Definitive(hopefully) 80's spring selection thread (1 Viewer)

[Qball]

So I'm going to install my 3rd set of springs(4th counting stock) and I am still struggling on finding the right springs for my needs. We have information scattered all over the place but very difficult to reference. So I am hoping to create a repository of technical informations so selecting springs for the 80s would be a breeze.....hopefully.

Key information are vehicle weight per axle and spring rate and how they can be pairs together. For example I went to truck stop and found out my front axle is currently at 2950lbs and rear axle is at 3100lbs. So what spring/spring rate should I use? I can't find any information on this so hopefully I can create a table of that here for reference. So hopefully once we find out how much per axle weight is and we can easily select the right spring rate and height. This should take out any guess work needed for selecting springs previously.

To get the "right" spring for the weight we need to find where ideal sag is. shocks is our travel limiting factor so it dawned on me that we should use our shock to measure where we our static sag is at. Most 0-3 inch 80's dampers are about 10 and 9 inches of full travel front and rear respectively, 4-6 inches lift dampers are about 11 and 10 inches of full travel front and rear respectively. This means if I want 6 inches of sag on 10 inch travel shocks I should have 4 inches of travel/shock shaft left on the shock.

To sum it up the ideal spring for an 80 is the one that provides static sag of ~30-40% of suspension(shock) travel and below 3 data reference points will help us get there:
1. Spring rate
2. Vehicle weight/per axle weight
3. Shock/suspension length

We need about about 5-6 inches of shock shaft exposed for 0-3 inch lift shocks and 6-7 inches of shaft exposed for 4-6 inch lift shocks. More shock shaft exposed means the springs are too stiff and losing droop and too little means the springs are over laden.


Please help contribute to the thread and I'll add them to the top so it can be easily searched.

Reference table:

Front axle weight------Ideal spring rate(standard overland use case)
2500-2700lbs----------220lbf/in ?????
2700-2900lbs
2900-3100lbs
3100-3300lbs


Rear axle weight-------Ideal spring rate
2500-2700lbs----------250lbf/in ?????
2700-2900lbs
2900-3100lbs
3100-3300lbs

 

[Qball]

Spring rates per manufacture(lbf/inch):

----------------------------------------------------------------------
For reference...
Stock front: 160
Stock rear: 170
----------------------------------------------------------------------


----------------------------------------------------------------------
SLEE front:
Model--------rate-----lift
SOF4FM(need info, slee claims 250lb extra weight in the front)
SOF5FM(need info, slee claims 250lb extra weight in the front)

SLEE rear:
Model--------rate-----lift
SOF4RM(need info, slee claims 400lb extra weight in the rear)
SOF4RHP
SOF5RM(need info, slee claims 400lb extra weight in the rear)
SOF5RH
----------------------------------------------------------------------


----------------------------------------------------------------------
OME front:
Model--------rate-----lift
OME 2861---170/220-----stock height (.25-.75)
OME 2851---220-----light to medium load (2-2.5 inch)
OME 2850---220-----heavy load (2-2.5 inch)
OME 2850J--220-----heavy load (3.5 inch)
OME 2418---300-----Comp heavy load (3 inch)
OME 2419---300-----Comp heavy load (4 inch)
OME 2420---300-----Comp heavy load (5 inch)

OME rear:
Model--------rate-----lift
OME 2862---170/220-----stock height (.25-.75)
OME 2860---220-----light to medium load (2-2.5 inch)
OME 2863---250-----heavy load (2-2.5 inch)
OME 2864---320-----extra heavy load (2-2.5 inch)
OME 2863J--250-----heavy load (3.5 inch)
OME 2421---280-----Comp heavy load (3 inch)
OME 2422---280-----Comp heavy load (4 inch)
OME 2423---280-----Comp heavy load (5 inch)
----------------------------------------------------------------------



----------------------------------------------------------------------
TJM front:
Model-----------rate-----lift
770FR80C------NA------Progressive 50mm(2 inch)
770FRC380B---300-----Comfort 3 inch

TJM rear:
Model-----------rate-----lift
770RR80C------NA------Progressive 50mm(2 inch)
770RRC380B---280-----Comfort 3 inch
----------------------------------------------------------------------


Ironman front:

Ironman rear:

 

[Qball]

Sample weight and spring combinations:


Qball sample 1:
Weight: Bone stock without third row seats (~5200lbs)
Springs: OME stock height springs (170/220)
Impression: Very stiff ride or jarring but handles great. But with 200-300lbs it smoothes out a lot.

Qball sample 2:
Weight: Bone stock without third row seats (~5400lbs)
Springs: TJM 50mm progressive springs
Impression: Lexus smooth, fantastic on and off road!

Qball sample 3:
Weight: 6100 (3000 F & 3100 R)
Springs: TJM 50mm progressive springs
SAG: Axle to fender 22.75 and 22 inches front and rear respectively. Exposed shock shaft is about 6 and 5 inch front and rear respectively.
Impression: Smooth but lots of body role and the rear sags. Blows through travel too much when offroading.

