| Author | Topic |
|---|
Location:
Central Coast
Registered:
March 2003
|
|
Cutting springs
|
Wed, 30 April 2003 01:02
|
 |
|
Ok here is the thing, my mate wants to lower his car but cant afford lowered springs so he is going to cut his springs for now. He wants to lower his car by about 40mm but wants to know how to do it and if its just as easy as putting a ruler beside the spring and cutting 40mm off.
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 01:07
|
|
Tell your mate to get a ruler and smack himself in the head.
|
|
|
Location:
West Sydney
Registered:
February 2003
|
|
Re: Cutting springs
|
Wed, 30 April 2003 01:09
|
|
Dont recommend it, it is not safe.
Cutting a coil to a coil and a half off will probably give him the ride height he is after, but once again i wouldnt recommend it.
You can get King Spring Super lows for about $99.00 pair then fit them yourself - better and safer.
Maybe even try having the springs reset, not sure on the cost of that though....
|
|
|
Location:
Lost in the K hole
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 01:22
|
|
do a search - this thread has been done to death
in summary, its a really f stoopid idea
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 02:06
|
|
I would cut my springs. I think it is a great idea.
I am also make stupid recommendations on car forums. 
|
|
|
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 03:19
|
|
I think the "nays" have it...
Think of it this way, if you're lowering the car, you need a stiffer spring (for compression damping) so the car doesn't hit the bump stops...Better yet, a variable or "progressive" rate spring - like the Kings, would do this. Cut springs, however, are constant rate, and are designed to work at OEM height.
In addition:
Cutting the springs will weaken the metal, particularly around the cut area.
Putting cut springs back in the car is dangerous because they will "move around" in the holders, and can actually fall out in certain conditions...
In short, don't do it!
|
|
|
Location:
Sydney
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 08:55
|
|
Heres the clincher that will definetely put him off doing it assuming he didnt already know this
Cutting springs does not make your car handle better...
Some technical BS about how springs have different tension as u go up or down the spring...so cutting them puts it out of whack
cant remember exactly but yeah cutting springs makes your car handle worse
Ta
Mani
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 11:41
|
|
Actually, you could do it with the proviso you actually knew what you were doing. However given that you are asking us how much WE reckon you should cut your springs displays that really you have minimal understanding how your suspension might work. You make no mention of installed or free height,spring rate or maximal shock travel so nobody can give you a correct answer. Furthermore I suspect you don't have a springworks at your disposal to heat and cure your springs after you have cut them. Therefore it is much safer to just tell you to not cut your springs. Apart from voiding any insurance you might have, you may potentially make your car a death trap.
Your cut spring rates will be significantly altered (altering the handling characteristics of your car), the ends of the spring where you cut it will not be correctly treated and may sag with time, the spring may not be captive such that at the extremes of travel the spring may become unseated/fall out depending on your suspension type.
In short, don't do it. Take your springs to a springworks and ask them to do it for you. They can reset your springs for $20-30
or make a pair for $80-90.
|
|
|
Location:
Montrose, VIC
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 11:46
|
|
Swankie, your mate doesn't happen to drive a 1987 Holden sedan, does he??? 
|
|
|
Location:
Coffs
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:00
|
|
| Norbie wrote on Wed, 30 April 2003 11:07 |
Tell your mate to get a ruler and smack himself in the head.
|
now that is a class call.
|
|
|
Location:
Central Coast
Registered:
March 2003
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:00
|
|
|
Nope, he doesnt drive a holden sedan
|
|
|
Location:
Brisbane
Registered:
October 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:05
|
|
yeh do it its a good idea, just like my brother in law did, he cut VK commodore springs and jammed into in his gemini{to compensate for the different spring rate}, was doing 30 k down a hill dropped into 3rd, with the rock hard suspension compression locked the car into a barrier and wrote it off
cheap shit wouldn't spend $500 for new spring AND shox and it end up costing him $5000 {no insurance}
|
|
|
I supported Toymods
Location:
melbourne
Registered:
June 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:07
|
|
bah, pussies. just cut the damn springs 
where can you get kings for 99.99 or whatever a pair???????
cutting the springs will increase the spring rate, (it will make your car handle worse on the road, because you need softish suspension on the road, otherwise it will skip over bumps and you will lose traction)
to work it out, roughly
new spring rate = original spring rate*(original length/new cut length)
probly not a good idea, unless you only cut one coil off, i would try this if it would lower my car enough, might still try it, as i have the originals lying around. (but ill check to make sure they stay seated)
edit: need a spell chequer
[Updated on: Wed, 30 April 2003 12:09]
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:46
|
|
| shinybluesteel wrote on Wed, 30 April 2003 22:07 |
edit: need a spell chequer
|
The forums have one lol ...take a look next time you reply!
