Coilovers shocks spring configuration

[Nice Little Jeep]

 

These are the basic spring rates for King coil-overs 12” shocks.

 

These are the basic spring rates for King coil-overs 14” shocks.

 

My current configuration:

front springs, SPR25-12-250 top/bottom drive/passenger side.

rear springs, SPR25-12-200 top, SPR25-12-250 bottom 

 

EVO started offering an increased spring rate for JK Jeep with full accessories. “EVO MFG Bolt on Coil-over owners running a fully accessorized Jeep JK/JKU and/or looking for additional lift the EVO Heavy Duty Coil-over springs are here to help you achieve that.” I don’t know what the spring rates that EVO is offering.

 

Best description I can find on EVO spring kit. 

https://www.carid.com/evo-manufacturing/hd-coilover-coil-springs.html#features

 

so with that being said, I’ve looked into increasing my springs and I’m looking for thoughts:

 

Future configuration:

 

front springs, SPR25-12-250 top both sides, SPR-14-300 bottom drive side, SPR-14-350 bottom passenger side.

 

rear springs, SPR25-12-250 top both sides, SPR25-12-300 driver side, SPR-12- 350 passenger side.

 

The increase spring rate on the passenger side helps with the increase weight of the fuel tank, battery and accessories (refrigerator and on my jeep the point load of the spare tire is on the passenger side).

I would like to hear some input and questions.

[KevinG]

I'm a noob at this too so take this with a grain of salt.  Hopefully someone like Redline will see this and chime in.

https://www.crawlpedia.com/coilover_setup.htm.   This is one of the better "idiots guide to coilovers"  it had lots of pictures which is great for me.  

 

Definitely want to start by checking the nitrogen pressure.  If you don't have the set up for that, it's in the link I posted.

 

 

  I was pretty meticulous when I initially set them up, going so far as to load tools, pull the spare and tried to get exactly a half tank of gas in it.   In hindsight it was probably overkill.  I daily mine so there are some days when I have two 100 lb dogs with me, or my daughter, maybe the hardtop, my wife etc.  Full tank of fuel to no fuel.  So many variables.  But here is my set up when I started and pretty much where it sits today.

   In my front I have 250# over 300#.  The passenger side is about 2.5 inches of pre load and the driver's side has 1 inch.  Stop rings are both 1" above the slider.

The back end of my jeep is pretty light as I don't carry a lot of stuff so  have 200# over 250#.  Drivers side pre load is pretty minimal at a half an inch, passenger has about an inch and a quarter.  Stop rings are about a half inch above the slider.  Everything sits pretty level side to side.

[Nice Little Jeep]

Yes, I have JKU with evo long arms, evo bolt on coilovers, UD60s, with 40" tires

[Weebz]

Every rig is going to be different, substantially.   I fought issues in mine with drooling up front (never really did figure it out).   However, spring rates akin to whet Kevin posted sre far more in line with what I would expect to run.  350# rates seem way too high.  

[Nice Little Jeep]

That’s good stuff, going through the calculations process, I’ve come up with the following:

 

front springs, SPR25-12-250 top both sides, SPR-14-300 bottom both sides.

 

note: I’m looking at changing that Bottom front Springs to a 14” so I have adjustment in the transfer ring, right now I have no adjustment.

 

rear springs, SPR25-12-250 top both sides, SPR25-12-300 bottom both sides.

 

what do you think?

[KevinG]

47 minutes ago, Nice Little Jeep said:

Yes, I have JKU with evo long arms, evo bolt on coilovers, UD60s, with 40" tires

 

Yes I am the same.  But that's only half the story.  Like Jeff said, each jeep is different.  I think Alan is still running bolt on coilovers from Evo.  When I bought the HD springs, he got my rear HD's because my back end was quite a bit lighter.  He had an Evo carrier, Evo corners which I think are quite a bit heavier than the Genright stuff I have back there.  

 

I personally would skip the 14" spring on the rear coilovers.    When you load the 12" in to the rear coilover, it's pretty much under load before from the start as opposed to the front where it takes a quarter inch take up the "slack".  I would think once you put a 14" in there, it's going to be pretty much at coil bind.  Do you have pics of how you have it set up now and have you checked to see if the shocks are charged?

