School me: spring rates/lengths for coilovers

[1Sinner]

So I'm at the point I'm finally ready to throw my coilovers on complete with springs and set ride height. And I got some issues.... I originally went with Carbon offroad coilovers due to being and American owned, veteran run business, bit I haven't been that impressed since I bought them. I originally ordered with adjusters on the resi's. Adjusters failed sitting on the shelf after a few months. Called, there was an upcharge for new style adjusters that supposedly don't leak. Or they'd send a standard set of reservoirs at no cost. For the issues with the current reservoirs I just had standards sent.

I also had them spec springs, based on standard component weights and estimated weight of jeeptcagettire carrier etc and all accessories.

Well, after mockup with the coilovers and no springs, cage, body, wiring, engine and trans/transfer case all installed it was time to toss on the springs and set ride height.


For reference, I am running 16" with three link in the front, 14 inch in the rear on trailing arms. All steel body, 1.75 x .120 DOM cage, aluminum 6.0 LS2, 6L80E, dana 300, trussed 10 bolt front, trussed 14 bolt rear, full tube frame. Total estimated weight 4-4500lbs.


Spring box was sent with no identifiers or installation instructions (front/rear springs not identified) weights were on 2 of 8 springs. One was 300, one was 250. I used longer springs on fronts (16" bodies) 300lb bottom, longer unidentified lighter coil on top over the divider, rears have not yet been assembled.

As installed at full travel

With weight after standing and bouncing on the front bumper to settle the jeep. No additional compression on springs through adjusters, just set with no slop. Im about 8 inches too high.

I know the heavier springs should go on the rear, but I don't have any long enough (other springs are 14" tall).

What weights and lengths should I be running?

Talk about taking Carolina squat to the next level. Wtf. Seriously.

 

[ChrisRWG]

So you have 250/300 on the front right now and that's how high it is sitting?

It will also help to know the motion ratio on your trailing arms.

 

[1Sinner]

So you have 250/300 on the front right now and that's how high it is sitting?

It will also help to know the motion ratio on your trailing arms.

Not sure on the weight of the upper springs, the 250s are only 14" long so I set those back for the rears, the other 16 inch springs are on top and they are thinner wire than the 250s.

What do you want as far as motion ratio? Length of lowers vs upper?

 

[Wfoyota]

Youve got way to much spring. 16" shock usually needs two 16" springs and 14" shock usually needs 14 top and 16 bottom. Educated guess based on the years ive messed with coilovers, you need to be in the 150/200 area in the front and 200/250 area in the rear.

 

[ChrisRWG]

Not sure on the weight of the upper springs, the 250s are only 14" long so I set those back for the rears, the other 16 inch springs are on top and they are thinner wire than the 250s.

What do you want as far as motion ratio? Length of lowers vs upp

Motion ratio as in the ratio of shock travel vs wheel travel. Since you said you have trailing arms, that puts a lever on the shock which requires you to put a heavier spring on the shock.

Read this article on crawlpedia, it is going to help you in the right direction.

Off-Road Coilover Springs | How to Fix Your Coilover Springs

Crawlpedia is an off-road encyclopedia featuring a detailed explanation of how to correct coilover springs on a vehicle that are too tall, too short, too stiff, or too soft.

www.crawlpedia.com

Since you have a 16'' 250lb spring on the front, measure the amount it is collapsed so you can start calculating a corner weight. Once you know the corner weight, you can plug the unknown springs into the front, measure them, and figure out their spring rate.

 

[Bebop]

You need lighter rates and better springs so you know the rate is real. I agree with Wfoyota

I would start by measuring the rate of the actual springs you have since you don't know how accurate they are.

Make sure to do your measurements with the nitro in the shocks.

 

[ParadisePWoffrd]

Since you have a 16'' 250lb spring on the front, measure the amount it is collapsed so you can start calculating a corner weight. Once you know the corner weight, you can plug the unknown springs into the front, measure them, and figure out their spring rate.

This. Put 1 set of springs on the front and rear, and set the stops so that it is sitting at ride height. Measure how far the spring compressed at each corner, and multiple by the rate to calculate the weight on the springs. You can use that number to determine the setup you need.

Here is how to determine your springs' rate, if you need it: How To Calculate Spring Rates – How To Adjust And Tune Suspension Secrets

 

[1Sinner]

Thanks for the guidance so far everyone.

 

[Treefrog]

Look like others have spring rate stuff covered. I just want to mention that the 4 link calc finds installation ratios as vertical force/spring force. It can do trailing arms.

It's spring rate required estimate is a bit high since gas pressure is not accounted for.

 

[csutton7]

ParadisePWoffrd is correct on putting one spring on each corner --the 300lb springs on the front and the 250 lb springs on the rear or vice versa, that's up to you and doesn't matter for what you are measuring right now.

I've never heard about setting the stops at ride height, but there could be merit to it. I've just let the springs compress with the stops not set, as this will give you the true weight of each corner. If the 300lb springs compresses 4 inches then 4 x 300=1200lbs for that corner. Now you can proceed to figuring out the rates by using the Crawlpedia calculator, but with that being said be prepared to change the springs once or twice more once you get them installed and see what's really going on.

For the 16" coilovers guys way smarter than me told me to use an 18" spring on the bottom and a 16" on the top, but again your choice. Same goes for any size coilover always put a spring 2" longer than the coilover on the bottom. So a 16" coilover gets 18"/16", a 14" coilover gets 16"/14" and so on.

The heavier spring should always be the bottom spring.

Keep your top and bottom spring within 100lbs of each other.

In my '48 Willys thread over on the other site I have a ton of info about how to set up, calculate, etc if one wants to go back to read it or I'll see if i can copy all of that info and somehow paste it on here.

 

[csutton7]

Sorry to those who don't need this info that's coming forth cuz it's a lot, but it it helps then it was worth it--from my '48 build

#730 · May 11, 2015

Have you calculated your corner weights using the coils you have now?

how far down are the top nuts now?

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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Joined Jun 1, 2001
3,197 Posts
Discussion starter · #731 · May 11, 2015

mieser-- trying to figure it out---i know the rates & i know how much they are compressed but the nuts are screwed down 3-4"(not official measurement-need to measure tonight)---

So I know parts of the equation but not the part that tells you what happens when you put on the springs and you get some compression, but not enough, but I don't know the equation if you're compressed to far.

initial equation is: (spring A x spring b)/(spring A + spring B)
Front (110 x 200)/(110 + 200)
22,000/310=71
Rear (100 x 150)/(100 + 150)
15,000/250=60

So right now my rear is compressed(not good in any faction of life) and I mean totally compressed. So you now do this:

compression of springs =14"(rears are totally compressed) and you multiply it by 60 from above and the fronts are" 12.5 compressed:

rear 14 x 60=840
front 12.5 x 71 = 887.5

but the adjusting nut is screwed down a few inches(again verify tonight)---so are my compressions not good....this is where it gets tricky, because I'm not sure I can use the rear #'s since they coils are compressed. I don't think I'm getting a true calculation. The front I can calculate, but do I need to unscrew the adjuster to see what happens when coils are totally extended or could be totally extended, if they were strong enough??????

I got this info from page 111 of this article, but it only gives you one side of the equation and it doesn't say where you should have the adjusting nut in the calculation stage(I'm thinking all the way up to the top, but I don't know for sure)

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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#732 · May 11, 2015 (Edited)

or I find somewhere to weigh the corners and then I'd know what to do....

You can calculate near perfect sprung corner weights using the springs you have now.

Edit....hit send too soon.

It would likely be easier to calculate the corner weights in your case without a second spring. You need to the suspension to be at least holding itself off the bumpstop.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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Mieser​

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#733 · May 11, 2015

Also. The adjusting nut can be moved down, but it is easier to calculate the spring rate if your not 'preloading' the free length of the coils. IE. If the shocks are fully extended, is the top nut screwed down further than the free length of the coils?

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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Mieser​

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#734 · May 11, 2015

And....

What length are all your existing coils?

front: 110/200
rear: 100/150

We will need that too.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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3,197 Posts
Discussion starter · #735 · May 11, 2015 (Edited)

I want to say they are 14" coils, but I'm not sure....but the rears do have a tender spring, so now I'm not sure....

yes the adjusting nut is screwed down--I want to say like 3" or so....could be more..

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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#736 · May 11, 2015

I want to say they are 14" coils, but I'm not sure....but the rears do have a tender spring, so now I'm not sure....

yes the adjusting nut is screwed down--I want to say like 3" or so....could be more..

How hard is it for your to full extend the suspension and pull the coils?
Your going to need to do that....at least twice likely.
We are going to need the coil lengths too.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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[csutton7]

Discussion starter · #737 · May 11, 2015 (Edited)

the shock is 35.5 long eye to eye when extended, so I'm now thinking that they are 14" long coils--I don't remember them being loose when I installed them long ago--man I don't recall if I adjusted them or not(seems I must have) or if I have an adjusting wrench--looks like I'm on the tear the garage apart tonight to see if I have one...


ok from that article I was reading it said if you wanted 7" up travel and 7" droop and your springs only compressed 6" your springs were to stiff, so once you had the weight(in this scenario it was 600lbs) you would take the weight and divide it by 7"(your desired ride height setting)

600/7=85.7 which turns out to be 150 over 200 in the spring depts
(150 x 200)/(150 + 200)= 30,000/350=85.7

but I'm over compressed and I need to extend(need stiffer) and not compress, so what's the proper calc??

so would I take 887.5/5? 5 being the amount of my up travel or my ride height setting. Or since I have 14" springs do I use 887.5/7? 7 being the halfway point and then I adjust the nut to give me what I want for compressions and droop?

887.5/5=178 300/450 springs in this case---seems way wrong
887.5/7=127 200/350 springs in this case---seems closer to what I need, but again is the math right?

840/5=168 300/400 springs in this case--again seems wrong
840/7=120 200/300 springs in this case--seems closer

Or since I want 9" of droop is that the number I should be using

887.5/9=99 175/250 or 200/200
840/9=93 150/250

I'm all ears to any and all on this.....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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#738 · May 11, 2015 (Edited)

I'm all ears to any and all on this.....

You need to double check all the compression measurements on the springs along with spring lengths and top nut pre-load.

Don't assume.

