What is the best riding and performing lift kit for my 2001 TJ?
- Thread starter 01saharatj
- Start date
I feel it's better for you explain to everyone why you can't tune a coil-over with springs when the worlds most respected spring maker states in black and white that you can:
C- Dual- or Multiple-Rate ERO Systems use proprietary super-high tensile alloy and manufactured to the industry leading tolerances. These systems use a series of springs to achieve both maximum travel and tune-ability. With thousands of different spring configurations available, the exact characteristics can be achieved.
D - Dual- or Multiple-Rate ERO Systems use proprietary super-high tensile alloy and manufactured to the industry leading tolerances. These systems use a series of springs to achieve both maximum travel and tune-ability. With thousands of different spring configurations available, the exact characteristics can be achieved.
No, my question to you was to tell everyone why you can't tune a coil-over with springs.
You constantly state that you want to be shown how you can tune using springs. As we're now onto coil-overs here is a manufacturer that provides that option for the off-road user.
...onto something more positive. Coil-overs suitable for a 4" lift TJ user, now that's an exciting prospect.
Those guys over at Eibach even claim that spring choice can affect oversteer/understeer, body roll, squat, and dive.
No question those things can also be tuned for by shock tuning and geometry changes in a vehicle. But I don't see how you can say that springs are irrelevant. The amount of tunability based on 'over the counter' coils might be minimal, but its still there.
No question those things can also be tuned for by shock tuning and geometry changes in a vehicle. But I don't see how you can say that springs are irrelevant. The amount of tunability based on 'over the counter' coils might be minimal, but its still there.
Not one iota of that applies once you get past about 3" of travel in the shock. Ya'll can't do what you are saying is possible unless you want to run about a 10" tender spring. No one who sets up shocks does that, no one.
We know a guy who does that fairly often. Might want to get his thoughts on the matter.
4" lifted TJ with coil overs and stock width axles? You mean like this one I did?
With all of your knowledge, understanding and resources in mind, what role did the springs play when you tuned the coilovers?
Zero for tuning. We weighed the rig's sprung weight with a pair of springs and gave that weight to our tuner to get back a set of springs that would give us the full travel of the shock without the use of a tender spring. We also like about 1-1.5" of preload to keep all the shock bits in place. We want the lightest spring possible that will give us the ride height and travel without going into coil bind or coming loose at full extension.
Once you settle on those parameters, the range of options is very narrow. For a 12" shock, we typically wind up with a 12" over a 14" spring to stop the use of a tender since tenders are not that good. For a 14" shock, we typically wind up with a 14" over a 16" spring for the same reasons.
When the rig is at the design ride height, we discuss the amount of uptravel, shock angle (if dramatically different than typical recommended practices) and rear half weight. The front half is generally very similar. The back half is where we vary a bunch in how the shocks get tuned. We never pay any attention to springs after we get them to do their job which is to hold the rig at our design height and cover full extension and full compression.
In fact, two things are true. Our tuner has yet to miss a spring selection for us. We have never swapped out a spring to change ride quality characteristics. Any change in ride quality we are after is done with the shock tuning.
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Very nice TJ, Sounds like you have a good guy doing coil-over setup.
We're limited here with regard to modifications to OEM mounts. To propose anything like this it would be a lengthy and costly engineering pathway to maintain road use status. It's very annoying and constrains whats possible.
We're limited here with regard to modifications to OEM mounts. To propose anything like this it would be a lengthy and costly engineering pathway to maintain road use status. It's very annoying and constrains whats possible.
I sometimes wonder if we are arguing over the meaning of the word tuning. Because to me, that first sentence sounds like you did the initial tuning with the springs. Then you did the fine tuning with the shock.
You are obviously very methodical about getting the proper spring setup before you do any shock tuning. Your diligence in selecting the proper springs right from the start seems very inconsistent with stating that springs don't make a difference. I obviously don't have your knowledge and experience, so I am struggling to put together why it is so important to use the lightest spring possible, when the spring rate doesn't matter.
Eitherway, now I am wondering if I made a mistake ordering a set of 3" JKS springs instead of Savvy this morning. But my research indicated the Savvy are very light and I didn't think the Savvy would hold the weight of my LJ at the intended height. So maybe I am going about it in the same manner that you do after all. But I'm still struggling with how rates don't matter, but so much effort is put into finding the proper springs before any tuning is done.
Thanks for monitoring this thread. Even if I disagree or simply don't understand what you are saying, I appreciate your participation.
We don't tune springs since they are un-tunable. They have one job, to hold the rig up at the height we desire, that's it.
If you don't use the lightest spring possible, then you are trying to get the spring to do the job of the shock and that doesn't work. Spring rate only matters to get the rig at the correct ride height, nothing more.
Ya'll keep trying to make the springs do something they aren't cut out to do and it shows in every thing ya'll post.
This may help with the disconnect. Not once have I ever been asked what spring rate I want. Not once have I ever said I want XX for a spring rate. All I want the springs to do is hold the rig up at design height. That is not any part of the tuning except to give the shock a chance to do its job.
I probably shouldn't post in this thread, it should probably die. But I'm a glutton for punishment sometimes. I think to setting up the fork in my mountain bike. It's an air spring, so I have, in effect, an infinitely variable set of springs I can try for tuning. But I don't. The way you set up a fork is to put enough air pressure in it to hold your weight at 20-30% sag. Then you forget about it. If you're bottoming out, you add tokens (essentially an air bump) or increase the damping. If it's too stiff, you decrease the damping. If it's springing back? Increase the rebound damping. I twiddled those dials a lot when I was learning the effects of each of them. I never once changed my spring (air pressure). Yet, I could make a drastic difference in the feel of the bike and my enjoyment of the ride, just by spinning a dial.
If I had tried to time my ride through air pressure, I would have thrown one of my other setup criteria off (namely sag). For instance, If I had added air pressure (stiffer spring) to control bottoming out, my sag would be less, and it would have a detrimental effect on the handling.
If you are supporting the weight of the vehicle at the proper ride height, and the spring can not fall out or coil bind within the designed axle travel, you have gotten the right spring. No need to do anything further with springs.
From that point on, you will be tuning your ride with damping.
If I had tried to time my ride through air pressure, I would have thrown one of my other setup criteria off (namely sag). For instance, If I had added air pressure (stiffer spring) to control bottoming out, my sag would be less, and it would have a detrimental effect on the handling.
If you are supporting the weight of the vehicle at the proper ride height, and the spring can not fall out or coil bind within the designed axle travel, you have gotten the right spring. No need to do anything further with springs.
From that point on, you will be tuning your ride with damping.
It is that simple. I think this would be a lot easier if folks have played with shock tuning and adjustable damping reservoirs on shocks. You can go from making it ride very soft to making it ride like an empty dump truck and never touch or care about what the spring rate is.
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Mine has 8 point compression adjustors on the rear shocks. The difference between 1 and 8 is very dramatic.
jesseshoots
TJ Enthusiast
Shocks react to velocity based inputs. Springs react to displacement based inputs.
The shock does all the work to control how fast/slow the spring will load and unload. This is what determines ride quality, not the reactive force of the spring.
It is truly that simple.
The shock does all the work to control how fast/slow the spring will load and unload. This is what determines ride quality, not the reactive force of the spring.
It is truly that simple.