DIY spring Stiffener

[ndselvam]

Wat you are saying in technically right- but when u cut the rates increases- the comfort is totally gone -thats when u get bumpy ride-

Here we are trying to make our own effort to save money and get wat we want .

The advice to cut spring is not good - since its going to loose comfort-

Anyway all opinions are good-Thanks for ur technical info bro-



I got an idea but i dont need to try it



The idea is to get old rubber bush and slot it in between the spring -Try it out- just an idea--

 

[sam1741]

yes...
its all about hard rubber to slot in middle of spring
when some coil cannot move.. the moving coil become less.. than our spring rate increase

i heard about it before
but not saw before
anyone got pic?
what is it call? i wan to buy and DIY also
but i dono what it called

bro, please do some research and get the facts right before flaming others. cutting springs does indeed increase the spring rates (stiffens it).

Basically, Spring Rate is the amount of weight needed to compress a spring a certain . Springs are rated in LB/in (in metric system kg/mm), or specifically, how many pounds of weight are required to depress the spring by one inch. To convert LB/in to kg/mm international, you must divide divide figure by 56. Consider you have 2 springs having different spring rates: One with 345 g/mm and the other with 480 g/mm. So what does it mean? It means the 1st spring will compress 1 mm if you put a load of 345 grams, while the 2nd one will not. The 2nd one will need a 480 g. load to compress 1 mm. According to this, we can say that the 2nd spring is harder than the 1st one, or we can state that: Springs that have a low Spring Rate are soft, while springs that have a high Spring Rate are stiffer. If there are 2 different values listed, it means that the spring starts at one rate, and ends at another rate under full compression. For example: a 10lb to 25lb progressive spring will need 10lb to compress it the first inch, then 13lb the next inch, and so on, until the end of the travel; it will take 25lb to compress it the last inch. The benefit of this is that the spring can be soft enough at the start of the travel to offer a soft ride yet be stiff enough at the end of the travel to performance well during hard braking and turning. What Affects the Spring Rate? There are 3 things that affect the spring rate: 1. Diameter of the wire: Diameter of the wire itself affects the spring rate because when diameter of the wire increases it gets stronger, meaning a wire which is harder to compress. So, if we know that a wire becomes harder when its diameter increases, we can say that: When wire diameter increases, spring rate increases. 2. Diameter of the spring: That is in fact `the mean diameter of the spring`, achieved by subtracting the diameter of the wire from diameter of the spring: The overall outside diameter of the spring (mm) - diameter of the wire (mm) When diameter of the spring increases, the spring rate decreases. 3. Number of Active Coils (length/height of the spring): Determination of the number of active coils varies according to spring design. Count the total coils minus two for springs with both ends closed. Count the total coils minus one for springs with one end closed and one end open. As the number of active coils decreases, the spring rate increases. Normal Springs has a fixed spring rate. Step Linear Springs are springs which have 2 different spring rates. Progressive Springs have a variable spring rate.

info taken at Tuning Car for Find Out What is Spring Rate

bro, you are so nice to explain to him...
usually i not bother to explain also
he seems so 'certain' and also insult others when he post
and all he post is a joke for us to laugh at... if me i not bother to explain also. :)
simple secondary school physic also not understand
like our 'semi value' who never graduate primary school and talk loudly in front of TV

 

[cekau]

if all the work gone into the drench .. just buy new sets of stiffer spring .. heheh

 

[melvtec]

just like those adjustable 1, when u lower the car height, the car will ride harder. same thing from the formula.

ye ker?i'm using adjustable but when i adjust to lowered the car...the ride is not harder...but must adjust the soft/hard setting to get the better setting i want...i think the stiffness ur suspension is not from ur spring only but combination wif ur absorber...that why adjustable come wif hi/lo or soft/hard or fully adjustable wif hi/lo n soft/hard...n i dont think cutting spring will stiffen ur ride!
TQ

 

[m a v [3] r i c k]

Hi,

Hope I'm not wrong.

Cutting springs and compressing springs are 2 different things.

Cutting springs means you still have the same spring diameter, same diameter of the wire and same number of coils per unit length (but of course your springs are shorter thus having less coils). The only difference is the length of your springs is shorter. The property (or the stiffness) of the springs remain the same.

Compressing springs does increase the stiffness of the springs due to increase of number of coils per unit length. Springs are compressed using heat and we know heat changes a property and characteristic of a metal/steel. In this case, the characteristic of the springs is changed.