Personally. I would pull a spring and just use the heavier coil to calculate corner weight. All you need to do is run the top nut down low enough that the suspension is fully off the bumpstop. If you know the length and rate of the single coil is it easy to measure collapsed length. Then you can easily calculate the corner weight since you know the spring rate.

That gives you a very good number for UN-sprung weight at each corner of the vehicle.

You can calculate sprung weight with your dual rate but you need to make sure you don't have any 'preload' on the free length of the springs. Or you know exactly what the preload is.

You want 5" of shaft showing ( at ride height ) front and rear correct?

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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3,197 Posts
Discussion starter · #739 · May 11, 2015

been playing with BV's coil over spring calculator- and I don't quite understand all of it--but like you say Meiser I need to know the length--I think if I jack it up to full droop and back off the adjusting nut and see if I can remove the lower spring keeper that will do it, but we shall see---again I'm pretty sure they are 14" coils.

Using the info I have now it looks like my weights are 964 front and 793 rear, but I'm not trusting my "NOW" info until I jack and back off nut and then set it back down to see what happens---I may have to use the 150/200's on the rear to get the proper calcs to be able to move forward on the rear.


Pirate4x4.Com - The largest off roading and 4x4 website in the world.




Corner Sprung Weight Calculator ~ User entered values are in green text
~ Calculated values are in black text, average in blue text
LEFT FRONT RIGHT FRONT LEFT REAR RIGHT
REAR
Step 1- Calculate Installation Ratio
d1 (in) 41 41 35 35
d2 (in) 41 41 35 35
alpha (˚) 0 0 0 0

DR 1 1 1 1
ACF 1.0000 1.0000 1.0000 1.0000
IR 1.0000 1.0000 1.0000 1.0000

Step 2 - Calculate Coil's Spring Rate (skip if rate is known)

Dw (wire diameter) (in) 0.5 0.5 0.5 0.5
Di (inside diameter) (in) 2.5 2.5 2.5 2.5
Dm (coil mean diameter) (in) 3 3 3 3
Na (number of active coils) 12 12 12 12
K (spring rate) (lbs / in) 271 271 271 271

Step 3 - Enter Spring Rate (either manufacturer's spec or calculated in step 2 above)

Main Spring - Rate (lbs/in) 200 200 150 150

Tender Spring - Rate (lbs/in) 110 110 100 100

Combined Spring Rate (lbs/in) 70.96774194 70.96774194 60 60

Step 4 - Calculate Spring Deflection at Ride Height

Main Spring - Free Length (in) 14 14 14 14

Main Spring - Length at Ride Height (in) 8 8 8 8

Main Spring - Deflection at Ride Height (in) 6 6 6 6

Tender Spring - Free Length (in) 14 14 14 14

Tender Spring - Length at Ride Height (in) 7 7 7 7

Tender Spring - Deflection at Ride Height (in) 7 7 7 7

Combined Springs - Free Length (in) 28 28 28 28

Combined Springs - Length at Ride Height (in) 15 15 15 15

Combined Springs - Deflection at Ride Height (in) 13 13 13 13

Step 5 - Calculate Corner Sprung Weight from the spring rate, the installation ratio, and the spring deflection

Corner Sprung Weight - by Main Spring (lbs) 1200 1200 900 900

Corner Sprung Weight - by Tender Spring (lbs) 770 770 700 700

Corner Sprung Weight - by Combined Springs (lbs) 923 923 780 780

Corner Sprung Weight - average (lbs) 964 964 793 793

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:

 

[csutton7]

3500lbs in sprung weight seems very high to me.

That doesn't include your axles, tires, wheels, half you links, half you driveshaft, brakes, etc.

Discussion starter · #741 · May 11, 2015

Yes on the 5" of shaft showing--anything more and I can't drive the jeep in the garage!!! But I didn't really set it up for garage entering. I always wanted 5'' up and 9" down. I'm not sure why I picked those #'s but I did long ago and then built along those lines.

Seems like I would compress the 200lb spring completely if I were to only use it vs using the 150/200, as I know the 150 over 200 at least gives me 1.5" of up travel and 12.5" of droop on the front.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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TimCubed​

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#742 · May 11, 2015 (Edited)

Dam that's a lot of numbers, The numbers or on the side of the springs 1/16 print should say 1200=12"......1400=14".........1600=16" shocks
250 is the size of coil,..0150 is the weight of the spring.
I think you should just call your 4x4 shop your dealing with to see what kind of used springs they have laying around for sale or trade or just borrow. Most coilover guys have extra springs laying around. rockme may have some I have 1pr. 14" 150lb. for you


We have totally different rigs but here is what I have.
Front 1200x250x.0175 over 1200x250x.0275 200psi gas
Rear 1400x250x.0100 over 1400x250x.0250 150psi gas
all shocks revalved to slow down compression and rebound

'44 GPW Stretched and Linked
'51 Willys bigger Stretch bigger Links
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csutton7​

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3,197 Posts
Discussion starter · #743 · May 11, 2015

Tim--yea I figured out what all those #'s meant--the shop who charged my shocks didn't have any coils around:( , so that's why I'm now going down this path--I sent rckme52 a PM, but he hasn't responded.

I'm not sure 150lbs will do what I want, but I'll let you know once I have something figured out. Of the ones I have I'd really like to use the 150/200's on the rear and I may do that for awhile if I could, and if I can get by with 150/250's up front I'll definitely be talking to you.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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10,914 Posts
#744 · May 11, 2015

Tim--yea I figured out what all those #'s meant--the shop who charged my shocks didn't have any coils around:( , so that's why I'm now going down this path--I sent rckme52 a PM, but he hasn't responded.

I'm not sure 150lbs will do what I want, but I'll let you know once I have something figured out. Of the ones I have I'd really like to use the 150/200's on the rear and I may do that for awhile if I could, and if I can get by with 150/250's up front I'll definitely be talking to you.

Talking with a friend...

If you can get the shocks fully extended.
Back off the top nut to make sure there is zero preload ( or loose )
Run the secondary stop down till it touches the dual rate slider
Now set the weight of the chassis on just the LOWER spring.

If you basically lock out the second spring you are on a single spring rate system.

If the bottom coil is 200 lbs/in you have a 200lbs/in spring rate.
You know the free length of the spring is XX" ( you guessed 14" ).
If the spring compresses 1" you have 200lbs for sprung corner weight
If the spring compresses 2" you have 400lbs for sprung corner weight
If the spring compresses 3" you have 600lbs for sprung corner weight
etc
etc.

You should be able to do this to get an accurate sprung corner weight measurement for all 4 corners. In the front you would be using your 200lb lowers in the rear you would be using your 150lb lowers.

This should be easier to measure if your basically fully collapsing your current dual rate springs....71in/lb rate in front and a 60in/lb rear weight.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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[csutton7]

Discussion starter · #745 · May 11, 2015

thanks Mieser--I'll give it the ol college try and report back--could be a couple of nights worth of work (or more) though.....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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10,914 Posts
#746 · May 11, 2015

thanks Mieser--I'll give it the ol college try and report back--could be a couple of nights worth of work (or more) though.....

Just try and work through logically. To do that we need good sprung corner weights.

Start with one end. We might be able to switch some of the springs around to make it work ok at least on one end.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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3,197 Posts
Discussion starter · #747 · May 11, 2015

yep that be the plan--fingers crossed I can use the 150's and 200's somewhere and only have to buy 4 springs--now does anyone know how to sneak money out of the ball and chain's purse!!!!

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Overhauler​

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Joined Aug 16, 2010
692 Posts
#748 · May 11, 2015

I'm assuming you got your shocks charged with nitrogen. I was digging thru some stuff that my dad and I had stashed over the years and I have a Nitrogen regulator and hose with fill fitting. I'm not sure if its the same kind used for your shocks. This one is aviation style. If this looks like something you could use let me know.

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"No Toyota Tech Here"

37s on 1/2 tons were Obama's America
44s and 1 tons are Trump's America.

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csutton7​

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Discussion starter · #749 · May 11, 2015 (Edited)

overhauler--thanks--yes I got them charged to 200psi, so that part of the equation is complete--the sway-a-ways have a shraeder valve fitting, so if that's what the one part will screw on to then it would work.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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MotoDave​

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546 Posts
#750 · May 11, 2015

Been following along - also curious to see what you come up with for real-world corner weights.

Check out the Coilover spring trade thread, may be able to trade your coils for hat you need, or at least sell your un-used ones.
Coilover springs for sale or trade

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Overhauler​

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692 Posts
#751 · May 11, 2015

I'm missing the -4 to pipe thread fitting. I bet I have one around here.

"No Toyota Tech Here"

37s on 1/2 tons were Obama's America
44s and 1 tons are Trump's America.

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csutton7​

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3,197 Posts
Discussion starter · #752 · May 11, 2015

I was on the coil over trade thread earlier today, but thanks for posting the link here--I should've done that, but got busy with other things....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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csutton7​

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Discussion starter · #753 · May 12, 2015 (Edited)

OK--jacked up the front and the springs are 14" long....

adjusted the nuts down to just put load on the bottom 200lb springs for each side and both springs compressed 5", so 5x200=1000lbs

the rear is still sitting on the bump stops--will that make a difference??

also I'm sitting at 1"-1.5" of my proposed ride height in the front, which surprises me, but only because I expected it to compress closer to where it was and I need to just turn it over in my head how moving the adjuster nut up made that difference when I thought I had to run it down to get ride height.

now have to do some math to figure out what spring rates to use....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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[csutton7]

#754 · May 12, 2015

So you moved the dual rate stop so that only the bottom spring (14" long, 200 lb/in) was carrying any of the weight, right? Top spring was basically loose, just along for the ride.

Remember, when you have both springs in series the combined spring rate is lower than each spring individually. So at your combined rate of 71 lb/inch, that same 1000 lb corner weight was compressing the spring more.

If you want 5" of shaft showing with 2" of preload dialed into the springs at full extension you want a target combined rate of 91 lb/in. Maths behind that: Total spring compression will be 11" (2" of preload + 9" of bump). 1000 lbs corner weight / 11" compression = 90.9 lb/in.

Changing the upper spring to 175 lb/in and keep your 200 lb/in lower gets you 93 lb/in combined, close enough.

If it were me I'd do the same thing in the back, the weight transfer of the back end sitting on bump stops shouldn't affect the front numbers too drastically but as you know them springs ain't cheap, better to get some good numbers and get closer to a baseline first try.

