What is the best riding and performing lift kit for my 2001 TJ?

[Goatman]

Has absolutely nothing I want anything to be. A higher weight spring, all other things being equal will deflect (move) less than a softer rated spring. That is a fact. Irregardless of who makes the spring. Has nothing to do with OME making 2 different spring rates compress the exact same. Because one Jeep weighs more or less than another. The softer spring will settle to the height that the weight of the Jeep makes it settle to. Add 50 lbs of winch or bumper and the two rates will deflect differently. It is absurd to expect two different springs to compress equally regardless of the weight placed on them. There are TJs that easily weigh 1,000 lbs more than other TJs.
The purpose of the spring rate isn't to compress the same as another spring rate. It is the exact opposite.
Again, the shock is to control the movement of the spring. Not the other way around. And having your "proof" consisting of 1 person installing 1 spring set and stating it rides good makes as much sense as dissolving the police department to improve law enforcement. (Cheap shot, I know, but not wrong.)

 

[jjvw]

I think you just described the fact that the springs are used to set the ride height.

If this is not the case, then you are obligated to explain to us how one selects an OME or any other spring in such a way that both establishes the desired ride height AND influences the ride quality at the same time. You get to explain with specific numbers and specific springs how to make the ride stiffer or softer using only springs.

 

[WallyWest]

I feel like you guys are arguing the same point from different sides. LoL

 

[jjvw]

I feel like you guys are arguing the same point from different sides. LoL

I am arguing one thing and one thing only. Springs are used to set the ride height. Nothing more.

 

[thomat65]

I am arguing one thing and one thing only. Springs are used to set the ride height. Nothing more.

If I can stick my face in this fire, would you also agree that a softer and longer spring would give the same ride height as a firmer shorter spring?

Assuming you would then I don't think you're disagreeing with @Goatman.

Just trying to reconcile the different viewpoints

I see one side saying "springs control ride height" and another side saying "springs affect ride quality". I think both are right.

To further attempt to reconcile these two sides, follow me down the rabbit hole.

In my imaginary world I replaced my Jeep's OEM (not OME ) springs with the highest spring rate material I know of--cinder blocks. I used a concrete saw to set the ride height just the way I like and its stance looked great. In my excitement and eagerness to hit the trail I flung open the door and leapt into the driver's seat. As I backed out the tires ran over the crack between by garage floor and the paved driveway "Oof! I felt that!" I ran over a squirrel on the way to the trail "Oof! I felt that!" I felt every pebble under the tires as my brains rattled out. By the time I got to the trail I was so exhausted from the rough ride I had to turn around and go back home.

Obviously the stiff "springs" gave a poor ride.

Since I have friends who went to college I knew the way to fix this. I replaced my "springs" with the softest spring rate material I know of--air. It's hard for me to verbally explain what I did next but imagine the effect of the Jeep sitting on a 1 square inch piston in a mile long cylinder filled with compressed air. That's effectively what I did with some clever plumbing. I then spent the next three months running my air compressor to get the ride height I needed. But it looked great! You could barely see the plumbing poking out everywhere! In my excitement and eagerness to hit the trail I flung open the door and leapt into the driver's seat and... the Jeep bottomed out. The "spring" "height" was tall enough to get a good ride height on my Jeep, but the "spring" rate was too soft for the Jeep + the weight of me.

Obviously the soft "springs" were useless for what I wanted.

At that point I realized both of these scenarios had a problem with the springs. I knew I wouldn't be able to make cinder blocks compliant even by adding shocks, and I knew I wouldn't be able to keep my floating Jeep from bottoming out. And so I put my OEM springs back in and next turned to focus on the shocks.

Sitting on my shelf were a full set of Thomat65©™® shocks. Why yes I did make them all by myself, thanks for noticing how clever I am! You'll also notice that instead of letting the hydraulic fluid leak from the bottom half of the shock through the plunger into the top half of the shock (what a silly design! those fools!) I plugged those pesky holes and valves so it's guaranteed that absolutely no hydraulic fluid will ever escape the bottom half of the shock. They were foolproof! After slapping those bad boys on I flung open the door and leapt into the driver's seat and... to my satisfaction I noticed the Jeep didn't budge at all. Not even one little jounce. Down the driveway I went. As I backed off my inclined driveway and turned onto the road I noticed that as I turned and traveled over that angle where the incline met the flat road two tires at opposite corners were planted but the other two were suspended in the air. Yup, these shocks weren't letting the wheels travel at all! Who needs articulation when you have shocks like these! Being very proud of myself I continued down the road. I ran over that same squirrel again "Oof! I felt that!" Wait a minute... that can't be right... I had the most clever shocks in the world! But I ran over a few pebbles and sure enough "Oof! I felt those!" A few minutes later I had to turn around because my brains had rattled out of my skull again.