But thickness of the wire of the springs is not the only factor that detemine its stiffness, property and characteristic of the material used is also taken into consideration (harder material with smaller diameter could be stiffer than softer material with thicker diameter)

So IF I'm not wrong, cutting springs does not make the springs stiffer. Only makes your ride lower.

 

[sam1741]

well number of coil do affect stiffness.
Given the material is the same.
the less number of coil, the stiffer the spring.

 

[m a v [3] r i c k]

sam1741,
Given the same material, I think the more number of coils the stiffer the springs.

 

[sky_lor]

anyone noe where can i get the spring cushiong that mention by xtorm?bcoz i really need this thing because when i fetching ppl, the rear tend to be too soft and will hit the fender...

 

[am_izham]

Hi,

Hope I'm not wrong.

Cutting springs and compressing springs are 2 different things.

Cutting springs means you still have the same spring diameter, same diameter of the wire and same number of coils per unit length (but of course your springs are shorter thus having less coils). The only difference is the length of your springs is shorter. The property (or the stiffness) of the springs remain the same.

Compressing springs does increase the stiffness of the springs due to increase of number of coils per unit length. Springs are compressed using heat and we know heat changes a property and characteristic of a metal/steel. In this case, the characteristic of the springs is changed.

But thickness of the wire of the springs is not the only factor that determine its stiffness, property and characteristic of the material used is also taken into consideration (harder material with smaller diameter could be stiffer than softer material with thicker diameter)

So IF I'm not wrong, cutting springs does not make the springs stiffer. Only makes your ride lower.

u see, a coil spring is just a torsion bar (do a search on wikipedia) that is wounded up to form a coil. the nature of torsion bars is that the longer the the softer it will be and vice versa.

so the idea of a cut spring is the same as cutting the torsion bar. yes, you still have the same spring diameter, same diameter of the wire, but it will have a shorter overall length of the wire as in shorter torsion bars thus, harder spring rates.

but, cutting a spring by just a coil doesn't increase the rate that much depending on the design of the original spring. let's make some examples: a spring that has an overall height of 10 inches and has 10 full coils, if we cut one(1) coil we will increase the rate by 10% and at the same time reduce the height by 1 inch.

 

[sam1741]

izham, nice example there.
totally agree, :) to be honest i never think of that way also
i always think of spring fomulae only


cant beleive many ppl here not even study secondary school.
no offence here, but some thing just almost as easy as common sense.
there are many nice people here giving good explaination and example here.
well its none of my business if anyone got the wrong idea or right idea. your mind is own by yourself.

 

[Penghanyut]

cant beleive many ppl here not even study secondary school.
no offence here, but some thing just almost as easy as common sense.
there are many nice people here giving good explaination and example here.
well its none of my business if anyone got the wrong idea or right idea. your mind is own by yourself.

That statement of yours is really unnecessary. We are here to discuss our views and we can't be correct all the time. I'm sure you, at some point of time, did misunderstood some informations which could be a "common sense" to others right? How would you feel if another person were to tell you that you did not complete your secondary school just because of that?
So if you can't accept discussion here, by all means, stop reading and posting. Bear in mind, there are people whom did not have the chance to complete their secondary school are doing very well and they speak much better English than yourself.

Back to topic.

am_izham,
Agreed with your point of view. :regular_smile:

 

[GT_AUTO]

but, cutting a spring by just a coil doesn't increase the rate that much depending on the design of the original spring. let's make some examples: a spring that has an overall height of 10 inches and has 10 full coils, if we cut one(1) coil we will increase the rate by 10% and at the same time reduce the height by 1 inch.

izham,correct me if i'm wrong,but the example that u give is for race car.usually race car use linear type of spring.same as adjustable suspension(if i'm not mistaken).this type of spring only had 1 rate.for example 6 kg/mm.it need's 6 kg to compress 1 mm.if u need to compress another 1mm,u need another 6 kg.so that's mean u need 12 kg to compress a 6 kg/mm spring to 2mm.sport spring is different.sport spring is progressive type.the more u compress it,the stiffer it will be.for example u need 6 kg to compress the first mm.but when u need to compress another mm,u may need more force then the first.maybe 8kg-9kg n so on n so forth.this type of spring is suitable for street use to reduce body roll while maintaining ride comfort.
about cutting the spring,i've done it before in the late 90's n from what i've know,the spring will be stiffer cos u reduce the active spring.just my 50 cent.:regular_smile:

 

[sam1741]

That statement of yours is really unnecessary. We are here to discuss our views and we can't be correct all the time. I'm sure you, at some point of time, did misunderstood some informations which could be a "common sense" to others right? How would you feel if another person were to tell you that you did not complete your secondary school just because of that?
So if you can't accept discussion here, by all means, stop reading and posting. Bear in mind, there are people whom did not have the chance to complete their secondary school are doing very well and they speak much better English than yourself.