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Mieser​

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#755 · May 12, 2015 (Edited)

now have to do some math to figure out what spring rates to use....

So 1000lbs per corner spring load in FRONT. That is higher than I would have guessed personally. ( And I think it is actually 1100lbs or so since you have a charge on the shocks ) USE 1000 though!

You need to compress the front springs a minimum of 9" to give you 5" of shock travel remaining on your 14" travel shocks. If you add in 3" of preload to that you would need 12" of compression.

1000lbs/9" = 111lbs/in
1000lbs/12" = 83lbs/in

I think that is your reasonable rate window for your combination. With the 111lbs/in rate you would need ZERO preload on the top nut. With 83lbs/in you would need a full 3" of preload on the top nut to give you 5" of shaft showing at right height.

I would keep your springs under a 100lbs/in difference. If you have more than that you risk blocking the lighter upper spring on compression and HAVING to use the dual rate stop on the last inch or two of travel. It is better not to HAVE to do that.

I would use a lower coil spring that is 2" longer than shock travel. That keeps the dual rate slider a little higher on the shock body at full extension.

Try and keep preload between 1" and 3" with 2" being a good goal so you can make some final adjustments. Remember, your likely going to see a pretty big change in ride height as you add people and gear. I would try and lean toward 1" of required preload in the REAR in your 'light' configuration. Your front weight won't change THAT much unless you are packing things really odd.

Don't expect miracles just yet. I have a feeling your going to need some shock tuning for sure. Do you have any idea on valving? If it is set light on compression you may bottom out more often than you would like with only 5" of uptravel. Don't be tempted to adjust the spring rate outside of the window suggested to try and fix that issue.

Edit: dam bit...dave beet me :)

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Mieser​

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#756 · May 12, 2015

For front spring options....

250/200= 111lbs/in
250/175= 102lbs/in
200/200= 100lbs/in
200/175= 93lbs/in
200/150= 85lbs/in

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csutton7​

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Discussion starter · #757 · May 12, 2015

MotoDave--yes that's exactly what I did. But man how'd you do that math to figure all that out. Not that I'm a math nerd, I just like to know how things work. I can't THANK YOU enough for doing that for me, but can you decipher how you came up with 11"??????

I understand the 2" preload but what does 9" of bump mean?? does bump mean what's left of the springs to do their job? Is that just coincidence that I want 9" of droop? my head is spinning!!!

14" coil on each coil subtract 2" of preload=12" on each coil left. Do you not count the first 1", so a 14" coil is really 13" subtract 2" preload=11"?? This is what I don't understand how 11 came into the picture!!!!

I get the 1000/11=90.9 and I understand the math behind 175lb over 200lb springs.

I will be attacking the rear tonight if all goes well and reporting what I find out.

Thanks again....

--my '48 build: not a build thread, but kind of is--just tryin to help...
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Mieser​

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#758 · May 12, 2015

Since the math you did a few pages back was really close for the front 964 vs 1000 final. It looks like you probably have about 800lbs rear corner SPRUNG weight. I would still double check....

If that is the case you need a spring rate between 89-67lbs/in in the rear. I would tend to error towards the higher end of that range and less preload since you are likely going to be adding a significant amount of cargo/people weight.

I would shoot for about 1" of rear preload in the 'light' setting so you can still get it in the garage. That would give you about 2" more preload to adjust ride height with cargo/people on bigger trips.

200/150 = 85lbs/in
200/125 = 77lbs/in
200/100 = 67lbs/in

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#759 · May 12, 2015

MotoDave--yes that's exactly what I did. But man how'd you do that math to figure all that out. Not that I'm a math nerd, I just like to know how things work. I can't THANK YOU enough for doing that for me, but can you decipher how you came up with 11"??????

I understand the 2" preload but what does 9" of bump mean?? does bump mean what's left of the springs to do their job? Is that just coincidence that I want 9" of droop? my head is spinning!!!

Thanks again....

You need to collapse the springs a minimum of 9" to have the 5" of remaining shaft showing ( uptravel ) you wanted at ride height. You don't want the springs to become loose when the shocks are fully extended.

MotoDave then added in 2" of preload on top of that to give you the 11" figure. As you add shock preload the spring rate you need to hold up the vehicle at the same point goes down.

In my calcs I gave you a window. The high rate requires no preload. The low rate requires 3" of preload. Both those options give you the same final ride height.

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csutton7​

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Discussion starter · #760 · May 12, 2015

Mieser--you is moving to fast for me(don't pat yourself on the back--I'm slow)--but really thanks---I just need to reread what you first typed so I can see if I can fathom all of that. I do think you're right that I'm probably a bit heavier and I still want to add tube under my fenders and a tube at the front of the grill and may have to still stretch the front hood for a better radiator and maybe an air compressor, so I'll be adding weight.

now back to read what you first typed up after MotoDave's response....thanks again....

--my '48 build: not a build thread, but kind of is--just tryin to help...
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[csutton7]

Discussion starter · #761 · May 12, 2015

I have no information about current valving--

Bottom line I can and will use the 200lb springs somewhere, so that makes me happy and hopefully I can use the 150lber's in the rear....that means only 4 springs I need to buy---

Summit has QA1 springs for $37.97 ea--are these good springs??

Mieser--I'm kind of digging the 16" lower spring idea, but compressing it to get it on the shock may take some doing and maybe not--need to think about that more--

Summit Racing's -QA1 stock doesn't have 16" noted--would have to call them....

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#762 · May 12, 2015

I have no information about current valving--

Bottom line I can and will use the 200lb springs somewhere, so that makes me happy and hopefully I can use the 150lber's in the rear....that means only 4 springs I need to buy---

Summit has QA1 springs for $37.97 ea--are these good springs??

Mieser--I'm kind of digging the 16" lower spring idea, but compressing it to get it on the shock may take some doing and maybe not--need to think about that more--

Summit Racing's -QA1 stock doesn't have 16" noted--would have to call them....
Click to expand...

QA1 spring review from years back.

QA1 coilover springs vs Eibach

16" lowers should work. I would just measure how much room you have and make sure its not too tight. Running lowers 2" longer than shock travel with uppers the same as shock travel is fairly common.

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#763 · May 12, 2015 (Edited)

MotoDave--yes that's exactly what I did. But man how'd you do that math to figure all that out. Not that I'm a math nerd, I just like to know how things work. I can't THANK YOU enough for doing that for me, but can you decipher how you came up with 11"??????

I understand the 2" preload but what does 9" of bump mean?? does bump mean what's left of the springs to do their job? Is that just coincidence that I want 9" of droop? my head is spinning!!!

Sorry, I think I confused Brennan with the same thing - hangup from a past job, I tend to reference everything from full droop so to me 9" of bump means 5" of shaft showing on your 14" shock.

I picked 2" of preload as a rule of thumb, Brennan's calcs are more general to give you a range of spring rates that will get you in the ballpark, then you can dial it in with the preload adjuster.

14" coil on each coil subtract 2" of preload=12" on each coil left. Do you not count the first 1", so a 14" coil is really 13" subtract 2" preload=11"?? This is what I don't understand how 11 came into the picture!!!!

The coil length does not matter right now, but you've got that a bit backwards. The preload is applied to the combined spring, not each spring separately. In fact, there's no real reason to think of the springs separately at all right now, just work off of having one big spring with some known rate (93 lb/in if you go that route).

The total amount you're compressing the combined spring at ride height is preload (2") + the amount of bump travel (14" shock - 5" shaft showing = 9").

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csutton7​

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Discussion starter · #764 · May 12, 2015

MotoDave--so you take 2" preload and added that to the "bump" and that gave you 11 and from there the math takes over to start spring purchase....

I think I'm going to lean on the heavier side of things and maybe go with 200 over 200 or 200 over 250 or 175 over 250(if 200's work in the rear)---I want to use my set of 200, but I'm curious as to what you would do??

Mieser--thanks for the link--QA1 looks fine--

 

[csutton7]

damn 16" springs take a jump in price---going to force me to stay with 14" possibly, unless I'm lucky and can find some 16" used for a decent price(emailed a guy)....if could sell some of my stuff in the garage thread, then I'd fork out for the 16" ones no problem....

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#766 · May 12, 2015

MotoDave--so you take 2" preload and added that to the "bump" and that gave you 11 and from there the math takes over to start spring purchase....

I think I'm going to lean on the heavier side of things and maybe go with 200 over 200 or 200 over 250 or 175 over 250(if 200's work in the rear)---I want to use my set of 200, but I'm curious as to what you would do??

Mieser--thanks for the link--QA1 looks fine--

Yep you've got the Maths figured out now :)

The base formula for spring force is F=kx, k is the spring rate, x is deflection from free length. All we're doing is playing with that formula in different ways.

I would to the same measurement in the back, this gets you a real number for corner weight there (we're assuming some things to get to the 800 lb spring weight, better to have real numbers before buying anything). This will also get the truck sitting level to make sure the weights aren't thrown off significantly.

In theory the front weight won't change as much as the rear with added cargo. I'd probably go for the 200/175 combo in the front with 2" of preload, and go stiffer (200/150) in the rear with 1" of preload - this gives you room to dial in more preload if needed to carry more weight.

Brennan is right about using a 16" spring on the bottom and 14" on top - I don't think you will have to compress them to get them on the shock, shock body should be ~35" long (based on the Fox catalog)

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csutton7​

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Discussion starter · #767 · May 12, 2015

MD--thanks for the help again...yea tonight I'll be jacking up the rear and backing the top adjuster nut up and the stop nut down and let her sit on the 150lb springs only to get the true weight. You are probably right about not having to compress a 16" spring much to get them on. My SAW's are 35.57" extended and I think that's eye to eye.


The guy will sell me his 16" 200lb Eibachs, but of course they're on his rig and until he gets replacements they will stay on there--I'm not sure I can wait--although what's few weeks after being gone for 2 yrs and have a problems with the rig for 2 yrs and getting 16" for a great price----not much, but now I think I'm too anxious to wait----

QA1's in 14" may just win out....

--my '48 build: not a build thread, but kind of is--just tryin to help...
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#768 · May 12, 2015

I would try and maintain at least 1" of preload in the front if your going to sway towards the higher ratio. That means less than 100lbs/in. Even if you add weight your going to be able to dial in another 2" which will support another 200lbs of added SPRUNG weight give or take. With that in mind I would say 200/175 if I could pick and choose....