I called up my smart friends and in unison they said "obviously it's your shocks!" Dismayed yet knowing they had a larger vocabulary than me I decided maybe my clever shocks just needed some time to be broken in. But that had to happen later because I wanted to hit the trail now. So I did the next best thing I knew--I removed the shocks from my Jeep. It only took an hour and the Jeep still sat at the same exact beautiful ride height as before even though it had no shocks whatsoever. I was so excited because I knew this time it was going to work! I flung open the door and leapt into the driver's seat and... the Jeep rebounded so bad it flung me right out the other side! Flying up through the air and landing hard on the concrete floor head first I woke up and realized it was all just a dream.

I think both sides would agree that there's a happy place in there somewhere. A happy place where the springs will comfortably support your ride at a good height over all the desired load ranges, and where the shocks will happily detune whatever is under the tires from your skull.

 

[jjvw]

If I can stick my face in this fire, would you also agree that a softer and longer spring would give the same ride height as a firmer shorter spring?

Assuming you would then I don't think you're disagreeing with @Goatman.

Just trying to reconcile the different viewpoints

I see one side saying "springs control ride height" and another side saying "springs affect ride quality". I think both are right.

To further attempt to reconcile these two sides, follow me down the rabbit hole.

In my imaginary world I replaced my Jeep's OEM (not OME ) springs with the highest spring rate material I know of--cinder blocks. I used a concrete saw to set the ride height just the way I like and its stance looked great. In my excitement and eagerness to hit the trail I flung open the door and leapt into the driver's seat. As I backed out the tires ran over the crack between by garage floor and the paved driveway "Oof! I felt that!" I ran over a squirrel on the way to the trail "Oof! I felt that!" I felt every pebble under the tires as my brains rattled out. By the time I got to the trail I was so exhausted from the rough ride I had to turn around and go back home.

Obviously the stiff "springs" gave a poor ride.

Since I have friends who went to college I knew the way to fix this. I replaced my "springs" with the softest spring rate material I know of--air. It's hard for me to verbally explain what I did next but imagine the effect of the Jeep sitting on a 1 square inch piston in a mile long cylinder filled with compressed air. That's effectively what I did with some clever plumbing. I then spent the next three months running my air compressor to get the ride height I needed. But it looked great! You could barely see the plumbing poking out everywhere! In my excitement and eagerness to hit the trail I flung open the door and leapt into the driver's seat and... the Jeep bottomed out. The "spring" "height" was tall enough to get a good ride height on my Jeep, but the "spring" rate was too soft for the Jeep + the weight of me.

Obviously the soft "springs" were useless for what I wanted.

At that point I realized both of these scenarios had a problem with the springs. I knew I wouldn't be able to make cinder blocks compliant even by adding shocks, and I knew I wouldn't be able to keep my floating Jeep from bottoming out. And so I put my OEM springs back in and next turned to focus on the shocks.

Sitting on my shelf were a full set of Thomat65©™® shocks. Why yes I did make them all by myself, thanks for noticing how clever I am! You'll also notice that instead of letting the hydraulic fluid leak from the bottom half of the shock through the plunger into the top half of the shock (what a silly design! those fools!) I plugged those pesky holes and valves so it's guaranteed that absolutely no hydraulic fluid will ever escape the bottom half of the shock. They were foolproof! After slapping those bad boys on I flung open the door and leapt into the driver's seat and... to my satisfaction I noticed the Jeep didn't budge at all. Not even one little jounce. Down the driveway I went. As I backed off my inclined driveway and turned onto the road I noticed that as I turned and traveled over that angle where the incline met the flat road two tires at opposite corners were planted but the other two were suspended in the air. Yup, these shocks weren't letting the wheels travel at all! Who needs articulation when you have shocks like these! Being very proud of myself I continued down the road. I ran over that same squirrel again "Oof! I felt that!" Wait a minute... that can't be right... I had the most clever shocks in the world! But I ran over a few pebbles and sure enough "Oof! I felt those!" A few minutes later I had to turn around because my brains had rattled out of my skull again.

