cutting springs

[jtbo]

Amount of inactive coils is probably always at least two, depends of course from many things, but when spring is in place active coils are those not touching others/spring cup, so if you have really really stiff spring you could have less inactive coils, which I doubt will happen with 300 springs as them probably won't be enough stiff even cutted to max.

Kg/cm^2 is spring rate of force, ahem pressure, which can be converted to force/distance, it took long time to find formula for that though, but I don't know if it really is force? I don't know too much, I just try to work out formulas I might stumble upon

In equation there is also suspension rate, but that is usually always 1:1 with McPherson struts.

All I know is that if you remove let's say 2 coils of spring, car won't drop as much as those two compressed coils have been before and general consensus of this matter seem to be that spring gets stiffer when you cut coils off. You should not warm springs when cutting coil off, that softens them

But what is final truth, I really can't say that, I don't cut springs, I just get ones made to my specs

Does this article help any?
http://www.afcoracing.com/tech_pages/spring.shtml

[Chris_C]

I don't cut springs, I just get ones made to my specs

I'll think about the rest before answering, but above quote makes most sense to me!

Seriously, I know 50quid is 50quid, but thats 2 tanks of fuel, or a tyre. Dai's (or any other spring shop for that matter will be similar... but Dai is good to us) are made to your spec, and it seems damn reasonable to me. Certainly less than what Pi etc would charge for a set of lowering springs for a Saxo.

[jtbo]

I'll think about the rest before answering, but above quote makes most sense to me!

Seriously, I know 50quid is 50quid, but thats 2 tanks of fuel, or a tyre. Dai's (or any other spring shop for that matter will be similar... but Dai is good to us) are made to your spec, and it seems damn reasonable to me. Certainly less than what Pi etc would charge for a set of lowering springs for a Saxo.

Take your time with math thing, you are far better in it than I and really appreciate that you look into it, maybe truth of that age old dilemma can be found

Getting to know someone with lathe is always a good thing when modding cars, for front shocks wearing out problem there is solution available, put shock to lathe, cut and make new thread, there you have shortened dampers that matches lowering and when you know someone with lathe it won't be 200 more like 20 from job like that

So customized front suspension it would be perhaps 70, if getting stiffer dampers that adds to cost, but still it is cheap compared what Nismo boys are often paying from certain branded stuff.

[rems]

right the mathmatics make no sence to me atal lol

i have been told that there is a way to work out how much to cut a spring to drop it by the amount you want to lower the car by but i dont know what it is

its along the lines of

measure the spring compressed and when not compressed and then the diameter of the spring or something like that

anybody have any ideas of this?

[germ]

is it not the progressive nature of the springs? in that the outer bits are softer and the center is more ferme? or part is harder anyway, my dad explained it to me ages ago but can't quite remember. its all a compromise between comfort/performance and to get a ride hide with weight while having the springs captive.

probally a load of rubish but i remember something along those lines.

[jtbo]

right the mathmatics make no sence to me atal lol

i have been told that there is a way to work out how much to cut a spring to drop it by the amount you want to lower the car by but i dont know what it is

its along the lines of

measure the spring compressed and when not compressed and then the diameter of the spring or something like that

anybody have any ideas of this?

Hmm, not sure if it is same, but if you know weight that is compressing spring and you know how much spring does compress when it is original length and spring rate of original spring, new spring rate with x amount of coils cut, then you should be able to work out how much to cut to get certain amount of lowering.

I guess there should be formula for that But I'm not that good for math either, I must use generous help of younger people that have math in fresh memory

2 coils is quite close to 40mm from my memory, there are some topics that should contain information about how much 2 coils did lower the car, but finding is quite bit of work and I'm bit too lazy bum at the moment (my excuse would be family issues)

Try searching threads containing lowering, then use ctrl+f to find and type coil, press F3 to jump next occurance, that way you should be able to find thread quite quickly, I believe. Sorry from my lazyness

germ, springs in 300 are linear, but there are also progressive springs which have decreasing radius of coils at one end, maybe it is that what your father was on about?