[MIOffroadCustoms]

Hopefully Redline can elaborate on this….
 

 The best thing to do is get corner weights front & rear as well as sprung & unsprung. With your typical gear for a trail ride. It is very hard to nail the spring rate as every Jeep/rig/setup is different.  There are calculations that can be done to get close but not perfect. Most fab shops or race shop / programs will have corner scales & can help with this. This is the only true guaranteed way to get the ride quality & shaft showing/ ride height that you require. Once you have the weights you can call Magnitude (USA made & my 1st choice) or PAC or King or Viper Springs and they will tell you exactly what spring rate to run.

I weight every rig that leaves my shop this way & have nailed the spring rate & ride height 1st try every time. 
 

I hope this helps a little. 

[Nice Little Jeep]

[Nice Little Jeep]

18 hours ago, Nice Little Jeep said:

That’s good stuff, going through the calculations process, I’ve come up with the following:

 

front springs, SPR25-12-250 top both sides, SPR-14-300 bottom both sides.

 

note: I’m looking at changing that Bottom front Springs to a 14” so I have adjustment in the transfer ring, right now I have no adjustment.

 

rear springs, SPR25-12-250 top both sides, SPR25-12-300 bottom both sides.

 

what do you think?

I ordered the springs yesterday, the only change I can see making is going with 350lb springs on the bottom and that doesn’t make sense at this point. It’s only money and time, which I don’t have either, so this decision is a perfect scenario for me

[KevinG]

It can be a rabbit hole for sure.

  I think I had asked this before, but did you get a chance to check pressure.  And I'm sure you know this so forgive me if you know this already, but make sure you check it with a nitro kit.  Can't just do it with a pressure gauge.  I ask because when I got mine the pressures where any where from 150 psi to 25.  Have to start with the right pressure or everything else is messed up.

In your pics are you at the ride height you want?  (assuming the pressure in the shock is 150)

 

 

  

[KevinG]

There was another video that I watched at some point that I just found.  I'm sure someone like Redline can shed so much more light on the subject, but this was also good for just getting to know a few basic terms and visualizing things.

 

 

[Nice Little Jeep]

6 hours ago, KevinG said:

It can be a rabbit hole for sure.

  I think I had asked this before, but did you get a chance to check pressure.  And I'm sure you know this so forgive me if you know this already, but make sure you check it with a nitro kit.  Can't just do it with a pressure gauge.  I ask because when I got mine the pressures where any where from 150 psi to 25.  Have to start with the right pressure or everything else is messed up.

In your pics are you at the ride height you want?  (assuming the pressure in the shock is 150)

 

 

  

 

Yes, have the kit. once I install the new Springs I’ll reverse my pressures and start over.

[AJK]

Did you buy King? Eibach is a much better spring.

[Nice Little Jeep]

On 10/21/2022 at 9:02 PM, AJK said:

Did you buy King? Eibach is a much better spring.

Know you tell me , I bought King

[Redline]

SORRY!! I have been a little busy for the past few months and havent had time get on here.  

#1- I generally would never mix rates side to side. That will cause some ride issues that can never really be corrected. With C/Os you can add the extra preload to the passenger side to get the ride hieght pretty leve and then adjust cancel out rings to get the final ride nice. If you run different springs side to side it is always going to have a side kick when engaging the single rate as speed.

#2- Have found personally that 10" over 14" in the front and 10" over 12" in the rear seems to make the best combo for tuneability 

#3- I would not go above a 300lbs rate on any corner of a jk unless it was extremely loaded

#4- In the "ideal" world you have 1-2" of preload at full droop on your springs. That is the measurement of how much you springs combined are compressed and not just how far the preload nut is turned down.

#5- Eibach is a Much better spring. I love Kings and have been friends with Brett for a couple decades, but I choose Eibach over the others because have good experience with them and usually can get them same or next day.

#6- Charge your shocks min 150psi but 200-225 is better if really going to use them

[AJK]

30 minutes ago, Redline said:

SORRY!! I have been a little busy for the past few months and havent had time get on here.  

