• Welcome to the Contour Enthusiasts Group, the best resource for the Ford Contour and Mercury Mystique.

    You can register to join the community.

How much to cut front springs to lower 3/4-1"?

Status
Not open for further replies.
B

biminiLX

Hard-core CEG'er
Joined
Sep 27, 2007
Messages
1,730
Location
Pittsburgh area, PA
I want to tighten the front wheel gap slightly, only 3/4-1".
For those who have done it, how much to remove for the desired drop?
From the old search forums, looks like 1 coil should do it (but searching there can be tough).
My car only has 15k miles with OEM parts and I enjoy the ride quality and can do this for free on a lift. Yes, I would like to buy a spring/damper package, but for many reasons do not wish to this year.
Any help from those that have done this appreciated.
-J


***DISCLAIMER***Please do not turn this into a cutting springs debate. Mods please help with that. I understand some may suggest not to do this, but keep those opinions to yourself. I have an engineering background and have done the research years ago and called Eibach directly. No ill effects on my Cobra----It is safe and does not compromise a LINEAR rate spring to cut a small amount without heating the spring. Race teams and spring makers do this to taylor ride height.
 
i'd first locate the "dead" coil's and cut 1.5 out. if you cut dead coils it shouldnt effect your ride quality much. its common on the sho boards when upgrading to moog hd springs
 
I have a low mileage set of SVT springs that I have looked at trying to figure where to cut them. If cut, I don't see them sitting on the perches, the strut or spring mount, properly.
I only recall reading 1 person doing it in the years I've been here.
 
eepals said:
I have a low mileage set of SVT springs that I have looked at trying to figure where to cut them. If cut, I don't see them sitting on the perches, the strut or spring mount, properly.
I only recall reading 1 person doing it in the years I've been here.
Click to expand...

Its not done frequently because its a stupid idea.

Oh, but don't take that as a flame to open debate, only a justification for why you can't find any in search.
 
Last edited:
seems to me that he asked this not to be a debate about cutting springs.... so i dont know why people are poking at it. its his decesion hes not asking whether its safe or not hes asking how much to cut.
 
And we're all telling him he's an idiot for taking his life and the lives of other motorists in his own hands. This is a serious safety issue.
 
biminiLX said:
***DISCLAIMER***Please do not turn this into a cutting springs debate. Mods please help with that. I understand some may suggest not to do this, but keep those opinions to yourself. I have an engineering background and have done the research years ago and called Eibach directly. No ill effects on my Cobra----It is safe and does not compromise a LINEAR rate spring to cut a small amount without heating the spring. Race teams and spring makers do this to taylor ride height.
Click to expand...

I think your whole disclaimer is dumb. You want advice on how to do an unsafe mod on your suspension, but you don't want to hear from people who have valid concerns. And what do you expect the mods to do? You want them to delete posts if they don't conform to your standards? :shrug:

If you took your suspension as seriously as you take yourself, you would buy some springs or figure out to do this mod yourself. Good luck with your mod and make sure to take pictures. ;)
 
Do it right and buy a proper set of lowering springs... regardless of how much of an "engineering background" you have.
 
Last edited:
If you cut a spring you will change it's spring rate. It will get stiffer and your ride will be a bit harsher.

k = constant, pounds of load per inch of deflection
G = modulus of rigidity of spring material, pounds per square inch
d = wire diameter, inches
n = number of active coils, which is the number of coils subjected to flexure (always less than the total number of coils)
D = mean coil diameter, inches = Outer Diameter - Wire Diameter
Equation: k = Gd^4/8nD^3


Compressed height = free height - Load/k

If you are an engineer you should be able to calculate how much coil to remove for your desired drop and what the effect to spring rate will be.



Springs are heat treated to prevent sag and fatigue failure. They are tempered martensite. If you cut it use a cold cutting technique such as a water cooled cut off saw, use lots of water and cut at a slow rate. If you use a torch you must re-heat treat and paint the entire spring unless the heat affected zone is in a dead coil against the spring seat. 600F will temper the spring. You must keep the heat very localized to keep the active coils from heating to this temp.

I don't recommend this at all! but if you are determined otherwise then you might as well have some facts.
 