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csutton7​

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Discussion starter · #769 · May 12, 2015

Mieser--thanks---looks like 175 over 200 is the winner, so unless this guy sells me his 16" I'll be going with all 14" coils cuz the new 16" are out of the budget--I hate doing it, but such is life. Plus if I have to change I won't cry as much with $40 springs sitting on my floor vs $110 springs.....

One thing now is I may be able dial in my ride height with the springs I have to see how it sits and I'll probably drive it just to see how it feels and I can compare to the new set up until I get the new springs. Of course this is predicated on the rear doing what the front did concerning backing off the adjusting nut and lowering the stop nuts.

Next question is where to put the stop nuts on the new set up, is there a measurement for that which is determined by your springs or ride height or you just set them where you won't bottom out the shock???

--my '48 build: not a build thread, but kind of is--just tryin to help...
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Mieser​

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#770 · May 12, 2015

Mieser--thanks---looks like 175 over 200 is the winner, so unless this guy sells me his 16" I'll be going with all 14" coils cuz the new 16" are out of the budget--I hate doing it, but such is life. Plus if I have to change I won't cry as much with $40 springs sitting on my floor vs $110 springs.....

One thing now is I may be able dial in my ride height with the springs I have to see how it sits and I'll probably drive it just to see how it feels and I can compare to the new set up until I get the new springs. Of course this is predicated on the rear doing what the front did concerning backing off the adjusting nut and lowering the stop nuts.

Next question is where to put the stop nuts on the new set up, is there a measurement for that which is determined by your springs or ride height or you just set them where you won't bottom out the shock???

Uhhhhh. I wouldn't drive around on just the bottom springs using the dual rate stop?? That isn't a good idea at all. You will trash the slider in short order.

In order to calculate IF you need to use the dual rate stop we need the manufacturer (along with length, rate) of each spring. Different manufacturer springs have different block heights. We may or may not be able to find this information.

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Discussion starter · #771 · May 12, 2015

I wasn't going to drive around on the bottom spring, just going to adjust it some so I can see if it what will happen to get it less compressed like it was, by adjusting the stop up and bringing the top nut down a bit---I can't do much as I don't have a wrench, but a 5/16" all thread did fit in the holes, so I'll have to jack it back up do some nut adjustment and see what happens

looks like the guy is going to sell me his 16" Eibach 200's---so depending on how things shake out in the rear I'll either be going my 200's over the 16" 200's on the front or new 175's over the 16" 200's in the front. Hopefully the rear may be 100/110/ or 150 over the 200's that I have and 16" lowers can come down the road. I will put what I have left on the coil over trade thread and see if I can trade them for 16".

--my '48 build: not a build thread, but kind of is--just tryin to help...
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Mieser​

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#772 · May 12, 2015

I wasn't going to drive around on the bottom spring, just going to adjust it some so I can see if it what will happen to get it less compressed like it was, by adjusting the stop up and bringing the top nut down a bit---I can't do much as I don't have a wrench, but a 5/16" all thread did fit in the holes, so I'll have to jack it back up do some nut adjustment and see what happens

looks like the guy is going to sell me his 16" Eibach 200's---so depending on how things shake out in the rear I'll either be going my 200's over the 16" 200's on the front or new 175's over the 16" 200's in the front. Hopefully the rear may be 100/110/ or 150 over the 200's that I have and 16" lowers can come down the road. I will put what I have left on the coil over trade thread and see if I can trade them for 16".

Oh ok. I was worried for a second :)

I would get a spanner for the top nut. You are going to need that in the long run, especially for the rear if you need to change the preload for added weight.

You don't want 100# of rate difference between the upper and lower spring. You will likely fully block out the lighter top spring and HAVE to use the dual rate stop. This will cause you HAVE to go from your combined rate of only 66lbs/in ( with a 200/100 ) up to 200lbs/in for the last 1-2" of travel. It might be a decent tuning tool to use the dual rate, but I wouldn't want to HAVE to do it.

200/150 = 85lbs/in
200/125 = 77lbs/in
200/100 = 67llbs/in

The 200/100 combo is the bottom of the spring rate you need for the rear at 800lbs of sprung weight. That would require running the most preload...approaching 3" for sure. You want more like 1" in the rear so you have some margin to deal with added cargo/people weight. I would shoot for the 200/150 combo in the rear since your going to basically add 1-2 people right away just going for ice-cream :)

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csutton7​

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Discussion starter · #773 · May 12, 2015

Yea I doubt the 100 or 110 will be used, just don't want to rule them out, but I must thank you again about the 100 rule diff--I need to pound that into my pea brain!!!! Will be interesting to see what the rear corner weights are tonight.

10-4 on the spanner wrench--I'm not sure why I think I have one, but I'll be damned if I know where it's hiding and right now and I can adjust things by hand or with the 5/16" all-thread when I've got it jacked up with no pressure. But who wants to continue to jack things up all the time especially when I need to dial it in. Maybe I'll try and make one!!!

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csutton7​

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Discussion starter · #774 · May 12, 2015

forgot to mention that the rear has the triple rate set up--that shouldn't change anything if I recall, should it??

any reason to add a triple rate kit to the front??

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#775 · May 12, 2015

forgot to mention that the rear has the triple rate set up--that shouldn't change anything if I recall, should it??

any reason to add a triple rate kit to the front??

ditch the triple rate on the rear, don't add to the front. My opinion.

The triple rate will make it harder to get a 'free' upper coil for measuring the rear sprung weight.

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csutton7​

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Discussion starter · #776 · May 12, 2015

thanks--I'll see how it goes tonight. I really don't want to unbolt anything yet until I have all the parts in hand, but I have that feeling that this is going to force me to do so!!! I'm not sure why the guy had it installed--maybe one of the rear coils isn't 14"??? I'll be finding out.

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[csutton7]

Discussion starter · #777 · May 13, 2015

no luck last night getting the weight of the rear--I can't jack up the jeep far enough in the garage to get the shocks off to remove the triple rate stuff removed and adjust things to set it back down to measure spring compression. My garage needs to be 2-3 inches taller. So I'm going to try and leave work after 8 hrs today so I can pull it out of the garage and go to town.

I will be buying the 16" 200lb eibachs from a guy here on pirate today--should have them early next week....

--my '48 build: not a build thread, but kind of is--just tryin to help...
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#778 · May 13, 2015

no luck last night getting the weight of the rear--I can't jack up the jeep far enough in the garage to get the shocks off to remove the triple rate stuff removed and adjust things to set it back down to measure spring compression. My garage needs to be 2-3 inches taller. So I'm going to try and leave work after 8 hrs today so I can pull it out of the garage and go to town.

I will be buying the 16" 200lb eibachs from a guy here on pirate today--should have them early next week....

air down the tires to let the axle drop further?

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csutton7​

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Discussion starter · #779 · May 13, 2015

yea I thought of that, but it was getting late and I hadn't eaten dinner yet, so I said screw it and then I just figured I'll pull it out tomorrow as that would be faster--

money has been sent for the 16" coil overs----should have them Monday or tuesday next week....

It does look like the coils on the rear are 14" also--definitely the bottom one is and the top was measuring right at 12" before I got stopped, so I'm guessing that it's 14" also.....

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csutton7​

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Discussion starter · #780 · May 13, 2015 (Edited)

I decided to deflate the tires instead of pulling it out of the garage, just in case I had issues. So deflation commenced and I had to deflate them all the way to get the shocks off

150lb springs compressed 6.5" for the rear...but I have at least ¾ or more of fuel in the tank--not sure how that plays into the equation??

6.5 x 150=975 means basically same as the front....175 over 200 or I just run the 150 over 200 for now and see how it goes and in the future up it to 175 over 200 if needed

or I go 150 over 250, but then there's that 100lb difference to stay away from, so that doesn't work----crap I wanted to only buy 4 springs, but I defer to what you guys think....

let me know what you guys think.....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:

 

[csutton7]

#784 · May 14, 2015

I decided to deflate the tires instead of pulling it out of the garage, just in case I had issues. So deflation commenced and I had to deflate them all the way to get the shocks off

150lb springs compressed 6.5" for the rear...but I have at least ¾ or more of fuel in the tank--not sure how that plays into the equation??

6.5 x 150=975 means basically same as the front....175 over 200 or I just run the 150 over 200 for now and see how it goes and in the future up it to 175 over 200 if needed

or I go 150 over 250, but then there's that 100lb difference to stay away from, so that doesn't work----crap I wanted to only buy 4 springs, but I defer to what you guys think....

let me know what you guys think.....
Click to expand...

Fuel weight should work out fine. A full tank won't add that much weight nor last that long.

I am more concerned that the weight on the rear of the jeep is going to change with people and gear fairly quickly. I'm guessing you don't have tools, spare parts, or people in the vehicle at this weight. Your also going to need some margin for gear on overnight trips and such.

I would error to the high side of the spring rates we discussed for the front since the weight and stance needs to be about the same as the front. Those spring rates where...

250/200= 111lbs/in
250/175= 102lbs/in
200/200= 100lbs/in
200/175= 93lbs/in
200/150= 85lbs/in

You have....

110/200
100/150
And just bought another set of 200# springs.

For the budget option....

I would do 200/150 in front, and 200/200 in the rear.

The front isn't going to change much. The rear is going to change the minute you put people and gear in it. The 200/200 in the rear should give you about 1-2" of extra preload available for gear. At 100lbs/in that is up to 400lbs of adjustment in the rear pair without getting a bit too high on the spring preload. The front 200/150 is going to need about 3" of preload to get 5" of shaft showing.

In the future you could swap the 200/200 to the front pretty easy if you feel it's too soft and then be able to go up or down on the rear rate with only buying one more pair of springs on top ( which could be cheaper 14" QA1s)

Hope that helps.

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csutton7​

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Discussion starter · #785 · May 14, 2015 (Edited)

at the moment there's no rear seat, so no people will be in the back it will be only gear for a while anyway....


thanks so much for helping & I'm leaning to 200/200 for the rear & do the 150/200 for the front like you suggest Mieser--just makes sense for now..

still have two questions--how did you figure the pre-load? I can't wrap my head how you get those.

what about the secondary stop height, how do figure out where to set it?

again thanks....

--my '48 build: not a build thread, but kind of is--just tryin to help...
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Mieser​

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#786 · May 14, 2015

still have two questions--how did you figure the pre-load? I can't wrap my head how you get those.

again thanks....

