The Springs Thread

[D Farms]

I'm compiling a chart of spring specs on all springs that work with our trucks, I haven't seen anything like this and it's something that I'm interested in finding more information about. I'm also going to give a method of how to measure spring rate using only dimensions of the spring.

https://www.engineersedge.com/calculators/comp_spring_k_pop.htm

The rigidity value for steel is 11.25x10^6, use this value.

Soon I will make a Google forms to simply input all the data into a chart.
As of right now I have access to a few different sets of springs.

2002 front and rear
Tundra yy yb front
Lx 450 rear
8.0 and 7.5 wrap lc rear

In the chart there will be a few columns of specs for each including: color code, overall length, spring rate, top diameter, bottom diameter. Amount of lift won't be a category because the springs can change length over time and all of our rigs weigh differently.

I can't do all of this on my own so if you can, take some measurements of your springs and post them so I can put them into the chart.

This post will get changed soon to include the chart and measuring methods.

Thanks,

D Farms

 

[Oprah]

I like where you are headed with this. I see your point about the lift amounts, as long as people have some sort of base line for comparison (I.e. if theyve had or have a lift).

I will try to get some measurements of my OME 890's if you'd like. You already have my coilovers looks like

 

[MTD]

Google Old man emu spring rates And there is a cruiser webpage with a list of specs for every spring they make. Very very helpful if people know what they are looking at. You. Could highlight all the ones that fit our runners on that and then get the lift amount from members on here.

 

[MTD]

http://www.cruiseroutfitters.com/tech_OME_coils.html

 

[Jhelms]

I have two sets of 05-09 FJ springs in the garage which I am installing this weekend on my 01 and 02 4wd gunners. Will take measurements and before / after lift photos to add to the list. Not a lot of facts and data, but seems the 10-14 FJ springs do not add any lift but do offer a better ride.

 

[D Farms]

Google Old man emu spring rates And there is a cruiser webpage with a list of specs for every spring they make. Very very helpful if people know what they are looking at. You. Could highlight all the ones that fit our runners on that and then get the lift amount from members on here.

What I understand is that spring rate of a spring never changes, however the free length can change which is what causes sag. I want to get this down to a science. The idea is someone can measure their spring rate, and free spring length, then measure the front and rear axle weight and determine the exact amount of lift they will get out of any spring, they would also be able to determine how much the truck will sag when they load it up with stuff.

 

[snivilous]

It's engineering, you don't have to get it to a science since it's already been done

And sag is caused by cyclic fatigue as I understand, since a properly built spring won't "settle" as most people seem to think.

Also remember it's not quite as easy as weighing the truck, in the rear its that simple but in the front you have the lever arm plus shock angle (which is relative to the LCA angle). So make sure you figure that out, so then someone could measure their weight and multiply it by a constant to figure out the force the spring actually sees at ride height. For example my springs put out roughly 1600lbf per side in the front, obviously it's a different suspension but shows that it's considerably more than the ~2200lbs the front end weighs or whatever.

 

[MTD]

What I understand is that spring rate of a spring never changes, however the free length can change which is what causes sag. I want to get this down to a science. The idea is someone can measure their spring rate, and free spring length, then measure the front and rear axle weight and determine the exact amount of lift they will get out of any spring, they would also be able to determine how much the truck will sag when they load it up with stuff.

Spring rate is a function of bar diameter, number of wraps, and material type. Therefore it does not change with compression. Sagging on the other hand is the material yielding from fatigue which changes the material properties slightly.

Well it is already a science lol. I have my Design of machine elements notebook if you want to know all the things

 

[MTD]

It's engineering, you don't have to get it to a science since it's already been done

And sag is caused by cyclic fatigue as I understand, since a properly built spring won't "settle" as most people seem to think.

Beat me to it you ****er lol

 

[volkinator]

I like these threads! It's always fun to get a group of engineers together

 

[AZBub]

all I see is bla bla bla math. LOL. 2014 4runner SR5 springs are worth 1.4" over the stock 2000 blue/yellow springs.

Anyways KISS just add new findings to the master directory thingy. That way it's the "go to" for noobs and the budget conscious.

 

[D Farms]

By science I mean quantative, not qualitative. I want it to be easy for anyone to just look up their spring and see the spring rate, instead of just "oh the spring rides nice". I've seen a lot of threads where people review springs, but a lot of the springs we use(lc coils, tundra coils, 4th gen, 5th gen, fj cruiser) don't have a spring rate associated with them.

 

[MTD]

By science I mean quantative, not qualitative. I want it to be easy for anyone to just look up their spring and see the spring rate, instead of just "oh the spring rides nice". I've seen a lot of threads where people review springs, but a lot of the springs we use(lc coils, tundra coils, 4th gen, 5th gen, fj cruiser) don't have a spring rate associated with them.

Yep quantitative lol, that's what we mean too, but more to the point of calculating the spring rates needed for your personal rig and then using the available springs to meet their needs. Remember there are some engineers out there aka us

 

[MTD]

 

[D Farms]

I added a calculator in the op that does this. By taking some measurements I found that the spring rate of my front 2002 coils was 525lb/in which is consistent with what if seen people quote the stock springs as. Interestingly the 99 falls had a rate of 400, but they are longer as well. 7.5 wraps = 190lbs/in 8 wraps = 175lbs/in. 8.25 wraps = 167lbs/in. 8.75 wraps = 155lbs.

The wire diameters are all the same for the lc/ Lx coils.

 

[MTD]

I added a calculator in the op that does this.

If anyone is curious though that's how it is done. The one think we don't know though is the modulus of rigidity, that can vary.

 

[D Farms]

all I see is bla bla bla math. LOL. 2014 4runner SR5 springs are worth 1.4" over the stock 2000 blue/yellow springs.

Anyways KISS just add new findings to the master directory thingy. That way it's the "go to" for noobs and the budget conscious.

I care about the spring rate though, it's not just about how much lift.

 

[D Farms]

If anyone is curious though that's how it is done. The one think we don't know though is the modulus of rigidity, that can vary.

Sure but since it's all toyota spring steel I think the numbers will at least allow us to compare them. I can't imagine the steel in the toyota springs is that much different from the one springs.

 

[MTD]

Sure but since it's all toyota spring steel I think the numbers will at least allow us to compare them. I can't imagine the steel in the toyota springs is that much different from the one springs.

There are many many many different types of steel let alone spring steel. I will do little research. for this info matweb is a great resource.

 

[D Farms]

There are many many many different types of steel let alone spring steel. I will do little research. for this info matweb is a great resource.

I found this, Modulus of Rigidity