Qball sample 4:
Weight : 6100 (3000 F & 3100 R)
Springs: OME 2.5 heavies
SAG: 23 and 24 front and rear axle to fender.
Impression: still very smooth but definitely noticeably firmer but not as firm as expected from heavy. Not harsh at all and body role is reduced, think my fox shocks are giving up the ghost though. I think 1 inch high in the rear is the perfect for the 80.


@LandCruiserPhil rig:
Weight: 6950lbs
Springs: OME 850J+10mm packer/863J
Sag: 23" hub to fender
Impression: Smooth on and off of the road

 

[Qball]

Also helpful would be weight with how much lift(hub to fender or bump stop gap) is gained for the springs installed per axle

 

[Qball]

Bump, no interest? I think this could really help everyone when comes to selecting correct springs.


Does anyone have more detailed specs on slee, dobison, tjm and ironman springs? So far I have not been able to find spring rate except for OME

 

[LandCruiserPhil]

Bump, no interest? I think this could really help everyone when comes to selecting correct springs.


Does anyone have more detailed specs on slee, dobison, tjm and ironman springs? So far I have not been able to find spring rate except for OME

Contacting Slee, Dobison, TJM and Ironman would be your most accurate source of information and most believable.

 

[Qball]

Contacting Slee, Dobison, TJM and Ironman would be your most accurate source of information and most believable.

Yeah I was hoping people here who might have the info can contribute. When I find some time I'll do that.

 

[nuclearlemon]

I can do a couple different measurements soon. Can get you slinky "heavy" on a 7k plus rig and slee 4" heavy on same rig when i put the slees back on . Ill get slinky this weekend if i remember. Might be a week or so before i get the slees back on.

Reasoning....apparently thw aussie version of really heavy and the us version are different. Slinkys ride fn phenomenal off road, but in road are downright scary and you get bad concrete bucking (ask anyone with a long wheelbase pick up if you dont know what that is).

 

[baldilocks]

Contacting Slee, Dobison, TJM and Ironman would be your most accurate source of information and most believable.

This seems to double top secret info that is disseminated on a need to know basis and apparently we don’t need to know.

Besides, swapping springs over and over until you get what you want is fun, educational and a lot like exercise.

IMO, OME 863 “heavies”, at 250lbs/inch, are not heavies at all unless your version of a heavy load is a weekend cooler, tent and two sleeping bags. The OME comp rears, at 280lb/inch, are getting there but still feel willowy and lack confidence on very tough trails when loaded with, say, 500-600 pounds. This, of course, is after adding a full compliment of armor and your rig weighing around 5800# empty.

I have settled into the 4” Slee heavy progressive coils in the rear. Their stats are top secret but we do know they were made by Dobinson. They must be over 300lbs/inch (spring material measures 22mm thick) but the fact that they are progressive or dual rate helps the ride while unloaded and also allows greater down travel and uses more of the shock. They lift my 5800# rig more like 5” so when I load up whatever I want, I still have 4” of lift or so. We can’t have our cake and eat it too but a dual rate or progressive spring sure does come a lot closer than a single rate spring.

I run the new Dobinson tapered coils up front. They come in a 3” lift and, iirc, I was told by the rep that they are like 170/274lbs/inch and are a dual rate coil. They ride nice and dreamy compared to the single rate coils I have had before which consist of slee 4”, 863j, and OME comp 5” which are 300lbs/inch rate; way to stiff unless your front bumper weighs 400 pounds or you drop a 6bt into the engine bay. My 2 cents.

 

[Qball]

This seems to double top secret info that is disseminated on a need to know basis and apparently we don’t need to know.

Besides, swapping springs over and over until you get what you want is fun, educational and a lot like exercise.

IMO, OME 863 “heavies”, at 250lbs/inch, are not heavies at all unless your version of a heavy load is a weekend cooler, tent and two sleeping bags. The OME comp rears, at 280lb/inch, are getting there but still feel willowy and lack confidence on very tough trails when loaded with, say, 500-600 pounds. This, of course, is after adding a full compliment of armor and your rig weighing around 5800# empty.

I have settled into the 4” Slee heavy progressive coils in the rear. Their stats are top secret but we do know they were made by Dobinson. They must be over 300lbs/inch (spring material measures 22mm thick) but the fact that they are progressive or dual rate helps the ride while unloaded and also allows greater down travel and uses more of the shock. They lift my 5800# rig more like 5” so when I load up whatever I want, I still have 4” of lift or so. We can’t have our cake and eat it too but a dual rate or progressive spring sure does come a lot closer than a single rate spring.

