Do springs and shocks need to be matched to perform properly?

[jjvw]

Mr Blaine, I know its frustrating for you, but please continue to contribute to these types of threads. Some of us just have to figure these things out on our own, but your knowledge and insight is helpful. Even if it sounds like we are disagreeing, I think most of us still value your input and use it to help us figure out what is happening.

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Having seen these threads multiple times over the years, as well as having been on both sides, they all play out the same. Apples get compared to oranges, key details and nuances get glossed over. The cats get out of the corral and keep knocking over unrelated dominoes that must get picked up before the cats can be rounded back up. The same explanations trying to help us understand get repeated over and over and over.

Meanwhile, a guy who has actually gone through the efforts to prove and disprove these assertions and beliefs is continually questioned and dismissed.

 

[jjvw]

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Just trying to get across that the statement 'spring rate does nothing to ride characteristic' isn't true.

It can be seen as true when we are working with TJ's and off the shelf springs at a given height, however.

This means that are at least two people here who regularly set up coilovers on Tjs that are doing it wrong.

 

[Daz7]

This means that are at least two people here who regularly set up coilovers on Tjs that are doing it wrong.

No, I don't think they are. In this application what they are doing works.

It's more the blanket statements that I and others look at and go. No, that's not quite right.

There's also an internet mindset that suggests every spring change needs a shock re-valving, that's not correct either.

 

[jjvw]

No, I don't think they are. In this application what they are doing works.

It's more the blanket statements that I and others look at and go. No, that's not quite right.

There's also an internet mindset that suggests every spring change needs a shock re-valving, that's not correct either.

At the risk of sounding harsh, do you see where your blanket statements help perpetuate that internet mindset?

 

[jjvw]

Maybe this will make things worse. Here are estimated lift height calculations for several off the shelf TJ coil springs. One list is for a heavier TJ than the other. The coils are sorted and grouped by lift heights. This allows us to compare the rates and lengths of similar lift heights.

One interesting thing that I saw while putting this together is that with the lighter and heavier rigs, some of these coils flip flop positions in the list order of lift heights. OME941 and BDS 2" for example. I point this out to suggest that focusing on just the rate is to ignore other important aspects of the coil spring. And that comparing one Jeep to another isn't as easy as we would like it to be.

 

[Daz7]

At the risk of sounding harsh, do you see where your blanket statements help perpetuate that internet mindset?

With due respect, I haven't made any blanket statements. Rather draw upon my own experience with suspension setup in both racecars and 4x4's and suggest that the blanket statements aren't entirely correct.

But hey, what would I know. Continue on chaps

 

[Gollywomper]

With due respect, I haven't made any blanket statements. Rather draw upon my own experience with suspension setup in both racecars and 4x4's and suggest that the blanket statements aren't entirely correct.

But hey, what would I know. Continue on chaps

I would have to reread this thread, but I believe everyone was referring to TJ springs and minimal or nonexistent effect in ride quality. I’m not sure anyone implied that springs cannot change the ride on other vehicles.
The consensus, based on TJ’s and my own experience, I just swapped springs, is that the rate changes on specific lift height springs does not change ride characteristics enough to really feel or matter. There are a lot of people come on the forums blaming springs, in a TJ, for bad a ride. When In reality it is shocks and or poorly setup suspension that causes it. That is where the blanket statement of springs not causing a poor ride comes from. If there was a spring on a TJ that did cause a very bad ride the forums would know about it.

 

[ftwhite3]

I can say that from setting up my son's Suburu WRX (strut/coilover) and my TJ (spring&shock) and Silverado (coilover), almost none of that knowledge translated well or directly. Is it being suggested that changing spring rates on a coilover, and strut, and a plain spring are the same thing or have the same results? Seems wrong from my experience.

 

[dudehitt]

Maybe this will make things worse. Here are estimated lift height calculations for several off the shelf TJ coil springs. One list is for a heavier TJ than the other. The coils are sorted and grouped by lift heights. This allows us to compare the rates and lengths of similar lift heights.

View attachment 93852

View attachment 93853

One interesting thing that I saw while putting this together is that with the lighter and heavier rigs, some of these coils flip flop positions in the list order of lift heights. OME941 and BDS 2" for example. I point this out to suggest that focusing on just the rate is to ignore other important aspects of the coil spring. And that comparing one Jeep to another isn't as easy as we would like it to be.

Did you put that together? That's a lot of data. The why on the flip flop is pretty simple. There is a big stiffness difference in those 2 springs and that 100 lbs. per corner is pretty significant. About 1/2" on one, almost 3/4" on the other. They were even at the lighter weight. That spreadsheet just subtracts the stock height from the uncompressed length-force/rate to get lift. That's how you do it, but there are no other factors taken into account as far as i can tell without a pencil and that ain't happening.

I do like the data though. Now i need to weigh my corners.

 

[jjvw]

Did you put that together? That's a lot of data. The why on the flip flop is pretty simple. There is a big stiffness difference in those 2 springs and that 100 lbs. per corner is pretty significant. About 1/2" on one, almost 3/4" on the other. They were even at the lighter weight. That spreadsheet just subtracts the stock height from the uncompressed length-force/rate to get lift. That's how you do it, but there are no other factors taken into account as far as i can tell without a pencil and that ain't happening.

I do like the data though. Now i need to weigh my corners.

This is data I have collected over the years. I built the spread sheet to estimate lift heights, travels and several other things. I have a shock version as well. The heavy jeep example is mine. The lighter is an estimate if I were to replace my enormous rear bumper and lighten up the front a bit.

 

[jjvw]

I think percentage of change is a better way to describe rate change. I saw a couple post where 160 lbs spring were mentioned. I tried to find other rear sprngs, but most don't show rates online. Clayton listed some 225 lbs spring which is 40% stiffer than the 160 lbs springs mentioned. Though not normal, the rates can vary more than just a little different.

If you look at my chart, the Clayton isn't that different than the other ~4" coils. And there isn't a 160lb in that group,

 

[Brianj5600]

If you look at my chart, the Clayton isn't that different than the other ~4" coils. And there isn't a 160lb in that group,

I was refering to these posts. Are you using the springs in the post below?

The OME 'heavy' rear spring is listed at 160lbs/in
They are one of the few that make springs in multiple rates for vehicles. Most are a generic somewhere close that works well.

The OME "heavy" is 160lb; 14.96" free; 2.59" lift (on mine).

 

[jjvw]

I was refering to these posts. Are you using the springs in the post below?

At one point in time I did. I have used several sets of coils on mine.

 

[Brianj5600]

What f/r coils are on it now? Why the change?

 

[jjvw]

What f/r coils are on it now?

Currie 4" with LJ rears.