Outer Limits 4x4 Board

What are the differences between stock leaf springs and (say, for example) 2" lifted leaf springs.

Are the lifted ones just longer but basically otherwise the same? Would they have severely different spring rates? Just wondering if I can use my rear springs, which are about 6" longer than my front springs, at the front and get some lift that way, on my G60. Then of course I'd deal with the rear separately

Yes, I am a leaf spring n00b.

hey mate i havent dealed with any g 60s but from what i no of leafs springs.
if you`ve got a set of leaf springs that are standard and a set of two inch raised leafs for the same aplication ,say for the front of a leaf sprung vehicle, the only diffence should be the curve in them .
more raised leafs = more curve (u shape) over standard shape.

if you plan to put back leafs in front of your 4b .they are generally longer so you would have to change the mounts where they bolt to the chassis . and back leafs out of a ute are generaly more hightensile to take the work load. anyways that just my 2.0897cents hope it helps

they will have more curve but they must be longer to compensate for the extra arch, otherwise your shackles would always be inverting. so in terms of distance between mounts they should be the same. if you measured them with a flexible tape or piece of string they will be longer.

i'd say six inches longer would be way too much. you will also need to sus out measurement from eye to centre pin as well. I swear by reset stock springs with new longer main leafs. From my experience most susp kits for leaf sprung cars are too stiff. go to a wrecker and get a good set of stockies, take them and your car to a spring joint that specialises in leafs and go from there. it's better and cheaper, well in my opinion anyway!

mule75 wrote:i'd say six inches longer would be way too much. you will also need to sus out measurement from eye to centre pin as well. I swear by reset stock springs with new longer main leafs. From my experience most susp kits for leaf sprung cars are too stiff. go to a wrecker and get a good set of stockies, take them and your car to a spring joint that specialises in leafs and go from there. it's better and cheaper, well in my opinion anyway!

By reseting the spring are you not raising the effective spring rate, just like a lifted spring?? And it will probably sag (plenty of experience there, both hot and cold set). Longer springs are good, as they allow more flex and potentially better ride and travel. Why would the zook guys be fitting Hilux springs, if longer springs are no good. . Chimpboy, Compare the springs. If there centrepin offset and distances are propotional between the two, and you are willing to fab up some new mounts etc, go for it.

Layto....

forget higher springs. the flatter a spring is the more it flex's, so keep em stock and go with a longer main leaf and extended shackles

if u set it up right ittl walk like it has coils. if you get curved standard length springs you will be higher but stiffer n bouncier and also more chance of inverting your shackles

if you speak to the right spring places ittl cost only a lil more than off the shelf kits for alot more truck

lay80n wrote: By reseting the spring are you not raising the effective spring rate, just like a lifted spring?? And it will probably sag (plenty of experience there, both hot and cold set). Longer springs are good, as they allow more flex and potentially better ride and travel. Why would the zook guys be fitting Hilux springs, if longer springs are no good. . Chimpboy, Compare the springs. If there centrepin offset and distances are propotional between the two, and you are willing to fab up some new mounts etc, go for it.

Layto....

If longer springs were fitted wouldn't they need to be reset to fit into the standard perches on the chassis or would you move these mounts? if you moved the mounts so you didn't need the spring reset would it help with flex at all?
Cheers

muppet_man67 wrote:they will have more curve but they must be longer to compensate for the extra arch, otherwise your shackles would always be inverting. so in terms of distance between mounts they should be the same. if you measured them with a flexible tape or piece of string they will be longer.

How so? A 2" raised leaf spring just has more curve to it, in it's rested position it sits no different to if the stock spring which has travelled down 2", if shackle inversion is going to occur in a raised spring of the same length, it will occur with that same spring at standard height. A raised spring is just curved more, no longer.

To simply increase length of the spring and not touch shackle length and/or mounting position will be what leads to things like shackle inversion, because spring length, shackle length and mounting position are all relative to each other, you can't change one without changing another.

r0ck_m0nkey wrote:

muppet_man67 wrote:they will have more curve but they must be longer to compensate for the extra arch, otherwise your shackles would always be inverting. so in terms of distance between mounts they should be the same. if you measured them with a flexible tape or piece of string they will be longer.

How so? A 2" raised leaf spring just has more curve to it, in it's rested position it sits no different to if the stock spring which has travelled down 2", if shackle inversion is going to occur in a raised spring of the same length, it will occur with that same spring at standard height. A raised spring is just curved more, no longer.

The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

MADZUKI wrote:The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

I know what he was saying and i am saying that is wrong. If a spring is simply arched more over stock, it will not result in inverted shackles, because the 3 main things of leaf length, shackle length and mounting points remain unchanged. The result will be the supsension still having identical movement range, spring rate will be the only factor as to wether it can move through that full range still. If shackle inversion was to occur simply by putting more curve into a spring of the same lenght, the shackle will invert if the spring was still at it's standard height.

i totally agree that the 3 main point remain unchanged. but if you arch a standard spring more the straight line lenght from eye to eye becomes shorter.
when the length becomes shorter the shackle angle changes from just behind verticle to closer to vertical. when u go over a bump then drop suddenly bingo shackle inverts and leaf kinks

think about it!!!!

r0ck_m0nkey wrote:

MADZUKI wrote:The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

I know what he was saying and i am saying that is wrong.

its not wrong.