I called up my smart friends and in unison they said "obviously it's your shocks!" Dismayed yet knowing they had a larger vocabulary than me I decided maybe my clever shocks just needed some time to be broken in. But that had to happen later because I wanted to hit the trail now. So I did the next best thing I knew--I removed the shocks from my Jeep. It only took an hour and the Jeep still sat at the same exact beautiful ride height as before even though it had no shocks whatsoever. I was so excited because I knew this time it was going to work! I flung open the door and leapt into the driver's seat and... the Jeep rebounded so bad it flung me right out the other side! Flying up through the air and landing hard on the concrete floor head first I woke up and realized it was all just a dream.

I think both sides would agree that there's a happy place in there somewhere. A happy place where the springs will comfortably support your ride at a good height over all the desired load ranges, and where the shocks will happily detune whatever is under the tires from your skull.

I didn't read all that. Yes, you can absolutely have two springs with different rates and lengths that add up to the same ride height on the same Jeep.

In addition to offering the same ride height, these two springs will also need to have a sufficient free length and minimal solid height to support a typical properly sized shock. Those requirements wipe out the extreme examples of a block of cast iron or a Slinky. Meaning these hypothetical two springs are both reasonable, plausible and practical for our application.

The variance between these two hypothetical springs will not matter as far as discernable differences in ride quality is concerned.

You do not get to use a cinder block as a way to prove otherwise because no reasonable person would do that.

 

[thomat65]

I didn't read all that.

No worries. It was more fun writing than it probably is for anyone else to read

You do not get to use a cinder block as a way to prove otherwise because no reasonable person would do that.

If I'm understanding you correctly, you're saying the cinder block isn't a good example because it's unreasonable, correct? Unreasonable in that it has neither the free length nor the minimal solid height (it doesn't allow full shock travel). Sounds reasonable to me.

The variance between these two hypothetical springs will not matter as far as discernable differences in ride quality is concerned.

That sounds reasonable to me inasmuch as the difference is indiscernible.

In order to posit a reasonable counterexample I'd need more experience and knowledge than I have. I'd have to say "spring X is Y% longer and softer than spring Z, both springs allow full travel, and I can tell from experience that X is softer". Lacking that experience and knowledge I'll now exit stage left

 

[KimsJeep]

I went through the same arguing with myself over the springs. Ultimately when I discovered that the difference in spring rate between the light and heavy duty OMEs is only 20 pounds I just got the HDs.

If there's any possible chance you may put more armor, bumpers, winch, etc... then get the HDs for sure. And if not, you'll get a 1/2 inch or so more lift from the HD. And I can't imagine 20 pounds difference in spring rate will affect the ride quality to any significant degree.

When I bought my OME springs from someone on this site, I was a little worried about my ride quality because they were the HD springs. I have no hard top and stock bumper and spare carrier in the back and I have a stock bumper with a bigger guard and winch on the front. I was mainly worried about the back being light and having HD springs. The price was right though and I got them and put them on. I was really surprised with the ride quality afterward. It was actually better then before and I had stock springs with RanchoX shocks. Even my hubby commented on how nice the ride was after putting on the OME HD springs. I'm a happy camper.

 

[jjvw]

No worries. It was more fun writing than it probably is for anyone else to read



If I'm understanding you correctly, you're saying the cinder block isn't a good example because it's unreasonable, correct? Unreasonable in that it has neither the free length nor the minimal solid height (it doesn't allow full shock travel). Sounds reasonable to me.



That sounds reasonable to me inasmuch as the difference is indiscernible.

In order to posit a reasonable counterexample I'd need more experience and knowledge than I have. I'd have to say "spring X is Y% longer and softer than spring Z, both springs allow full travel, and I can tell from experience that X is softer". Lacking that experience and knowledge I'll now exit stage left

My examples of an iron block and a Slinky that both provide the same ride height are interesting in that they show the uselessness of trying to use extreme examples that no reasonable person would ever do. Both result in the very same disaster of a ride, even though one has a free length that reaches to the end of the block.

Useful examples need to fit the application. Any one of those examples are supporting the same weight of the Jeep. They can only react to the weight of the Jeep.

 

[WallyWest]

I am arguing one thing and one thing only. Springs are used to set the ride height. Nothing more.

True. Assuming nothing is binding up and limiting travel then yes, your height sitting still is due to spring length and stiffness vs. vehicle weight.

In motion however the shocks, as well as all the other suspension components and body mounts will factor into ride quality. And while you could replace your tall/soft springs with short/stiff ones, or vice versa, and maintain the same ride height your ride quality will be very different.