Cheers
Wilbo
|
|
|
Location:
Hornsby, N.S.W
Registered:
September 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:50
|
|
| swankiedude wrote on Wed, 30 April 2003 11:02 |
Ok here is the thing, my mate wants to lower his car but cant afford lowered springs so he is going to cut his springs for now. He wants to lower his car by about 40mm but wants to know how to do it and if its just as easy as putting a ruler beside the spring and cutting 40mm off.
|
may god, if you guys knew how many times i have writen reply to this very same question. Man the answer is simple DONT DO IT!
1: DANGEROUS
2: Uneven Tyre Wear
3: Voids all warranty
4: Voids vehicle Insurance
5: Fucks your shocks
6: Fucks your bumps stops
7: Creates a very unstable bounce
|
|
|
Location:
Hornsby, N.S.W
Registered:
September 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 12:52
|
|
Never done it,
Never will
CAUSE IVE SEEN THE CONSIQUENCES!!! 
NOT PRETTY
JUSTIN 
|
|
|
Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
|
|
Re: Cutting springs
|
Wed, 30 April 2003 23:52
|
|
also, don't forget to ask your friend if he would like a big fat hole punched through his struts and strut top, because that is inevitably what could happen.
| Quote: |
cutting the springs will increase the spring rate, (it will make your car handle worse on the road, because you need softish suspension on the road, otherwise it will skip over bumps and you will lose traction)
to work it out, roughly
new spring rate = original spring rate*(original length/new cut length)
|
I fail to see how the laws of physics allow a spring reduced in length and otherwise unchanged is able to increase its spring rate. As far as i was aware, by cutting the springs you are maintaining the same spring rate as before, if not, you are reducing it. Either way it simply is NOT COOL because you end up with a car that does nothing but bounce all over the shop, have crap arsed handling, bottoms out ALL THE TIME, and is generally unsafe.
Please, listen to the negative recommendations here - they aren't wrong!
In short, don't do it. Illegal. No insurance. Dangerous. Crap.
|
|
|
Location:
Central Coast
Registered:
March 2003
|
|
Re: Cutting springs
|
Thu, 01 May 2003 00:27
|
|
|
Well I have showed him everything you guys have said about it all and he has strongly decided against doing it. He will just wait till he can get a new set of lowered springs and do it all safely and properly. Thanks for all the info guys
|
|
|
Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 00:30
|
|
your welcome 
Glad to see we persuaded your friend to choose wisely. He should really only need max $400 to get lowered springs supplied and fitted at most reputable suspension shops. Sometimes less. Ask around
|
|
|
Location:
West Sydney
Registered:
February 2003
|
|
Re: Cutting springs
|
Thu, 01 May 2003 00:33
|
|
| shinybluesteel wrote on Wed, 30 April 2003 22:07 |
where can you get kings for 99.99 or whatever a pair???????
|
Email me if you are interested and Ill get you a firm price with freight. A friend is able to get them through a supplier.....
|
|
|
I supported Toymods
Location:
melbourne
Registered:
June 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 00:56
|
|
hey, i don't recommend cutting springs at all, ESPECIALLY for people who don't have a clear understanding of what they are doing.
the formula i gave is roughly right, if you shorten a spring (and don't change anythiung else), its rate is increased, this is definate.
simple way to cheak,
get ruber band, cut it so it is one long bit of rubber, measure free length, hang weight on it, measure stretched length.
cut this long bit in half, repeat experiment, it will not stretch as far due to its spring rate being increased.
look up springs on howsuffworks.com if you don't believe me.
a car with cut springs will bottom out more because it doesn't have to travel as far to hit them, not because the spring rate is reduced.
Micbod, PM soon to be sent.
|
|
|
Location:
Cabramatta, NSW
Registered:
May 2002
|
 Re: Cutting springs
|
Thu, 01 May 2003 01:44
|
|
Err... With the rubber band, you're extending it, not compressing it. Different physics involved.
Here's an exercise, grab a stapler and rip the spring out of it. Check how firm it is. Cut it in half and check how firm it is.
You'll find that the spring rate does not change.
The formula you're giving is one for calculating the spring rate of a NEW spring which is shorter. Two totally separate springs, not one that's been cut.
|
|
|
Location:
Cabramatta, NSW
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 01:47
|
|
| shinybluesteel wrote on Thu, 01 May 2003 10:56 |
a car with cut springs will bottom out more because it doesn't have to travel as far to hit them, not because the spring rate is reduced.
|
If the spring rate was increased at the same ratio as the amount cut, then the car would not bottom out any more than it did.
The fact that the spring rate is unaltered, but you have less travel, means that you will bottom out more often.