Preload is pretty easy....

If you want ZERO preload you only have to compress the springs enough to get the height you want. If you have a 14" travel shock and need 5" of shaft showing you need to compress the springs 9". Zero preload always requires the highest spring rate.

1000lbs/9" of compression = a rate of 111 lbs/in

If you want to add preload to the system you need to add distance to how far you compress the system to hold the rate. This will always bring the spring rate down. 3" is about the most preload you want to run. More than that can start to cause coil bind issues.

1000lbs/(9" of compression + 3" preload) = a rate of 83 lbs/in

Next up...secondary stops.

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[csutton7]

Discussion starter · #787 · May 14, 2015

ok, let me see if I can make sense of this in one brain cell. So if I'm going to use the 150 over 200's this is combo is equivalent to 83lbs per inch. Knowing I want 5" of shaft showing and 9" of shaft inside the shock body. So I take 1000/83 which equals 12 and the difference between 12-9=3, so 3" of preload.

So let's do a test run---let's use 200 over 200--this calcs out to 100lbs per inch--(200x200)/(200+200)=100, so 1000/100=10 10-9=1
1" of preload

is that correct???

ok now enlighten what's left of my one brain cell on stop nut location.....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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Joined Jun 17, 2001
10,914 Posts
#788 · May 14, 2015

Secondary stops.

They can be a tuning tool. It is nice NOT to HAVE to use them to prevent blocking out the typically softer upper coil. When the dual rate slider hits the rate stop you are changing the spring rate.

Spring rate = ( lower spring rate * upper spring rate)/(lower spring rate + upper spring rate)

The secondary rate is JUST the spring rate of the lower coil once the slider hits the stop.

In example if your running a 200/200 spring combo your combined spring rate is 100 lbs/in. (200*200)/(200+200)= 100. Your spring rate will be 100 lbs/in till the slider touches the stop. Then the spring rate will go to 200 lbs/in.

You are basically doubling the spring rate at a minimum once the slider hits the stop. As the upper and lower spring rates get further apart so does the transition between the primary and secondary rate. If you where running a 200/100 combo you would have a primary rate of 66 lbs/in while you would still have a 200 lbs/in secondary rate.

The only reason to HAVE to worry about the dual rate slider is when you might have a rate difference so great between the upper and lower springs that you risk blocking the upper spring before full compression. Different rate springs compress at different rates :)

We can use the case of a 200/100 spring combo. The lower being a 16"x200 and the upper being a 14"x100.

You need to know how much preload you are going to need to run with the spring combo to know if you can block the upper spring. We will use the reasonable max of 3" of preload with this combo for an example along with your common 14" travel shock.

In order to calculate how much the springs are going to compress we need to know the maximum force/weight that the springs will see. To know that we need the primary spring rate, shock travel, and preload.

In our case will be using a 200/100 combo which has a primary rate of 66 lbs/in. The shock travel is 14". We will assume a worst case of 3" of preload.

Max force = 66 lbs/in * ( 14" shock travel + 3" preload )
Max force = 66 lbs/in * 17"
Max force = 1122lbs

Now it is going to get a little more tricky. EACH spring is seeing the same max force load.

The 200# spring is going to see 1122lbs
The 100# spring is going to see 1122lbs

Now we can calculate the displacement of each spring since we know each springs rate.

1122lbs/200 lbs/in = 5.61"
1122lbs/100 lbs/in = 11.22"

Note- 11.22" + 5.61" = 16.83" ( which is not exact but close to our 17" of compression because of my rounding :) )

Once we know how much each spring compresses at MAX compression of the shock we can figure out if the upper spring is going to block out before the shock gets to full compression.

If the lower 200# spring was 16" long to start and we compress it 5.61" it has a final length of 10.39"

If the upper 100" spring was 14" long to start and we compress it 11.22" it has s final length of 2.78"

Now we need to find the block height. Eibach makes this easy in their catalog here...

http://eibach.com/sites/devperformance-suspension.eibach.com/files/catalogs/ERS_19_US.pdf

We can look up a 2.5" dia x 14" long x 100# spring and see that the block height is 4.39". We know that the spring WANTS to be 2.78" long. That just won't work! We know that the block height is TALLER than the final length of the spring at max compression. We could have to lower the dual rate stop to a point where the upper spring can be no shorter than the block height of 4.39".

We then can subtract 2.78" from 4.39" and get 1.61". That 1.61" is roughly the distance before max shock compression that you will HAVE to engage the dual rate stop and transition from the primary to secondary rate. In our example this would be from 66lbs/in to 200lbs/in.

In our example you would have a spring rate of 66# from 0-12.39" of shock movement and 200# from 12.39-14". If the setup was designed to have 5" of shaft showing at ride height you would be able to have about 3.39" of bump/up-travel before you HAD to transition to the higher 200# rate.

The difference in rate of spring compression is one of the major reasons to keep the upper and lower spring within 100#'s of each other. You can see that in some cases even 100# difference will cause upper coil blocking.

Yikes, what a novel.....

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s

 

[csutton7]

#789 · May 14, 2015

ok, let me see if I can make sense of this in one brain cell. So if I'm going to use the 150 over 200's this is combo is equivalent to 83lbs per inch. Knowing I want 5" of shaft showing and 9" of shaft inside the shock body. So I take 1000/83 which equals 12 and the difference between 12-9=3, so 3" of preload.

So let's do a test run---let's use 200 over 200--this calcs out to 100lbs per inch--(200x200)/(200+200)=100, so 1000/100=10 10-9=1
1" of preload

is that correct???

ok now enlighten what's left of my one brain cell on stop nut location.....
Click to expand...

Yup, you got it. As combined spring rate goes up pre-load goes down.

That is why I gave you a spring rate window initially. You can't really go much stiffer than zero preload unless you use a triple rate. I don't suggest it because it makes the suspension feel like it is unloading for the last few inches of shock extension/droop. You can't go much more than about 3" of preload unless you REALLY watch the spring compression to prevent binding.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

Premium Member
Joined Jun 1, 2001
3,197 Posts
Discussion starter · #790 · May 14, 2015

WOW and thanks---I'll have to reread that a couple of times to decipher it, but that's great info to have, but better yet it's NEEDED info---

Mieser thanks again for all your help---

I so want to get my jeep together, but I have to wait until next week, but I think I'm going to order the other springs.

Now with that in mind there's a guy selling his "in house made 16" springs" for $70 delivered on ebay--a little risky, but he said he's had 100% success for 2 yrs---the only reason I bring this up is do I buy a pair 16" x 200's or just stick with QA1's in the 14" ---probably stick with the QA1's for now as it would allow me to buy the 20" led light also.

Coil Over Spring 1600 250 0200 16" x 2 5" x 200 lbs Sold Individually | eBay'

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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Mieser​

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Joined Jun 17, 2001
10,914 Posts
#791 · May 14, 2015 (Edited)

Mieser thanks again for all your help---

No problemo.

Don't know on the springs, its your money.

I do think having the 16" bottom springs would be nice to keep the slider a little higher up on the shock body. It could make getting the top nut on a little harder if the overall length is getting too long...

Your money.

You can always buy a 20" light bar later.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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FordFascist​

Ford Bigot
Joined May 26, 2004
3,849 Posts
#792 · May 14, 2015

I need to throw my CO cents in here, I think 150/200 is probably going to be a touch too much spring for that thing.

Have you weighed this thing yet? The 800 lbs/ corner weight on a Willy's type rig sounds awfully heavy. The trial and error coil spring can be frustrating. I would recommend putting the rig on proper scales to get the weight and then weighing as many of the components as possible. It's tedious as hell, but you can save yourself HOURS unloading your suspension, removing coil springs and dicking around with trying to put them back in by yourself.

I'm running 150/225 in the front of my FJ60 with a similar drivetrain selection and it's perfect so far - but I am running a much heavier rig than you. I have Longacre 4 tire scales and weighed my other truck with similar drivetrain to get me within 10% of my corner weight. Remember you want to deduct your unsprung weight from the total.

I know a PBB member in the area who has a shit ton of 16" coils because he doesn't believe in "measure twice, cut once". In fact his Wrangler has been in pieces for 6 years because of this. I think he has a few of what you seek.

 

[csutton7]

Discussion starter · #793 · May 14, 2015

Mieser--again thanks...

FF--to get the weights of the corners I did the ol' put the weight of the rig on my one of the coils--for instance 200lb coil in the front and it compressed the springs exactly 5" on both sides. For the rear it compressed the 150lb springs 6.5" on both sides---springs are Eibachs. With this method you are measuring sprung weight only. Seems pretty fool proof as long as you take exact measurements and I did.

Yea if your friend has some 16" x 200lb and if he had some 14" x 175lb or 200lb springs I'd be interested so let me know.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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csutton7​

Premium Member
Joined Jun 1, 2001
3,197 Posts
Discussion starter · #794 · May 14, 2015 (Edited)

some info--
12" stretch
frame is 2x4 x3/16"
motor 5.0 mustang
warn 9.5 winch
zf5-42 tranny
4spd atlas
¼" belly
body wrapped with 3/16" metal (not entire body, but from behind front fenders up to bottom of door height all around the back)
1 ¾ x .120dom cage
16 gallon fuel tank
40" spare

so the front calc'd out to 1000lbs and the rear 975lbs

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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MotoDave​

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Joined Jun 21, 2009
546 Posts
#795 · May 14, 2015

I need to throw my CO cents in here, I think 150/200 is probably going to be a touch too much spring for that thing.

Have you weighed this thing yet? The 800 lbs/ corner weight on a Willy's type rig sounds awfully heavy. The trial and error coil spring can be frustrating. I would recommend putting the rig on proper scales to get the weight and then weighing as many of the components as possible. It's tedious as hell, but you can save yourself HOURS unloading your suspension, removing coil springs and dicking around with trying to put them back in by yourself.

I'm running 150/225 in the front of my FJ60 with a similar drivetrain selection and it's perfect so far - but I am running a much heavier rig than you. I have Longacre 4 tire scales and weighed my other truck with similar drivetrain to get me within 10% of my corner weight. Remember you want to deduct your unsprung weight from the total.

I know a PBB member in the area who has a shit ton of 16" coils because he doesn't believe in "measure twice, cut once". In fact his Wrangler has been in pieces for 6 years because of this. I think he has a few of what you seek.
Click to expand...