#1- I generally would never mix rates side to side. That will cause some ride issues that can never really be corrected. With C/Os you can add the extra preload to the passenger side to get the ride hieght pretty leve and then adjust cancel out rings to get the final ride nice. If you run different springs side to side it is always going to have a side kick when engaging the single rate as speed.

#2- Have found personally that 10" over 14" in the front and 10" over 12" in the rear seems to make the best combo for tuneability 

#3- I would not go above a 300lbs rate on any corner of a jk unless it was extremely loaded

#4- In the "ideal" world you have 1-2" of preload at full droop on your springs. That is the measurement of how much you springs combined are compressed and not just how far the preload nut is turned down.

#5- Eibach is a Much better spring. I love Kings and have been friends with Brett for a couple decades, but I choose Eibach over the others because have good experience with them and usually can get them same or next day.

#6- Charge your shocks min 150psi but 200-225 is better if really going to use them

Thanks Devin you experience and knowledge is always welcomed and appreciated.

[Nice Little Jeep]

53 minutes ago, Redline said:

SORRY!! I have been a little busy for the past few months and havent had time get on here.  

#1- I generally would never mix rates side to side. That will cause some ride issues that can never really be corrected. With C/Os you can add the extra preload to the passenger side to get the ride hieght pretty leve and then adjust cancel out rings to get the final ride nice. If you run different springs side to side it is always going to have a side kick when engaging the single rate as speed.

#2- Have found personally that 10" over 14" in the front and 10" over 12" in the rear seems to make the best combo for tuneability 

#3- I would not go above a 300lbs rate on any corner of a jk unless it was extremely loaded

#4- In the "ideal" world you have 1-2" of preload at full droop on your springs. That is the measurement of how much you springs combined are compressed and not just how far the preload nut is turned down.

#5- Eibach is a Much better spring. I love Kings and have been friends with Brett for a couple decades, but I choose Eibach over the others because have good experience with them and usually can get them same or next day.

#6- Charge your shocks min 150psi but 200-225 is better if really going to use them

Thank you, great information,

 

[Nice Little Jeep]

On 10/17/2022 at 5:28 PM, Nice Little Jeep said:

You can see in the picture the difference in the front coilover on preload, and ride height. 1/2” of more ride height with new setup 250/300 bottom spring is 14”, pressure for now 150psi. Looking at driver side.

 

[Nice Little Jeep]

On 10/16/2022 at 9:10 AM, Nice Little Jeep said:

 

These are the basic spring rates for King coil-overs 12” shocks.

 

These are the basic spring rates for King coil-overs 14” shocks.

 

My current configuration:

front springs, SPR25-12-250 top/bottom drive/passenger side.

rear springs, SPR25-12-200 top, SPR25-12-250 bottom 

 

EVO started offering an increased spring rate for JK Jeep with full accessories. “EVO MFG Bolt on Coil-over owners running a fully accessorized Jeep JK/JKU and/or looking for additional lift the EVO Heavy Duty Coil-over springs are here to help you achieve that.” I don’t know what the spring rates that EVO is offering.

 

Best description I can find on EVO spring kit. 

https://www.carid.com/evo-manufacturing/hd-coilover-coil-springs.html#features

 

so with that being said, I’ve looked into increasing my springs and I’m looking for thoughts:

 

Future configuration:

 

front springs, SPR25-12-250 top both sides, SPR-14-300 bottom drive side, SPR-14-350 bottom passenger side.

 

rear springs, SPR25-12-250 top both sides, SPR25-12-300 driver side, SPR-12- 350 passenger side.

 

The increase spring rate on the passenger side helps with the increase weight of the fuel tank, battery and accessories (refrigerator and on my jeep the point load of the spare tire is on the passenger side).

I would like to hear some input and questions.

New configuration:

front springs, SPR25-12-250 top, SPR-14-300  bottom.

 

rear springs, SPR25-12-250 top, SPR25-12-300 bottom.

 

now working on the gas pressures currently running 150psi going to move up to 200 once I take it off-road.