Back to topic.

am_izham,
Agreed with your point of view. :regular_smile:

bro.. sorry.. no offence there also

just that sometimes i feel a bit frustrated
i saw above many many nice people being polite,
and very nicely explain things to those who mis-understood
but few just cant accept the truth...

i agree also, we cant be correct all the time.
but sometimes so many nice people explaining the right fact it to us
why not take some time to think with our common sense
and also take some time to do some research..
even me myself make mistake all the time
but i take time to listen to other people's explaination,
and i also accept the truth.

and i also agree with u
many people never have proper education do better than me.
cause they willing to learn, willing to listen,




back to the topic,

gt_auto : "about cutting the spring,i've done it before in the late 90's n from what i've know,the spring will be stiffer cos u reduce the active spring.just my 50 cent"
-- i totally agree... active coil is the key.. :)

 

[xtorm]

xcus me for the quality, taken with hp...

slot tis in between the spring n get stiffer rate, its a good diy for rm32 (8 each) u wil feel tat the spring stop goin down at some point.

u can choose the high, mine is 1 inch which fits my king spring nicely

 

[sam1741]

wow.. nice~!!
may i ask where u buy it? what it called?

 

[simon]

i see so many ppl commenting on cutting spring...whether it stiffens the the spring or not...lets hear fr those actually using a cut spring in thier car...thats me lah...my is wira 1.5 & i have cut exactly 1 round of my standard coil spring from the top ( for front only) ....the rear i didnt cut at all.....

the ride feels a little harder than when i didnt cut....thats the truth !!!....i ride back to back with my company wira using standard springs so i can instantly tell the difference....the ride is stiff & a little bouncy only....its also feel nice in the highway as it doesnt bounce....cornering is acceptable level but of course not as good as when using sports coils...... one thing i want to make clear is its not dangerous / life threathing to cut spring (a little bit) as some people make it out to be...of course its very dangerous if you cut a lot....

 

[sam1741]

yes... many ppl here have experience before
and many knows the physic behind it... cutting springs do make them harder..

but i agree with what simon say, if you know the limit and calculation, its actually not that dangerous. in fact u change to aftermarket spring.. some are made harder also...
some are tailor to the acceptence of stiffness of our stock absorber...
so cutting spring.. u must know how much to cut also.


in fact.. T*tan, the custom suspension shop, also cut springs to fits on their absorber, occationally. i read it in FAQ section last time.. when they still have a forum here in zth

 

[am_izham]

and couple more arguments. u did mention linear and progressive spring rates. well, not all aftermarket springs have progressive rates. why? and why most of race cars are using linear rates? to answer this u need to understands how springs and shocks work and what are the purpose of both of these parts. i will assume that most of us already knows about this so i'm going simplify my arguments.

first, the springs. it's main purposes are 1. to support the weight of the car, 2. to isolate the sprung weight (chassis, engine, occupants, etc.) from the unsprung weight (wheels, tyres, brakes, etc.) to maximise comfort and/or traction.

second, the shock absorber. it's job is to suppress the spring's tendency to bounce nonstop. u see, if without shocks even long after ur car hits a bump it will continue to bounce. or simply said, if ur car doesnt have a shock
absorber ur car will be bumpy on ur ride from home to office and it will only stop when the car is not moving.

that's why it's very important to match the shocks damping ability (valving, piston size, oil viscosity & level, gas pressure on both compression and rebound) with the spring rate. that means, harder springs will need a harder shocks,as are softer springs will need a softer shocks, shorter springs will need a shorter shocks, as are longer springs will need a longer shocks. this is to make sure that the shocks can suppress/absorb the excess energy created by the springs.

now we know why race cars, most aftermarket springs, and manufacturers use linear spring rates, because its easier to make a shocks that responds only to one spring rate. and up until now i have yet to find a shock absorber that has a progressive damping.

also, that's why most people complains that after they fit a harder/lower spring (cut, compressed, aftermarket, or race) to their car they now have a very bumpy ride. this is because they match it with their stock shock absorber and now the shocks cannot absorb the force of the spring properly thus resulting in a very bumpy/bouncy ride.

for more, visit these sites:
1.Howstuffworks "How Car Suspensions Work"
2.AutoZine Technical School
3.Car Bibles : The Car Suspension Bible

 

[GT_AUTO]

agreed with ur statement am_izham.

 

[Cknacci]

anyone knows any recommendation place to cut a H&R spring (mercedes)??