Want to post up your info so we can actually compare? Shock travel, ride height, etc will all have an effect.

So far we know we're dealing with 4k lbs of sprung weight + axles/tires/etc ... Its not going to be a lightweight. Knowing your FJ's total weight, as well as sprung corner weights would make for a useful comparison.

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Mieser​

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Joined Jun 17, 2001
10,914 Posts
#796 · May 14, 2015 (Edited)

I need to throw my CO cents in here, I think 150/200 is probably going to be a touch too much spring for that thing.

Have you weighed this thing yet? The 800 lbs/ corner weight on a Willy's type rig sounds awfully heavy. The trial and error coil spring can be frustrating. I would recommend putting the rig on proper scales to get the weight and then weighing as many of the components as possible. It's tedious as hell, but you can save yourself HOURS unloading your suspension, removing coil springs and dicking around with trying to put them back in by yourself.

I'm running 150/225 in the front of my FJ60 with a similar drivetrain selection and it's perfect so far - but I am running a much heavier rig than you. I have Longacre 4 tire scales and weighed my other truck with similar drivetrain to get me within 10% of my corner weight. Remember you want to deduct your unsprung weight from the total.

I know a PBB member in the area who has a shit ton of 16" coils because he doesn't believe in "measure twice, cut once". In fact his Wrangler has been in pieces for 6 years because of this. I think he has a few of what you seek.
Click to expand...

For better or worse he had 200/110 and it was barely holding the front end up at a 71 lbs/in rate ( 1.5" uptravel ). I never heard how much preload he had, but 200/150 is really only an increase of 15 lbs/in? If he was at zero preload before with the 200/110 I wouldn't add 3.5" of preload on a 200/110 combo ( to get 5" of shaft ). The upper spring is going to be binding after maybe 2" of uptravel. Then you have a rate change to from 71# to 200#! Eeeeek!

Measuring how he did over the last few days should have given us very good sprung corners weights to work with.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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FordFascist​

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Joined May 26, 2004
3,849 Posts
#797 · May 14, 2015

Want to post up your info so we can actually compare? Shock travel, ride height, etc will all have an effect.

So far we know we're dealing with 4k lbs of sprung weight + axles/tires/etc ... Its not going to be a lightweight. Knowing your FJ's total weight, as well as sprung corner weights would make for a useful comparison.

Mine was 1000 (+/- 100) lbs per corner for a full bodied FJ with a nearly identical sprung drivetrain (unsprung is not consequential on this measurement).

14" CO's, 9" up, 5" down. I should have specified that I was running the same setup as csutton isofaras travel. I'm running 1.25" of preload.

For better or worse he had 200/110 and it was barely holding the front end up at a 71 lbs/in rate ( 1.5" uptravel ). I never heard how much preload he had, but 200/150 is really only an increase of 15 lbs/in? If he was at zero preload before with the 200/110 I wouldn't add 3.5" of preload on a 200/110 combo ( to get 5" of shaft ). The upper spring is going to be binding after maybe 2" of uptravel. Then you have a rate change to from 71# to 200#! Eeeeek!

Measuring how he did over the last few days should have given us very good sprung corners weights to work with.

I see how you guys are doing it and that works. I am not a trial and error person so I tend to go towards the hyper analytic side of things and get absolutely precise measurements in lieu of messing with it.

It sucks I took a dump earlier, now I'll never know if that roll would have caused me to crap my pants

Project Flat F***er (Fender)

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[csutton7]

#797 · May 14, 2015

Want to post up your info so we can actually compare? Shock travel, ride height, etc will all have an effect.

So far we know we're dealing with 4k lbs of sprung weight + axles/tires/etc ... Its not going to be a lightweight. Knowing your FJ's total weight, as well as sprung corner weights would make for a useful comparison.

Mine was 1000 (+/- 100) lbs per corner for a full bodied FJ with a nearly identical sprung drivetrain (unsprung is not consequential on this measurement).

14" CO's, 9" up, 5" down. I should have specified that I was running the same setup as csutton isofaras travel. I'm running 1.25" of preload.

For better or worse he had 200/110 and it was barely holding the front end up at a 71 lbs/in rate ( 1.5" uptravel ). I never heard how much preload he had, but 200/150 is really only an increase of 15 lbs/in? If he was at zero preload before with the 200/110 I wouldn't add 3.5" of preload on a 200/110 combo ( to get 5" of shaft ). The upper spring is going to be binding after maybe 2" of uptravel. Then you have a rate change to from 71# to 200#! Eeeeek!

Measuring how he did over the last few days should have given us very good sprung corners weights to work with.

I see how you guys are doing it and that works. I am not a trial and error person so I tend to go towards the hyper analytic side of things and get absolutely precise measurements in lieu of messing with it.

It sucks I took a dump earlier, now I'll never know if that roll would have caused me to crap my pants

Project Flat F***er (Fender)

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Mieser​

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10,914 Posts
#798 · May 14, 2015 (Edited)

Mine was 1000 (+/- 100) lbs per corner for a full bodied FJ with a nearly identical sprung drivetrain (unsprung is not consequential on this measurement).

14" CO's, 9" up, 5" down. I should have specified that I was running the same setup as csutton isofaras travel. I'm running 1.25" of preload.

Is that a SPRUNG or UNSPRUNG ,measured at 1000lbs per corner. Big difference.

I honestly think your full bodied FJ is probably lighter. csutton7 put a decent amount of metal in this thing.

I see how you guys are doing it and that works. I am not a trial and error person so I tend to go towards the hyper analytic side of things and get absolutely precise measurements in lieu of messing with it.

How are you going to get a more accurate measurement for SPRUNG weight? Even if you weigh all the unsprung parts you still need to add back approx 50% the weight of all the suspension links, driveshaft, etc. We could get really picky and say that the angle of the links and shaft also have an effect on how much of their weight is sprung vs unsprung. Lets also not forget that we need to take into account ANY angle in the mounting of the shock because that has an effect on motion ratio too.

Personally, I think using a known/published spring rate along with compression of the spring is pretty darn accurate.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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Mieser​

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Joined Jun 17, 2001
10,914 Posts
#799 · May 14, 2015

14" CO's, 9" up, 5" down.

Unless that is a typo, big difference.

csutton7 needs 5" uptravel, not 9"

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csutton7​

Premium Member
Joined Jun 1, 2001
3,197 Posts
Discussion starter · #800 · May 14, 2015 (Edited)

on the front the preload was 2" or more--I didn't measure it but I did look at it--remember I'm in construction and pretty much can tell the difference between measurements....with the 110's over 200's I had about 1.5" of shaft showing--

the rear had no preload, but it did have the triple rate(now removed) and it was compressed to coil bind was a spacer really--so if you add that the preload was closer to 3" I'd guess and I was on my bump stops with 100's over 150's....

I feel pretty comfortable with how I/we did the figures and based on Rckme52's weight of 4444lbs and I know I'm heavier I can't be to far off.

In a perfect world I'm going to run 200 over 200 in the rear and for the front 175/200 although 200 over 200 may win out--it will depend on what comes my way to buy or if I'm given springs....have a couple of feelers out....

I need to make a decision today, so I can order stuff and have it here early next week.....

 

[csutton7]

ok I'm going to buy the QA1 14" x 200's and run my EIBACH 150's over my EIBACH 200's in the front---

for the rear I'm going to run the QA1's 14" x 200 over the EIBACH 16" x 200's when they all show up next week---

If I don't like the front setup I can change the 150's out for 175's. I'm not out anything at this time and if they work then fine I can be patient and try and find some 16" x 200 to swap the lowers since I would prefer to run a 16" x 200 vs 14" x 200 on the bottom. This would also allow me to run 200 over 200 if needed for the front although 175's may be preferrable, again I can put them in the trade thread and just wait or sell them and buy 175's if needed.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
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csutton7​

Premium Member
Joined Jun 1, 2001
3,197 Posts
Discussion starter · #802 · May 14, 2015 (Edited)

ok Mieser let's see if I can figure out the stop nut setting with 150 over 200:

we know we 85.7lbs per inch and from you telling me the preload should be 3" with this set up we add 3" to 14" which = 17

85.7 x 17=1457

1457/150=9.7
1457/200=7.3

9.7 + 7.3= 17 so I'm still on track with you

Block height of 14" x 150 coil is 4.72"
Block height of 14" x 200 coil is 4.92"

200lb spring 14"-7.3"=6.7"
150lb spring 14"-9.7"=4.3"

4.3" is less than the block height of 4.92"

4.9-4.3=.6

so roughly 5- .6= 4.4", but above what or from what is what I don't understand??

on another note my buddy is giving me some 185lb Pac springs which I'll pick up either Friday night or Saturday morning.:D of course I've already installed the 150's over the 200's on the front, but now I'm trying to understand where you set the stop nuts so I can get them close.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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rckme52​

Premium Member
Joined Jul 7, 2002
718 Posts
#803 · May 15, 2015

Secondary stops.



They can be a tuning tool. It is nice NOT to HAVE to use them to prevent blocking out the typically softer upper coil. When the dual rate slider hits the rate stop you are changing the spring rate.



Spring rate = ( lower spring rate * upper spring rate)/(lower spring rate + upper spring rate)



The secondary rate is JUST the spring rate of the lower coil once the slider hits the stop.



In example if your running a 200/200 spring combo your combined spring rate is 100 lbs/in. (200*200)/(200+200)= 100. Your spring rate will be 100 lbs/in till the slider touches the stop. Then the spring rate will go to 200 lbs/in.



You are basically doubling the spring rate at a minimum once the slider hits the stop. As the upper and lower spring rates get further apart so does the transition between the primary and secondary rate. If you where running a 200/100 combo you would have a primary rate of 66 lbs/in while you would still have a 200 lbs/in secondary rate.



The only reason to HAVE to worry about the dual rate slider is when you might have a rate difference so great between the upper and lower springs that you risk blocking the upper spring before full compression. Different rate springs compress at different rates :)



We can use the case of a 200/100 spring combo. The lower being a 16"x200 and the upper being a 14"x100.



You need to know how much preload you are going to need to run with the spring combo to know if you can block the upper spring. We will use the reasonable max of 3" of preload with this combo for an example along with your common 14" travel shock.