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 01:58
|
|
| Nark wrote on Thu, 01 May 2003 11:44 |
Err... With the rubber band, you're extending it, not compressing it. Different physics involved.
|
Same physics, just different direction.
Nice basic link for all to read.
And another. The formulae at the bottom of this webpage are very handy.
Spring rate is dependent upon length.
|
|
|
Location:
Central Coast
Registered:
March 2003
|
|
Re: Cutting springs
|
Thu, 01 May 2003 02:04
|
|
What the!!! You guys are bloody confising.
Ok here is how I see it, factory springs are obviously longer than lowered springs therefore they are a much softer spring because it has alot of extra travel in it compared to that of a lowered spring. If you cut one of these springs then yeah the car will be lowered but because you have cut a soft spring, the car will keep bottoming out because the spring is not set up for such short travel.
Hmmmm, maybe that will only make sence to me!!!
|
|
|
Location:
Brisbane
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 02:04
|
|
Dammit GT you beat me to it, I was just about to post up hooks law and a brief explanation! NOT FAIR!! lol
Is there anything High school level physics can't explain?
(seems like everyone likes being a bit of a smart arse on these forums )
Cheers
Wilbo
|
|
|
Location:
Cabramatta, NSW
Registered:
May 2002
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
|
Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 02:47
|
|
|
OK, we have all prooved our points now, so lets just leave this topic be, OK?
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 05:29
|
|
Also added in this nice calculator I just found which will demonstrate that the rate does in fact increase when you chop out some coils. Have a play with this one, leave everything else alone and just change the number of coils. You will see that reducing the number of active coils (in effect, what people do when they chop out a coil) actually increases the spring rate.
Cheers Dave.
PS: this isn't a pissing contest, it's just getting the facts straight. I hope nobody is offended by this relatively innocent post, as that is not my intention.
I will now leave this topic (and others just like it) well alone. Forever.
|
|
|
Location:
Cabramatta, NSW
Registered:
May 2002
|
 Re: Cutting springs
|
Thu, 01 May 2003 05:52
|
|
I found a better one!
http://www.efunda.com/DesignStandards/springs/calc _comp_designer.cfm#calc
(you may have to delete the cookies after a few plays with it)
Just pay close attention to the maximum load.
Logic tells me that the spring rate shouldn't change on a linear spring, but I think I have the laws of physics against me...
Must be something I'm missing...
You win this time, but I'll be back!! 
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 06:08
|
|
Well OK, one more post.
That is a nicer calculator than the one I found!
Cheers Dave.
|
|
|
Toymods Social Secretary
Location:
Sydney
Registered:
July 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 06:19
|
|
Dave,
sorry i didnt mean to give you the wrong impression, i do realise that in fact you are trying to give useful information - which i myself do appreciate (and find interesting!)
I was merely trying to avoid the topic going pear shaped and getting into a slinging match, and my comment was directed at nobody in particular.
And i would really hate to see you leave, your contribution to the technical information contained in these forums is tops!
anyway, ill stop now
|
|
|
I supported Toymods
Location:
I renounced punctuation
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 06:46
|
|
No offence taken ...I was just saying that I won't bother posting in a 'cut springs' thread again as there are only so many times I'm prepared to say the same thing. I'm tired of it now.
It's very hard on the net as there aren't the other visual cues to signal what the intention of the post might be.
You guys are going to have to ban me if you want to rid yourselves of me! Hell, I'm even coming up for the dyno day!
Cheers.
|
|
|
Location:
Cabramatta, NSW
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 06:54
|
|
Now where'd I put that pesky Ban button?
BRB, gotta check under the couch!
P.S.: I chopped the springs in the couch so that I could sit lower... Little did I know that in doing so, it'd become more bouncy! 
|
|
|
Club Member
Location:
Sydney, NSW
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 10:28
|
|
| Nark wrote on Thu, 01 May 2003 16:54 |
P.S.: I chopped the springs in the couch so that I could sit lower... Little did I know that in doing so, it'd become more bouncy!
|
HAHAHA!!! LOL... Nice one Nark...
Now go and chop the matress springs on your bed...
|
|
|
Location:
Melbourne
Registered:
May 2002
|
|
Re: Cutting springs
|
Thu, 01 May 2003 17:35
|
|
|
Jeez this has got to be the most amusing thread i have read in a while (i.e i actually read the whole thing). I must say guys i found your infomation most informative its good to see ppl that actually know their stuff and i realised that my high school physics did not go to waste. Now to try and convince the rest of the little muzzas out there that cutting springs is a bad thing expecially for a high performance road car. It all aint about looks. On the last note ppl please if your going to modify your car dont be a tight arse, do it properly cause trying to save money now is gonna cost you more in the end.
|
|
|
