bc offers "extreme drop" specs and will do whatever else you want at no additional cost. jic japan has the "super low" and "ground zero" lines, but never imported them. when they were assembling remaining japanese stock stateside i actually got jic to agree to some silly rates/valving but i'm not sure what they're going to do with u.s. production. tanabe has the super low line, which isn't imported and has extemely limited application. companies like zeal, moton, ohlins, etc. offer custom specs; but the price is high and the applications also limited. i guess the moral of the story is there's a lot out there, just not many direct connections to it because it's not marketable or applicable.

[QUOTE=OG;436112]powered by max will sell you seperate parts to convert the coils you just bought (?)[/QUOTE]
Yes Parts Shop MAX sells dampers and springs separately but...

If you already know the special rates you want before you purchase a set of coilovers & would like to order a higher rate than our in-stock spec, there is no additional charge to special order a set of coilovers custom built to your specifications.  We offer up to 22 kg springs and matched dampers.

i stand corrected.