In order to calculate how much the springs are going to compress we need to know the maximum force/weight that the springs will see. To know that we need the primary spring rate, shock travel, and preload.



In our case will be using a 200/100 combo which has a primary rate of 66 lbs/in. The shock travel is 14". We will assume a worst case of 3" of preload.



Max force = 66 lbs/in * ( 14" shock travel + 3" preload )

Max force = 66 lbs/in * 17"

Max force = 1122lbs



Now it is going to get a little more tricky. EACH spring is seeing the same max force load.



The 200# spring is going to see 1122lbs

The 100# spring is going to see 1122lbs



Now we can calculate the displacement of each spring since we know each springs rate.



1122lbs/200 lbs/in = 5.61"

1122lbs/100 lbs/in = 11.22"



Note- 11.22" + 5.61" = 16.83" ( which is not exact but close to our 17" of compression because of my rounding :) )



Once we know how much each spring compresses at MAX compression of the shock we can figure out if the upper spring is going to block out before the shock gets to full compression.



If the lower 200# spring was 16" long to start and we compress it 5.61" it has a final length of 10.39"



If the upper 100" spring was 14" long to start and we compress it 11.22" it has s final length of 2.78"



Now we need to find the block height. Eibach makes this easy in their catalog here...



http://eibach.com/sites/devperformance-suspension.eibach.com/files/catalogs/ERS_19_US.pdf



We can look up a 2.5" dia x 14" long x 100# spring and see that the block height is 4.39". We know that the spring WANTS to be 2.78" long. That just won't work! We know that the block height is TALLER than the final length of the spring at max compression. We could have to lower the dual rate stop to a point where the upper spring can be no shorter than the block height of 4.39".



We then can subtract 2.78" from 4.39" and get 1.61". That 1.61" is roughly the distance before max shock compression that you will HAVE to engage the dual rate stop and transition from the primary to secondary rate. In our example this would be from 66lbs/in to 200lbs/in.



In our example you would have a spring rate of 66# from 0-12.39" of shock movement and 200# from 12.39-14". If the setup was designed to have 5" of shaft showing at ride height you would be able to have about 3.39" of bump/up-travel before you HAD to transition to the higher 200# rate.



The difference in rate of spring compression is one of the major reasons to keep the upper and lower spring within 100#'s of each other. You can see that in some cases even 100# difference will cause upper coil blocking.



Yikes, what a novel.....
Click to expand...

Smarty pants ;)



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csutton7​

Premium Member
Joined Jun 1, 2001
3,197 Posts
Discussion starter · #804 · May 15, 2015

OK been trying to dial in the front to the ride height, but wow talk about fun--I need to use the stops to get it to sit at ride height, so dialing those in to exactness is not treating me kindly, but I'll get there--of course I'll be redoing it since I'll be putting the 185lbers on, but it's good practice and will help me learn how the math relates to real life.....

--my '48 build: not a build thread, but kind of is--just tryin to help...

 

[csutton7]

#805 · May 15, 2015

ok Mieser let's see if I can figure out the stop nut setting with 150 over 200:

we know we 85.7lbs per inch and from you telling me the preload should be 3" with this set up we add 3" to 14" which = 17

85.7 x 17=1457

1457/150=9.7
1457/200=7.3

9.7 + 7.3= 17 so I'm still on track with you

Block height of 14" x 150 coil is 4.72"
Block height of 14" x 200 coil is 4.92"

200lb spring 14"-7.3"=6.7"
150lb spring 14"-9.7"=4.3"

4.3" is less than the block height of 4.92"

4.9-4.3=.6

so roughly 5- .6= 4.4", but above what or from what is what I don't understand??

on another note my buddy is giving me some 185lb Pac springs which I'll pick up either Friday night or Saturday morning.:D of course I've already installed the 150's over the 200's on the front, but now I'm trying to understand where you set the stop nuts so I can get them close.
Click to expand...

All that looks right.

You know the block height of the spring is 4.9"( call it 5")

From the bottom of the final position of the top nut ( once you dial in all the preload you need ) you need to position the dual rate stop so that the dual rate slider does not allow the upper spring to be shorter than 5".

The walls of text are getting to me....needs more pictures....



That is the MINIMUM point ( highest up on the shock ) that you can put the dual rate stop to keep from binding the upper coil at full compression.

You may want to move the dual rate stop down to transfer to the secondary rate ( the rate of the single lower spring ) sooner. It isn't required, but it is another tuning tool.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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Mieser​

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#806 · May 15, 2015

OK been trying to dial in the front to the ride height, but wow talk about fun--I need to use the stops to get it to sit at ride height, so dialing those in to exactness is not treating me kindly, but I'll get there--of course I'll be redoing it since I'll be putting the 185lbers on, but it's good practice and will help me learn how the math relates to real life.....

Why are you using the 'stops' to get it to ride height? I assume you are talking about the dual rate stops?

You should be lowering the top nut to add preload to dial in your ride height. Do you have the top nut down a full 3" from the FREE length of the spring stack up?
(ie compression on the springs when the shock is FULLY extended )

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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3,197 Posts
Discussion starter · #807 · May 15, 2015

~~!!!

I set the top nut 3" down from the top(or highest point on the shock that it will screw to)....springs totally relaxed

and since you earlier said no more than 3" of preload I'm not moving it. are you saying I can move it(let's come back to that)?

from there I've was moving the secondary stop nuts to try and get to the final ride height, because I didn't know where to measure from to set the secondary stops. it was trial and error. I could find anything on the internet where to measure from, but I didn't search long. I was getting closer by working my way to get close to your drawing(DRAWING is PERFECT, so THANKS again), but I wasn't measuring to slider section in your drawing but to the nuts!!!! so again thanks!!!!

so you set the preload, but I got the feeling you never touched that if you were set at 3" preload, unless you are reducing preload or if you had to go from like 2" to 2.5", but don't go past 3" preload.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
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Mieser​

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#808 · May 15, 2015 (Edited)

I set the top nut 3" down from the top(or highest point on the shock that it will screw to)....springs totally relaxed

and since you earlier said no more than 3" of preload I'm not moving it. are you saying I can move it(let's come back to that)?

from there I've was moving the secondary stop nuts to try and get to the final ride height, because I didn't know where to measure from to set the secondary stops. it was trial and error. I could find anything on the internet where to measure from, but I didn't search long. I was getting closer by working my way to get close to your drawing(DRAWING is PERFECT, so THANKS again), but I wasn't measuring to slider section in your drawing but to the nuts!!!! so again thanks!!!!

so you set the preload, but I got the feeling you never touched that if you were set at 3" preload, unless you are reducing preload or if you had to go from like 2" to 2.5", but don't go past 3" preload.
Click to expand...

I think we need to define preload....

If you are using two 14" springs the total free height of the springs should be 28" PLUS about 1/2" for the dual rate slider. That is 28.5" tall total resting.

With the shock fully extended....

ZERO preload would be if you ran the top nut down till it touched the top of the springs. The bottom of the top nut would be approx 28.5" away from the bottom spring eye cup ( where the bottom spring is resting )

To add more 'preload' we need to run the top nut down further...this will be compressing the springs while the shock is fully extended.

Generally, about 3" of preload is a good 'max' but you can add more as long as you don't block out BOTH springs before the shock fully compresses.

Preload really doesn't have anything to do with the nuts position relative to the top of the shock or shock threads.....its about spring height.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s

 

[csutton7]

Discussion starter · #809 · May 15, 2015

sorry for the confusion--yea it was from top of relaxed springs which had the nut at the top(maybe it wasn't exactly touching but it was resting on the relaxed springs)---actual measurement with slider is more like 28.625 or 28.6875 , because I was checking things to make sure I didn't screw something up that's why I know that measurement--it was a tad shy of 28¾"!!!!

So I know I'm good on the preload cuz they're at 25.625" or so....

ok so I can dial in more if needed---I may, but we shall see--I may be picking up the 185lb springs, so the 150's are coming off---

I may see what happens on the rear with 150's over the 200's if the delivery happens today as per tracking # of the QA1, but my oldest son may have to open the door and sometimes it seems things like this just slip thru the cracks.

thanks again for all your help--again how you are so well versed in all this is impressive...thanks for being on our TEAM!!! on me when we meet on the trail!!!

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
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Mieser​

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#810 · May 15, 2015

thanks again for all your help--again how you are so well versed in all this is impressive...thanks for being on our TEAM!!! on me when we meet on the trail!!!

No problem, happy to help.

How much shaft did you have showing with the 3" of preload? I'm curious if it is close to what we predicted. The springs where used(?) so they could be a little light since they are broken in.

You can dial in more than 3" of preload, but you need to run the max compression numbers again to see if you will block BOTH springs before the shock is fully compressed. We know the top spring blocks about .6" before max compression already.

You need to figure out if the block height of both springs (plus the dual rate slider gap) is longer than the distance from the top nut to the bottom of the shock body.

The 185 upper should make this better. It will be less likely to block the upper spring because the rate difference from the top to the bottom is less. You will have a 96 lbs/in rate instead of a 86 lbs/in. That will either let you back the preload off and/or let you have more shaft showing.

Just be aware....

Springs are the smaller part of how the suspension will be working vs valving. To take full advantage of your nice shocks you will need to tune them....and maybe with professional help. Don't expect miracles just yet.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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3,197 Posts
Discussion starter · #811 · May 15, 2015

3-4" max--it's hard to tell cuz the body can recess down into the bottom cup. I need to find a smaller tape measure to get inside the spring to measure accurately. one more thing is I have the secondary stops set in the wrong place, so that's affecting things also. tonight I'll play some more and tomorrow also and will report back.

I just want to get to ride height to get started!!! Valving can come down the road after some driving.

thanks again...

got some math to do on 185 over 200's.....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
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Mieser​

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#812 · May 15, 2015

3-4" max--it's hard to tell cuz the body can recess down into the bottom cup. I need to find a smaller tape measure to get inside the spring to measure accurately. one more thing is I have the secondary stops set in the wrong place, so that's affecting things also. tonight I'll play some more and tomorrow also and will report back.

I just want to get to ride height to get started!!! Valving can come down the road after some driving.

thanks again...

got some math to do on 185 over 200's.....

Make sure you take into account that the shock body can recess down into the lower cup when you calculate things.