[Redline]

Before I switched to the 60s and had to redo lower mounts, My jeep was pretty happy with 250/275 in the front and 300/250 in the rear. I went with 300 over 250 in the rear because I needed the extra spring for ride height but did not want the extra spring when bottoming. 

Now that I have moved the lower shock mounts I am going to go to 250/250 in the front and 275/250 in the rear most likely because I have zero preload on the driverside and it is a little on the stiff side for me.

[AJK]

Dennis are the coils moving at full droop? Can you move them up and down by hand? The pictures looks like you have zero preload in two of the shocks and that's not good or is a result of being sprung to heavy.

[Nice Little Jeep]

9 minutes ago, AJK said:

Dennis are the coils moving at full droop? Can you move them up and down by hand? The pictures looks like you have zero preload in two of the shocks and that's not good or is a result of being sprung to heavy.

The front springs are 12/14 (top/bottom) at full droop can turn the springs, no preload. The preload is on the passenger side only to level the Jeep.

 

note: at full droop no preload the springs don’t move up and down, I can only turn them.

 

rear has 12/12 at full droop I can turn but not move them freely, again The preload is on the passenger side only to level the Jeep. 
 

I’ve been running shock bumps from the original setup upgrade. That’s why I’m setting up my springs differently now. I’ve been riding on those shock bumps too much in the initial setup.

 

With the changes right now, I’m not running on the shock bumps and it feels a lot more solid on the road. I will check the off road feel this weekend primarily how it handles Off-road, my suspension still seems soft.
 

 

[Nice Little Jeep]

1 hour ago, Redline said:

Before I switched to the 60s and had to redo lower mounts, My jeep was pretty happy with 250/275 in the front and 300/250 in the rear. I went with 300 over 250 in the rear because I needed the extra spring for ride height but did not want the extra spring when bottoming. 

Now that I have moved the lower shock mounts I am going to go to 250/250 in the front and 275/250 in the rear most likely because I have zero preload on the driverside and it is a little on the stiff side for me.

my understanding to run the lighter spring on the top and the heavier spring on the bottom.

 

Example: 250/300 (top/bottom)

[Nice Little Jeep]

2 hours ago, Redline said:

Before I switched to the 60s and had to redo lower mounts, My jeep was pretty happy with 250/275 in the front and 300/250 in the rear. I went with 300 over 250 in the rear because I needed the extra spring for ride height but did not want the extra spring when bottoming. 

Now that I have moved the lower shock mounts I am going to go to 250/250 in the front and 275/250 in the rear most likely because I have zero preload on the driverside and it is a little on the stiff side for me.

That’s where I’m at right now I have no preload on the driver side at 250/300 front and rear, but prior I was sitting on my bump shocks a lot, I was at 250/250 with 250 gas pressure. So put the gas down 150psi and increased the spring by 50 (300).

i also went from 12” bottom spring to a 14” bottom spring this gives me more adjustability at transfer rings. 
 

it feels good in the front and rear on the road I haven’t taken it off road yet. 
 

[KevinG]

On 11/24/2022 at 3:47 PM, Redline said:

SORRY!! I have been a little busy for the past few months and havent had time get on here.  

#1- I generally would never mix rates side to side. That will cause some ride issues that can never really be corrected. With C/Os you can add the extra preload to the passenger side to get the ride hieght pretty leve and then adjust cancel out rings to get the final ride nice. If you run different springs side to side it is always going to have a side kick when engaging the single rate as speed.

#2- Have found personally that 10" over 14" in the front and 10" over 12" in the rear seems to make the best combo for tuneability 

#3- I would not go above a 300lbs rate on any corner of a jk unless it was extremely loaded

#4- In the "ideal" world you have 1-2" of preload at full droop on your springs. That is the measurement of how much you springs combined are compressed and not just how far the preload nut is turned down.

#5- Eibach is a Much better spring. I love Kings and have been friends with Brett for a couple decades, but I choose Eibach over the others because have good experience with them and usually can get them same or next day.

#6- Charge your shocks min 150psi but 200-225 is better if really going to use them

Dude, awesome info.  I know things are probably super busy for you so no rush.  Would you mind expanding a little on #2?  Is the 10" over 14" because the rings only thread so far down the body?