[filthyjohn]

Someone needs to get testing various springs really. The main reason I've gone for cut springs on my rebuild is that the proper springs wouldn't stay captive when jacked up. I've cut 2 coils off mine, just happened to be the most I could remove while keeping captivity. I'll report back about stance when i finally get the car down off the stands.

[Bazboy]

I have two coils cut off mine atm and it has dropped it by 2 inches, i haven't noticed any difference handling wise, the only difference between it now and before is it makes a few weird noises when hitting hard bumps. I am however wanting to get proper springs because its all ways worth doing things properly, so if you can afford springs do it.

just my two pence lol

Dan

[rems]

I have two coils cut off mine atm and it has dropped it by 2 inches, i haven't noticed any difference handling wise, the only difference between it now and before is it makes a few weird noises when hitting hard bumps. I am however wanting to get proper springs because its all ways worth doing things properly, so if you can afford springs do it.

just my two pence lol

Dan

i think im in the same situation atm i want to lower it but cant afford it hence why im finding out about cuttin the springs

[rems]

is this true (may have already been posted but i have a seriously bad memory)

as u know i have a 1988 340 and i have been told that if i want a full kit for the front i can get a 205 kit aslong as it is the same year

is that true?

[volvosneverdie]

is this true (may have already been posted but i have a seriously bad memory)

as u know i have a 1988 340 and i have been told that if i want a full kit for the front i can get a 205 kit aslong as it is the same year

is that true?

ive been told japanese ladies downstairs areas go side to side instead of up and down man, but upon actual inspection i found that it was indeed a tall tale.

i'd be surprised if yours is true too.

though i often am.

[rems]

is this true (may have already been posted but i have a seriously bad memory)

as u know i have a 1988 340 and i have been told that if i want a full kit for the front i can get a 205 kit aslong as it is the same year

is that true?

ive been told japanese ladies downstairs areas go side to side instead of up and down man, but upon actual inspection i found that it was indeed a tall tale.

i'd be surprised if yours is true too.

though i often am.

lol fair enough

anybody on here that can enlighten us both?

[dalahare]

How will the springs get stronger Jani?

Think of your spring as a straight bit of steel.

If you could straighten your springs into a rod, and you grabbed it by the ends and were able to flex it a bit, but then you straightened out your cut spring, which is the same gauge wire, it would end up shorter, and would therefore be harder to bend as you have less levarage.

Even though your springs are coiled, your car works on your springs in the same way as you did when you grabbed the ends and tried to bend it, and by cutting coils you are shortening the spring therefore removing the amount of leverage your car can put on it, your spring rate ends up being harder.

[Chris_C]

Think of your spring as a straight bit of steel.

This bit I certainly agree with mate and it's what I used to get my head round it. It's much easier to bend a long rod than it is to bend a short one. But this is only giving a torque again (as you say, it's the spring rate that's changing, which will be a torque as we are applying a force, and because we are varying length of the rod we have a displacement factor too)

As the short rod can only....... hang on, lightbulb coming on moment.

I was about to say that you need Hookes law, and that the force required to move a long spring is the same as trying to move a short spring half the amount (1xstiffness *2x length) == (2xstiffness * 1xlength) but...

The spring is of course stiffer, it must be, as although the spring is half the length, it can still cope with the same force applied. Stiffness is a torque, not a force. So yes, the spring will be stiffer, just not uprated as the force required to bottom it out is exactly the same as the original spring. Obviously this isn't taking into account removing inactive coils which don't do anything apart from give you extra length for no stiffness (and save you creating a silly high amount of stress on a single point of the spring cup )

So yes, it gets stiffer. But the suspension isn't suddenly uprated due to cutting the spring. I've got my head round it I'll go and quietly sit in the corner again now, thanks dude

[classicswede]

I have two coils cut off mine atm and it has dropped it by 2 inches, i haven't noticed any difference handling wise, the only difference between it now and before is it makes a few weird noises when hitting hard bumps.

Exactly the reason for fitting uprated lowerings spings. Beacuse the handling is a bit poo to start with. Don't forget 300 are reaching the age where springs start breaking.
Cutting springs is not right because of the heat affecting the heat treatment but I've never known this to cause a problem. The issue is you are messing with 20 + year old sprung steel that weakens with age