I did notice a small error in this...

ok Mieser let's see if I can figure out the stop nut setting with 150 over 200:

we know we 85.7lbs per inch and from you telling me the preload should be 3" with this set up we add 3" to 14" which = 17

85.7 x 17=1457

1457/150=9.7
1457/200=7.3

9.7 + 7.3= 17 so I'm still on track with you

Block height of 14" x 150 coil is 4.72"
Block height of 14" x 200 coil is 4.92"

200lb spring 14"-7.3"=6.7"
150lb spring 14"-9.7"=4.3"

4.3" is less than the block height of 4.92"

You are worried about the lighter UPPER coil blocking out. You used the block number for the lower coil. They are close enough it doesn't matter too much, but it actually makes things a little better. You could get away without lowering the dual rate stop at much.

Now....

Rough numbers you need to have 4.92+4.72+.625(dual rate space)=10.265" of space from the bottom of the top nut to the lower coil seat when the shock is fully compressed ( to keep from blocking the springs )

You should be able to back calculate roughly how much your MAX preload would be using that number. If you have more than 10.265" of space you could add some more preload ( over the 3" you are using now ).

Next time you have the shocks out/apart measure everything and make a decent drawing. It would be nice to know how much room you have to work with.

42 MB, 225, T18, big kid go cart with clown tires

 

[csutton7]

Discussion starter · #813 · May 15, 2015

thanks--I thought I had changed that number cuz I saw it too, but maybe I had it right but my mind went left and I changed it to the wrong one!!!

I have the rear shocks hanging so I can take great measurements from eye to eye and elsewhere and make a drawing.

Thanks for the added tidbit about adding those block height numbers together to do a check, that makes life a bit easier.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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csutton7​

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Discussion starter · #814 · May 17, 2015 (Edited)

got it sitting at ride height and I've got ¼"-5/16" clearance to get in the garage---

at the moment 185's over 200 on the front and 150 over 200 on the rear as I wait for the other 200's to show up....

she certainly seems to be flexy driving it on the road and it's nice to be not smacking the bump stops constantly!! :D

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Mykul​

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#815 · May 18, 2015

Your willys looks mean! look'n like it wants to eat some rocks!

THe Sierra Nevada Mountains are my Sanctuary!!!
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Mieser​

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#816 · May 18, 2015

got it sitting at ride height and I've got ¼"-5/16" clearance to get in the garage---

at the moment 185's over 200 on the front and 150 over 200 on the rear as I wait for the other 200's to show up....

she certainly seems to be flexy driving it on the road and it's nice to be not smacking the bump stops constantly!! :D

Good to see you making progress. How much preload did you end up using?

The sway will have to be something that you work on tuning. We don't have any idea how the shocks are valved. Suspension geometry also has a huge part to play. You can run the dual rate stop down slightly to help with roll but then you have to deal with the step up spring rate. There is also a reason you see sway-bars on pretty much every single OEM street driven modern vehicle. It is difficult to have a nice soft ride and still have limited sway.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s
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csutton7​

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Discussion starter · #817 · May 18, 2015

PRELOAD-- i don't recall exact #'s --but passenger was like ½" to ¾" & driver was 1½" ---i'll measure them again tonight---rear was 3" to start, but now I can't recall if we adjusted them or not--was lot's of adjusting going on...

secondary stop nuts are set right now to engage ¼" before total top spring compression....

sway bars have been on my mind for sometime---just need money--although I do have the rear sway bar off my dodge that I may try and adapt to the rear, but we shall see--Anti-Rocks will be the preferred, but again money needs to be in the coffers first....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
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TimCubed​

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#818 · May 18, 2015

I have a sway bar on the rear of mine, I got curious one day on the trail and disconnected one side to see how it reacted with out it, I went maybe 1/2 mile and hooked it back up. My suspension just wanted to unload and got just way too tippy. One other thing, the sway bar will affect your articulation. I took a 150 upper out and put in a 100, I wish I had went with a 125. My rear compression is a little soft but articulation is great. So now you have to get it on the trail and you may have to fine tune it a bit. I traded springs a couple times to get mine better. This year on the Dusy if I haul my trailer I may put the 150 back in, maybe Rodney will drag his trailer and I won't have to drag mine.

Dusy!.....September, put it on your calendar! No date yet.

'44 GPW Stretched and Linked
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csutton7​

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Discussion starter · #819 · May 18, 2015

Tim--what are you running for sway bars?

SHOCK INFO: that i can recall:

eye to eye 35.5" when shocks are fully extended--measured this when I removed the fronts completely and turned them around to get better access to the schraeder valve.

clearance from bottom of top nut(when threaded as far as it will go to the top of the shock) to the top of the upper spring when springs are installed with slider on extended shock:

front 1 ¾"

rear 1 ⅞"

preload added to the measurements above---I was shooting for 1" preload on the front and 3" on the rear. I know the passenger was less than 1"--either ⅝" or ¾" and the driver side I just don't recall now.

Problem: when setting up ride height I was having a hell of time dialing in the front. I had the back jacked up and it wasn't level. Finally after standing back and looking at things and scratching my head wondering WTF is going on I thought that maybe I was loading the front end and with the rear passenger side sitting higher on my temp blocks than the rear driver side. Was I was loading the front driver side more because of the jeep not sitting level?? So I then decided to put the 150's over the 200's on the rear and dial them in and when I did that I was able to dial the front end. So make sure your rig is sitting somewhat level when installing and adjusting your coil overs!!!

Rear preload started at 3", but now I don't recall where we ended up setting them.

All secondary stops are set ¼" before top spring is totally compressed, for right now. I'm still not quite sure about the math on how you set them. I just need to reread it again as I understand part of it. But Mieser gave an example of one set of numbers, some of my numbers don't require subtraction, so I'm not sure what to do about that?? I'll give an example later and we can rehash this more.

 

[csutton7]

#820 · May 18, 2015

All secondary stops are set ¼" before top spring is totally compressed, for right now. I'm still not quite sure about the math on how you set them. I just need to reread it again as I understand part of it. But Mieser gave an example of one set of numbers, some of my numbers don't require subtraction, so I'm not sure what to do about that?? I'll give an example later and we can rehash this more.

Generally, the closer the upper and lower spring are in rate, the less chance you have of blocking the upper spring before the shock is fully compressed.

I usually notice that you are 'forced' to lower the dual rate stop nut when the upper and lower springs are starting to be about 75-100# apart in rate.

It's good to run the math just to make sure. It is also worth double checking that both compressed springs can fit on the shock body when fully compressed, especially if you are over 3" of preload.

42 MB, 225, T18, big kid go cart with clown tires
92 Dodge W250 daily driver on 39s

#821 · May 18, 2015 (Edited)

Another 'tuning' suggestion - keep a notebook/logbook just for suspension and write EVERYTHING down.

What springs you're using, How much preload, where you set the slider stop, etc.

When you make any change, write everything down again with a note about WHY you made the change.

Coilovers are neat because you can fine-tune everything about them for your specific truck, but that's also their downside. Don't expect this to be the last set of springs you ever have to buy, and don't expect the stock valving to work for your vehicle weight, spring rates, driving style, etc. In my opinion if you're going to run a 'custom' setup, you have to put the time into tuning otherwise it'll probably never work all that well for your specific setup.

Anyways not to be a downer, truck is looking good sitting on all 4's, and you're making good progress.

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csutton7​

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Discussion starter · #822 · May 18, 2015 (Edited)

Mieser---yea that's is smart to check, thanks---I'll have to double check the rear with the 16" springs, but I'm pretty sure there's no issue when I briefly looked at the compressed dimension....

MD--thanks and another smart thing to do--I did write down the original set up, but I need to update it now since I changed it some....thanks again....

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

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csutton7​

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3,197 Posts
Discussion starter · #823 · May 18, 2015

Thanks to Mieser for this link:

http://eibach.com/sites/devperformance-suspension.eibach.com/files/catalogs/ERS_19_US.pdf

FRONT block heights
14" x 185=4.76"
14" x 200=4.92"
slider= .625"
total= 10.3"

REAR block heights(current)
14" x 150=4.72"
14" x 200=4.92"
slider= .625"
total= 10.265"

REAR--new block heights
14" x 200= 4.92"
16" x 200= 5.89"
slider= .625"
total= 11.435"

one more key item is the shaft has ⅞" hidden in the lower cup, so I took that into account to get my ride height to the desired spot.

--my '48 build: not a build thread, but kind of is--just tryin to help...
'56 truck:
'56 Willys truck

 

[csutton7]

Discussion starter · #826 · May 19, 2015

Here's my measurements for preload--you will have to subtract 1 ¾" from the front measurements & 1 ⅞" from the rear measurements to get the true preload. Why do you have to do this? Because the 14" springs when sitting on the 14" coil over shocks fully extended don't reach the top nut, so I measured this distance to know how far I had to screw the top nut down to start the preload. From there it was adjusting the top nut needed to reach my required ride height. (NOTE: I will be changing the rear springs to 14" X 200 over 16" x 200 and will add the new #'s to below).

front weight on springs is 1000lbs
rear weight on springs is 975lbs

front driver: 2 ¾" - 1 ¾" = 1" preload on 185 over 200
front passenger: 2 ⅜" - 1 ¾" = ⅝" preload on 185 over 200
rear driver: 3 ½" - 1 ⅞" = 1 ⅝ preload on 150 over 200
rear passenger: 3 7/16" - 1 ⅞" = 1 9/16" preload on 150 over 200

I achieved my ride height with this set up, but as of yet there's been no trail time so things may change. So stay tuned.

Secondary stop nuts I haven't set to final placement as of yet, but I did set them so that upper spring would stop compressing ¼" from it's block height(total compressed height) for now. Again need to get some road and trail time to work on final set point.

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TimCubed​

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#827 · May 19, 2015

Is your rig empty, or do you have gas in the tank, tools, and trail gear aprox. trail weight?

'44 GPW Stretched and Linked
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csutton7​

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Discussion starter · #828 · May 19, 2015 (Edited)

tank is ¾ full or close to it--some tools--recovery straps and such, but not the essential tool kit that needs to be put together, nor extra fluids--thus why I'm going to 200 over 200 on the springs, cuz it's going to get heavier in the back for sure.

I have one of those baskets that fits into an upper receiver hitch I added off the tire carrier--that will/can carry stuff too if needed....

I need to work on putting together the travel kit here pretty quick!!!!

--my '48 build: not a build thread, but kind of is--just tryin to help...