Umm, surely if springs are the same length, the shackles/mounts are the same and are in the same position, and the axle is in the same spot on the spring, then they are going to invert at exactly the same level regardless of their original curve?

r0ck_m0nkey wrote:

MADZUKI wrote:The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

I know what he was saying and i am saying that is wrong. If a spring is simply arched more over stock, it will not result in inverted shackles, because the 3 main things of leaf length, shackle length and mounting points remain unchanged. The result will be the supsension still having identical movement range, spring rate will be the only factor as to wether it can move through that full range still. If shackle inversion was to occur simply by putting more curve into a spring of the same lenght, the shackle will invert if the spring was still at it's standard height.

take a legnth of string, and measure it. now put a curve in the length of that string, now measure the distance between the ends of your piece of string. I assure you that the distance between the ends of your string will be less then the actual length of your string. This is primary school geometry. What your saying is mathematically impossible. Spring manufacturers compensate for extra curve by making the springs (main leafs) longer.

chimpboy wrote:Umm, surely if springs are the same length, the shackles/mounts are the same and are in the same position, and the axle is in the same spot on the spring, then they are going to invert at exactly the same level regardless of their original curve?

yes. a longer spring will give you a more horizontal shackle angle, and will therefore have to droop further in order to invert.

badger wrote:forget higher springs. the flatter a spring is the more it flex's, so keep em stock and go with a longer main leaf and extended shackles

if u set it up right ittl walk like it has coils. if you get curved standard length springs you will be higher but stiffer n bouncier and also more chance of inverting your shackles

if you speak to the right spring places ittl cost only a lil more than off the shelf kits for alot more truck

Anybody had any prices to get a custom main leaf made? I am considering this for mine. as i am using a 2" BL and minimal spring lift using flatish springs.

Nic

I had standard springs in the front of my sierra, and the springs were flat and had slightly lager shackel angle than other sierras ive seen, then i swapped them for another set of fronts that apreaed to have more arch and were aparently lifted springs. so i put them in minus a few leafs and now they are flat and the shackel is permanatly inverted so lifted springs must have longer mains. thats my theory anyway.

hokey wrote:

lay80n wrote: By reseting the spring are you not raising the effective spring rate, just like a lifted spring?? And it will probably sag (plenty of experience there, both hot and cold set). Longer springs are good, as they allow more flex and potentially better ride and travel. Why would the zook guys be fitting Hilux springs, if longer springs are no good. . Chimpboy, Compare the springs. If there centrepin offset and distances are propotional between the two, and you are willing to fab up some new mounts etc, go for it.

Layto....

If longer springs were fitted wouldn't they need to be reset to fit into the standard perches on the chassis or would you move these mounts? if you moved the mounts so you didn't need the spring reset would it help with flex at all?
Cheers

If you read my post, i said that if Chimp Boy is prepared to fab up new mounts go for it. If you fit longer springs, sure you will most likley need to move the mounts, but this is not a huge issue, and the potential for better off and onroad work can offset the extra effort involved with fabbing and moving mounts. By curving a spring it shortens the effective length of it. Think about it. Because the length of the main leaf does not change, as it is curved the distance between the eyes shortens. Take a bit of string and measure the distance between it straight. Then curve it like a spring and measure the distance between the end. Garantee taht when its curved the distance between the ends reduces.



Layto....

AnthonyP wrote:

r0ck_m0nkey wrote:

MADZUKI wrote:The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

I know what he was saying and i am saying that is wrong.

its not wrong.

Well actually it's not. For interest sake i even just measured a new stock IFS Hilux rear spring and it's leaf meaurement is identical to that of a 2" raised spring, only difference is it's curve. Other raised springs i have used for other vehicles have been exactly the same way, with more then one brand. So to just say the leaf is longer in raised aftermarket springs is wrong.

But back to the inversion. If a spring is 2" raised and is of identical length to that of a standard spring, in it's nuetral position it is in exactly the same position as if the standard spring had trvelled 2" downward. It's potential movement range will still be identical, a little more upwards a bit less downwards. So if by simply adding more curve to a spring of the same length will bring about shackle inversion, the suspension in it's standard form would have the exact same inversion problem which will occur at the exact same point.

r0ck_m0nkey wrote:

AnthonyP wrote:

r0ck_m0nkey wrote:

MADZUKI wrote:The acual leaf is longer eye to eye if you flattened it out, but the curve is greater so it keeps the same distance bewteen the eye's of the leaf.

I know what he was saying and i am saying that is wrong.

its not wrong.

Well actually it's not. For interest sake i even just measured a new stock IFS Hilux rear spring and it's leaf meaurement is identical to that of a 2" raised spring, only difference is it's curve. So to just say the leaf is longer in raised aftermarket springs is wrong.

But back to the inversion. If a spring is raised and is of identical length to that of a standard spring, in it's nuetral position it is in exactly the same position as if the standard spring had trvelled 2" downward. So if by simply adding more curve to a spring of the same length will bring about shackle inversion, the suspension in it's standard form would have the exact same inversion problem which will occur at the exact same point.

Correct, inversion will ocour when the shackle is in teh same position no matter what length leaf is on the car (theoretically anyway, there are heaps of dynamics etc im ignoring here as they are complex), BUT with a shorter effective length eye to eye due to the greater arch without lengthening the spring, the point of inversion is "closer", as the shackle is more upright in position compares to where the suspension is in its cycle. I know this from 1st hand experience, due to running standard, lifted and now spoa on my zook (dead flat springs). With the 2 inch lifted spoa springs, which were no longer in true length than my standard springs, the shackle sat more verticle, and was easyer to go inverted during susp travel. Now with my spoa flat springs, the shackle points away from teh spring ( e.g. o__________\ )
O
And takes heaps of down travel to make it point along to spring. With a lifted spring the extra arch means that less down travel is required to reach this point, making inversion easier ( or at least potentially more likley to happen).


Layto....