I'm not going to even get into some of these responses, not worth my time.
I'm also not going to get into the debate of spring cutting as I stated in the first post. I will say however that those of you who say it is a stupid or unsafe thing to do only spout regurgitated BS you read somewhere. I did the research, talked to a professional and called Eibach so I am confident that taking 1 coil from a spring without heating it is completely fine. You should also know professional race teams do this regularly and those springs will be subjected to conditions way more demanding than my car.
I should have suspected as much as this happens from any spring cutting question. Please respond only if you have done this and can answer the question---pretty difficult concept I guess.
-J
BTW---this car had cuts springs for over 10k and no ill effects:
01Cobra1.jpg
 
my_black99svt said:
If you cut a spring you will change it's spring rate. It will get stiffer and your ride will be a bit harsher.

k = constant, pounds of load per inch of deflection
G = modulus of rigidityof spring material, pounds per square inch
d = wire diameter, inches
n = number of active coils, which is the number of coils subjected to flexure (always less than the total number of coils)
D = mean coil diameter, inches = Outer Diameter - Wire Diameter
Equation: k = Gd^4/8nD^3


Compressed height = free height - Load/k

If you are an engineer you should be able to calculate how much coil to remove for your desired drop and what the effect to spring rate will be.



Springs are heat treated to prevent sag and fatigue failure. They are tempered martensite. If you cut it use a cold cutting technique such as a water cooled cut off saw, use lots of water and cut at a slow rate. If you use a torch you must re-heat treat and paint the entire spring unless the heat affected zone is in a dead coil against the spring seat. 600F will temper the spring. You must keep the heat very localized to keep the active coils from heating to this temp.

I don't recommend this at all! but if you are determined otherwise then you might as well have some facts.
Click to expand...

Actually some good info. instead of BS. I did already know this and even if you do not recommend this you would have to agree---if you cold cut a linear spring a small amout (~1 coil) from the spring seat and paint the cut end it would be safe, correct?
Even if you don't agree, I have done this as stated above and feel completely safe.
-J
 
Watch your suspension will start to break down IF you cut the springs. I even asked a few shops to do it at first but they refused because no matter how you cut it, the strut mount will mess up eventually then slowly the rest of your suspension will go bye bye.
 
Last edited:
kw8z3boi said:
Watch your suspension will start to break down as you cut it. I tried doing this at all shop but they won't do it because the springs is like a cone. Top is small diameter and bottom is a bigger diameter.
Click to expand...
Thanks for the info. Confused by your first sentence though.
From the pic it is hard to tell, but it looks like you could cut exactly a coil at the top and it would still fit the perch :shrug: .
I admit my experience is with Mustangs that do not have the coil over strut. I swapped the shocks/struts on my wife's Maxima and it looked similar and from what I remember seems doable.
-J
 
95pgt-t said:
i'd first locate the "dead" coil's and cut 1.5 out. if you cut dead coils it shouldnt effect your ride quality much. its common on the sho boards when upgrading to moog hd springs
Click to expand...
I forgot about that---I replaced my sagging rear '94 SHO springs with Moog HDs and remember people saying you can cut them.
Only car I ever swapped springs to raise instead of lower :laugh: .
-J
 
biminiLX said:
Actually some good info. instead of BS. I did already know this and even if you do not recommend this you would have to agree---if you cold cut a linear spring a small amout (~1 coil) from the spring seat and paint the cut end it would be safe, correct?
Even if you don't agree, I have done this as stated above and feel completely safe.
-J
Click to expand...

safe? depends on who does it and how careful they are. Of course it has been done many times. ... and many times the springs fails (sometimes they don't). A broken spring isn't a huge safety risk unless the broken end pierces the tire. (which has happened).

Your assertion that racing is a more severe environment is absolutely wrong. How much snow, rain, salt, rocks, ect. do race cars drive through? How often is a suspension in a race car inspected? How often is yours? How many miles does a race car go before changing springs. How many miles do want yours to go, how many years? How many potholes and curbs will a race car hit? How many will car hit? The amount of damage you will do to spring is much more than a racing team would place on a spring.

If you cold cut slowly with water you won't change the metallurgy of the spring.

If you take 1 coil off the spring rate will increase. The stress in the spring coil won't change. However the shock loads applied to spring seats and rest of the suspension will go up slightly. Not enough to be a huge concern though. You will be able to bottom out your suspension easier.

How are you planning on painting it. In the OEM world they are e-coated or powder coated. E-coat is only a marginal paint for springs. Powder does well. A can of Rustollium does very little.

The springs bimini showed have a variable coil diameter. If you cut those the spring wouldn't fit in the spring seat correctly.
 
Status
Not open for further replies.
Back
Top