Flipping Dual Rate Springs

the bodj

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Joined
Apr 4, 2022
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861
Location
Simi Valley, CA
For some background info, I have a beamed/linked/caged crew cab Sonoma with a single coilover and hydro bump on each corner. It really works great, and I'm not planning on adding bypasses for a while, so I'm just thinking of things I can do to help improve. Right now I don't use the slider stops, which is primarily what this post is about.

As far as I know, the standard is to have the heavier spring on the bottom and lighter spring on top. When using the slider stops, your spring rate jumps significantly. I am doing a spring change and will have 300/350 on the front of my 2.5x12" coilovers. I'd like to start using the coil stops to make it a little more progressive to take some harder hits. My worry is that the jump to a 350# spring rate from 160ish# rate would be huge and upset the vehicle. If I can make it work, it'll engage the coil stop slightly before engaging the bumps. Has anyone messed around with swapping the springs so the heavier is on top, and the rate jumps to the lighter spring rate? Are the spring rates close enough that I won't feel a difference? Am I over thinking this?
 
For some background info, I have a beamed/linked/caged crew cab Sonoma with a single coilover and hydro bump on each corner. It really works great, and I'm not planning on adding bypasses for a while, so I'm just thinking of things I can do to help improve. Right now I don't use the slider stops, which is primarily what this post is about.

As far as I know, the standard is to have the heavier spring on the bottom and lighter spring on top. When using the slider stops, your spring rate jumps significantly. I am doing a spring change and will have 300/350 on the front of my 2.5x12" coilovers. I'd like to start using the coil stops to make it a little more progressive to take some harder hits. My worry is that the jump to a 350# spring rate from 160ish# rate would be huge and upset the vehicle. If I can make it work, it'll engage the coil stop slightly before engaging the bumps. Has anyone messed around with swapping the springs so the heavier is on top, and the rate jumps to the lighter spring rate? Are the spring rates close enough that I won't feel a difference? Am I over thinking this?
ADS can probably answer with some maths but here is what I did.

Longer main Spring and shorter secondary. 8" - 350 / 16" -400. = 187lb combined. I was running a 150lb tender spring for a while but I wanted to have the combined rate (187) when the truck was at ride height for the first few inches of travel.

1674857270608.png
When I went with a 350/400 spring setup it was to have some preload on the combined rate so for the few few inches of wheel travel I was running a combined 187lb rate. My goal was to help with the chatter bumps. Was it successful I'm not 100% sure haha.

But I can attest that the truck typically rides on it's main spring of 400lbs when in the dirt. There is no harshness to it when the main spring is engaged. Both setup's were similar in ride quality since the main spring stayed consistent at 400lbs.
 
I feel for optimal performance on a dual rate is to get as long as possible bottom spring so a 16" or 18" in rate you need and short top spring. Then your dual rate stop could be set at same time as bumps engagement to help with bottoming out. Just gotta make sure rebound is right so it doesn't do anything weird once off bumpstops. I'm not shock tuner so gonna pay to have someone tube my truck and get spring rates correct to get optimal performance out of the truck.
 
For some background info, I have a beamed/linked/caged crew cab Sonoma with a single coilover and hydro bump on each corner. It really works great, and I'm not planning on adding bypasses for a while, so I'm just thinking of things I can do to help improve. Right now I don't use the slider stops, which is primarily what this post is about.

As far as I know, the standard is to have the heavier spring on the bottom and lighter spring on top. When using the slider stops, your spring rate jumps significantly. I am doing a spring change and will have 300/350 on the front of my 2.5x12" coilovers. I'd like to start using the coil stops to make it a little more progressive to take some harder hits. My worry is that the jump to a 350# spring rate from 160ish# rate would be huge and upset the vehicle. If I can make it work, it'll engage the coil stop slightly before engaging the bumps. Has anyone messed around with swapping the springs so the heavier is on top, and the rate jumps to the lighter spring rate? Are the spring rates close enough that I won't feel a difference? Am I over thinking this?
the jump in rate will not be too much, when they engage is more important, you are over thinking :cool:, we have and do run huge rate splits on many cars with great results, side note if your valving is so "locked up" that you do not use your dual rate (assuming you have a good spring rate) then your leaving a lot of performance un tapped
 
Copy. Nope, I'm definitely using all she's got. I just haven't messed with the coil stops yet.
the general goal is to run them as high as possible for the combo, sometimes this means they are touching at ride height some times it means they are up to just before the upper coil binds, for your set up i would start about 2" above the slider at ride height and then adjust in .5" increments until it has a negative effect and then back it up to find the sweet spot
 
the general goal is to run them as high as possible for the combo, sometimes this means they are touching at ride height some times it means they are up to just before the upper coil binds, for your set up i would start about 2" above the slider at ride height and then adjust in .5" increments until it has a negative effect and then back it up to find the sweet spot
Ok cool! I'll give it a go and see how it does.
 
Copy. Nope, I'm definitely using all she's got. I just haven't messed with the coil stops yet.
also a pro tip if your running the crowned brand there is an o-ring that lives between each cross over nut make sure you don't try and run the nut over the o-ring or you will be cussing a lot. Personally i remove the o-ring
 
the springs primary function is to hold the vehicle up, valving controls the ride, and at the end you can manipulate spring force to get the vehicle to do things you want it to do. additionally you want more than a 50# split in your rates, 100-150# is the range you want.

plenty of broncos running around with a single coil over no problem. you should be focusing on valving
 
the springs primary function is to hold the vehicle up, valving controls the ride, and at the end you can manipulate spring force to get the vehicle to do things you want it to do. additionally you want more than a 50# split in your rates, 100-150# is the range you want.

plenty of broncos running around with a single coil over no problem. you should be focusing on valving

Idk man, I’m quite happy with my valving. The truck does quite well, and I’m not displeased with it in the least bit. Just trying to get a little more resistance at bump is all.

What is to be gained by having a larger spread in spring rates?
 
your spring rate selections actually generates lower forces that and 150# split which gives you that additional support deep in the travel you are looking for. how much bleed do you have?

1675450657876.png
 
2/3 bleeds open. Valving is pretty spot on aside from speeding up rebound a hair. Mainly looking for increased bottoming resistance on individual big hits. I'm not necessarily trying to make it faster. It's extremely comfortable riding and handles great up to 55 through some heavy stuff. Once I get my ride height up a bit with my new springs I won't be hitting bumps nearly as much (I'll also have bumps in that actually work finally). Just looking for a little more bottoming resistance if I jump or hit a big single object. It's not bad right now, but could be better. I honestly love how it is right now. Kevin at Dialed Shock Prep got me set up with the valving.
 
Kevin at Dialed Shock Prep got me set up with the valving.
you need to be talking to Kevin.

nothing worse than someone seeking internet advice on a setup you did, because there are A TON of ways to setup suspension but its a complete system so his valving is going to work well with the way he does spring setup. its just like a diet/trainer/etc follow their guidance until the results are not what you want, when they cant get you out of the plateau then seek other opinions.
 
I'm not a customer of his, he just helped out with a base tune and I'm not gonna be an ask-hole. But thanks for being awesome.

giphy.webp
 
I'm not a customer of his, he just helped out with a base tune and I'm not gonna be an ask-hole. But thanks for being awesome.

well then thats a different discussion.

a 150# split and plugging a bleed would be a good start to get some more bottom out resistance will minimal impact on ride quality.
 
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