 

[jjvw]

.... And while you could replace your tall/soft springs with short/stiff ones, or vice versa, and maintain the same ride height your ride quality will be very different.

Read my criteria above. These hypothetical springs need to plausible and usable.

If you are going make that claim, you need to provide some numbers.

 

[bobthetj03]

True. Assuming nothing is binding up and limiting travel then yes, your height sitting still is due to spring length and stiffness vs. vehicle weight.

In motion however the shocks, as well as all the other suspension components and body mounts will factor into ride quality. And while you could replace your tall/soft springs with short/stiff ones, or vice versa, and maintain the same ride height your ride quality will be very different.

The best way I can think of to test this, and it could probably be done with just the rear springs, is remove the rear shocks and run just the springs. First try a 140 inlb. set, then try a 200 inlb. set, but having the proper length springs to keep the jeep at the same height. Notice any difference in ride quality between the two?

 

[WallyWest]

Read my criteria above. These hypothetical springs need to plausible and usable.

If you are going make that claim, you need to provide some numbers.

That claim is based on simple physics.

Are you aware that spring rate is variable? As it compresses the effective rate increases, until it reaches equilibrium with the force pushing down on it. A spring with a higher base rating will move less than a softer spring, resulting in a harsher ride, all other things being equal.

 

[jjvw]

I have played the spring game. This is something I have done. Any difference between soft and hard springs and provide very similar ride heights and corrected with spacers is so slight that I don't know if it was real or not. This is my direct experience.

My rear Fox shocks have 8 point compression adjustors. The softest setting is like riding on a cloud, but body roll is pronounced during city street turns or long sweeping highways. Cranking them up to 8 changes everything. Body roll nearly disappears in every situation. Highway travel is nearly as comfortable and cloud-like, but slower city streets have a very pronounced jittery feeling. Off road performance actually improved with the increased control of the articulating axles and dramatically reduced body roll.

Changing my shocks between their softest and stiffest settings is simply dramatic and has no comparison to anything I have done with springs. It is exceedingly clear to me that springs have one job and that is to establish the ride height. Nothing else. Any efforts to change the ride must be placed on the shocks.

 

[bobthetj03]

That claim is based on simple physics.

Are you aware that spring rate is variable? As it compresses the effective rate increases, until it reaches equilibrium with the force pushing down on it. A spring with a higher base rating will move less than a softer spring, resulting in a harsher ride, all other things being equal.

Are you saying that all spring rates are variable? What about a constant rate spring, like OME's, or progressive rate springs, or dual rate, or triple rate?

 

[jjvw]

Are you saying that all spring rates are variable? What about a constant rate spring, like OME's, or progressive rate springs, or dual rate, or triple rate?

Years ago, I measured the rate of one of my sets of OME coils. The graph was quite linear to the extent today I could measure it with a floor jack. The Currie 3" may have been slightly progressive, but not very much.

 

[WallyWest]

I specifically said "all other things being equal". Drastically changing shock valving and/or travel can obviously have an effect on ride performance. So can changing the spring rate.

Sorry but that's the way it is.

 

[thomat65]

I specifically said "all other things being equal". Drastically changing shock valving and/or travel can obviously have an effect on ride performance. So can changing the spring rate.

Sorry but that's the way it is.

I think people are getting hung up on you saying the spring rate changes as a (normal) spring compresses. My understanding is the force does go up in response to the change in length, but only because the spring rate is the (constant in what I'm calling a normal spring) ratio between force and distance. I get what you mean and I think what you mean is correct. Everyone feel free to correct me.

 

[jjvw]

I specifically said "all other things being equal". Drastically changing shock valving and/or travel can obviously have an effect on ride performance. So can changing the spring rate.

Sorry but that's the way it is.

Tell us how to tune the ride through the springs. I ask this question over and over again, but no one ever shares their secret knowledge on how to do this.

We even had a coilover tuner here recently whose cars compete in and have podium finishes at KOH. He doesn't even try to tune the ride through the springs.

Maybe you can help him out.

 

[WallyWest]

Are you saying that all spring rates are variable? What about a constant rate spring, like OME's, or progressive rate springs, or dual rate, or triple rate?

Yes, all spring rates are variable. That's how a spring works. As you compress it resistance increases. Stand on your bumper, notice any movement? That's because your added weight compressed the spring a bit, and it's resistance increases with the compression, which is why it only moves a little bit.

Progressive springs have different windings to fine tune exactly how resistance changes over their operating range. Essentially an attempt at two springs in one. It works, but it's more critical to make sure your vehicle weight is correct for the spring.