I run the new Dobinson tapered coils up front. They come in a 3” lift and, iirc, I was told by the rep that they are like 170/274lbs/inch and are a dual rate coil. They ride nice and dreamy compared to the single rate coils I have had before which consist of slee 4”, 863j, and OME comp 5” which are 300lbs/inch rate; way to stiff unless your front bumper weighs 400 pounds or you drop a 6bt into the engine bay. My 2 cents.

This is some really good info!!!

Hope my OME heavies ride ok or I'll have to swap again and get some excercise.....again.


My front is 2800lbs hope the heavies at 250lbs will be ok.

 

[Qball]

I can do a couple different measurements soon. Can get you slinky "heavy" on a 7k plus rig and slee 4" heavy on same rig when i put the slees back on . Ill get slinky this weekend if i remember. Might be a week or so before i get the slees back on.

Reasoning....apparently thw aussie version of really heavy and the us version are different. Slinkys ride fn phenomenal off road, but in road are downright scary and you get bad concrete bucking (ask anyone with a long wheelbase pick up if you dont know what that is).

Thanks, those will be very good data points!

 

[Dragos80]

Dobinson does not want to give out any info, because they claim the spring rate is proprietary information and we are not supposed to know what it is, just trust them they are good for us.

How the hell is one supposed to compare coils from different manufacturers if no info is provided?

If I want to compare a Civic vs a Corolla I can look at the horsepower, torque, MPG, engine cc, number of gears in their transmission box, etc.

Dobinson spring coils were made by God himself.

 

[ewillis]

Dobinson does not want to give out any info, because they claim the spring rate is proprietary information and we are not supposed to know what it is, just trust them they are good for us.

How the hell is one supposed to compare coils from different manufacturers if no info is provided?

If I want to compare a Civic vs a Corolla I can look at the horsepower, torque, MPG, engine cc, number of gears in their transmission box, etc.

Dobinson spring coils were made by God himself.

The mystery makes me want them more!

 

[Dragos80]

The mystery makes me want them more!

You can always add spacers if they sag, right?

Oh, and that color screams "buy me". Am I right or what?

 

[baldilocks]

Dobinson does not want to give out any info, because they claim the spring rate is proprietary information and we are not supposed to know what it is, just trust them they are good for us.

How the hell is one supposed to compare coils from different manufacturers if no info is provided?

If I want to compare a Civic vs a Corolla I can look at the horsepower, torque, MPG, engine cc, number of gears in their transmission box, etc.

Dobinson spring coils were made by God himself.

When I bought Dobinson coils from David Otero last spring, he was not reluctant to answer all of my questions. Most people would be unable to choose the correct spring if they were armed with all the info in the world and lacked lots of experience and empirical data because "The only source of knowledge is experience".

 

[LandCruiserPhil]

...................... Most people would be unable to choose the correct spring if they were armed with all the info in the world and lacked lots of experience and empirical data because "The only source of knowledge is experience".

▲THIS▲

 

[Dragos80]

Since I don't drive anyone else's car and their experience does not help me in setting up my car to fit my driving style, I cannot rely on anyone's input.

I like to have a firm ride. Sports car like ride. I don't care about a plush ride, able to absorb bumps. I want it to be able to corner the way I want to, evasive maneuvers should not be a near death experience.

Soooooo, I want some stiff springs. Now, I need to know what the damn compression rate is on those Holy Springs.
Should I go with Slinky? OME? or others?

Yes, the shocks make a huge difference too, I also like them HD.

And, no I don't carry any weight. I took out the 3rd row, took out the spare tire mechanism from under the car, to make up for the added weight I got on my custom made rear bumper with a spare tire holder on it and the ARB up front.

Some people would have their kidneys fall out driving my car, but it is my car and I want it in a particular way.

Do they (tapered Dobinsons) at least match the rate of OME stock height rate?

 

[LandCruiserPhil]

Since I don't drive anyone else's car and their experience does not help me in setting up my car to fit my driving style, I cannot rely on anyone's input.

I like to have a firm ride. Sports car like ride. I don't care about a plush ride, able to absorb bumps. I want it to be able to corner the way I want to, evasive maneuvers should not be a near death experience.

Soooooo, I want some stiff springs. Now, I need to know what the damn compression rate is on those Holy Springs.
Should I go with Slinky? OME? or others?

Yes, the shocks make a huge difference too, I also like them HD.

And, no I don't carry any weight. I took out the 3rd row, took out the spare tire mechanism from under the car, to make up for the added weight I got on my custom made rear bumper with a spare tire holder on it and the ARB up front.

Some people would have their kidneys fall out driving my car, but it is my car and I want it in a particular way.

Do they (tapered Dobinsons) at least match the rate of OME stock height rate?

You need to sell the 80 and buy a LX470 if you want to be happy

 

[txlonghorn]

OME stock height springs are 170/250 and 170/260 F/R dual rate respectively.

 

[Dragos80]

You need to sell the 80 and buy a LX470 if you want to be happy

I am happy with mine now, but if I ever decide on a higher lift, I still want to maintain some of the driving characteristics I am enjoying currently.