school me on cutting springs...

[wicked93gs]

I hear people saying they cut off half a coil here...3/4 of a coil there...I was just wondering what that translates into in terms of real world drop

 

[SoCalCruising]

A bit less than what is cut off. The spring will get stiffer when you shorten it, so it won't drop the full amount that you cut. I don't know of a formula or good rule of thumb. Sorry.

You didn't ask, but the cutting needs to be done without overheating the coil and thereby destroying the spring's temper - hardness, not making it mad . This can be done by cutting the spring while the spring is submerged in cool water, for example, with a sawsall or cutt-off wheel (taking your time).

 

[ratio411]

I don't know what drop you'll get with x amount of coil cut, but I will tell you that you need to cut the spring with an abrasive wheel. Bigger the better.

A hacksaw or sawzall won't get it, and a torch will ruin the spring tension.

I used a 14" chop saw with a steel cutting wheel when I did a spring chop on a non-Ford car.

Also, I noticed that when I cut the spring and reinstalled, the car was not as low as it ended up a day or so later. Let them settle before you decide to cut more.

Edit:
So-cal beat me to it...

 

[zookeeper]

I hate to even bring this up, but I will. Contrary to popular myth, using a torch is a perfectly good method of cutting springs. I kow that as soon as I hit the "post reply" button, there will be all manner of people saying otherwise, but it's true. I say so and Herb Adams says so in his book. How can a torch ruin a spring? I suppose if you heated the entire spring until it was cherry red and kept it covered to cool slowly you might anneal (soften) the spring, but under normal conditions, a torch does not and cannot affect the spring past the heat zone. Think I'm nuts? Try this on a scrap spring: cut a portion of the spring off using a torch, now grab the spring about 6 inches from your cut. Not even hot, is it? I'm not just spreading my opinion here, it's fact. Ask anyone who's ever taken a metallurgy class and they'll likely tell you the same thing.

 

[2bav8]

I've found a dremel to do the job quickly and easily...

 

[bnickel]

I don't know what drop you'll get with x amount of coil cut, but I will tell you that you need to cut the spring with an abrasive wheel. Bigger the better.

A hacksaw or sawzall won't get it, and a torch will ruin the spring tension.

I used a 14" chop saw with a steel cutting wheel when I did a spring chop on a non-Ford car.

Also, I noticed that when I cut the spring and reinstalled, the car was not as low as it ended up a day or so later. Let them settle before you decide to cut more.

Edit:
So-cal beat me to it...

an abrasive wheel is quicker but a sawzall will work just fine.

i've used all of the methods, abrasive wheel, sawzall and torch and i don't care who says what in any book a torch is a bad way to cut a spring. we used a torch on a friends old 66 chevy pickup and ended up with different amounts of drop between them even though we cut the springs in the same place and the truck was perfectly level before we cut the springs. we cut the springs with them out of the truck and reinstalled them exactly the way they came out.


heating any kind of spring will change the springs tension to varying degrees.

 

[CraigMBA]

I think it depends on how tempered the spring was, or how hardened the wire winds up.

I tried a sawzall and a cut off wheel and a cold saw to cut a 1/2 coil off my Pro Motorsports sold Ebach built springs and it was no dice. The hot wrench it was. Both springs wound up exactly the same unloaded height and sat even in the car when I put them back in. It really didn't hardly hurt the powder coat.

The stockers I could of cut with a butter knife.

My suggestion? Try to do it another way before you switch to the torch. It certainly leaves a nicer finish.

 

[wicked93gs]

well, I have an angle grinder and a cutting wheel, and I can always spray water while cutting, so its no big deal, I was mainly trying to figure out how much spring I'll need to cut to get my desired height when I'm done with the rest of my suspension

 

[66ccode]

This may be obvious, but as a few people have mentioned using water to keep the spring cool while cutting, I will add, NEVER USE WATER AROUND POWER TOOLS. There aint no mustangs in hell, (unless you're a chevy guy).

 

[wicked93gs]

lol, I work with angle grinders and water every day...I know how to take the correct precautions...and yes, there is a risk of shock...it doesnt hurt as much as 12v though strangely enough, but if I dont have to use water...I wont, I'll keep it to a wet rag

 

[mustangdave]

120 v amd water.........great post

 

[Helmantel]

You can get an approximation by measuring the coil spacing at ride height (suspension loaded). Say, if they’re 1”apart (center to center), then cutting ½ coil will shorten installed height of the coil by ½ x 1” = ½”. However, due to the leverage of the suspension, the wheel will go up (or the car will drop , depending on how you look at it) by approximately 1 2/3 times that amount, so the car will drop 0.83”.

This is of course just an approximation. Cutting the spring will make it a little stiffer (so less drop), the spring will settle a little and there are probably a few more variables, but it can give you a ball park idea. The above method works of course only with everything installed (not sure how far you are with your SHO swap).

 

[wicked93gs]

currently making mounts so I cant load it yet...and the fact that the engine is 150lbs lighter than a 289 doesnt help either...I may have to swap to v6 springs to start with

 

[66Restomod]

So it is safe to cut coils...as long as they are kept cool?

The GT-350 Suspension modification didn't drop my car as much as I had hoped...so I think a small cut might work...

 

[SoCalCruising]

I think the take-away message is that keeping the spring cool while cutting it reduces variation in the result.

 

[brianj5600]

I like when people think they know better than Herb Adams, he has quite a resume'

 

[iskwezm]

This may be obvious, but as a few people have mentioned using water to keep the spring cool while cutting, I will add, NEVER USE WATER AROUND POWER TOOLS. There aint no mustangs in hell, (unless you're a chevy guy).

Who uses electric tools????? Air tools!!!!

j/k

I cut 1 coil, and althoug it loos sweet and rides great, 1/2 might heva been better so the spring doesnt fall when you jack it up or put a turbo and it sits too low

 

[CraigMBA]

Who uses electric tools????? Air tools!!!!

j/k

I cut 1 coil, and althoug it loos sweet and rides great, 1/2 might heva been better so the spring doesnt fall when you jack it up or put a turbo and it sits too low

Put a 3/4" spacer between the shock and the shock mount and limit the downtravel.

 

[69 redruM]

i am lazy....

i have cut springs on an old chevy truck without removing them from the truck (just jacking one side up), anybody cut springs on a mustang without removing them ?
i need to drop the front of my 69 about 2"

 

[BlwnGazkit]

As for the metalurgy: Steel depending upon it's exact alloy begins to change it's structure at a surprisingly low 300 degrees. Now thats not really enough to cause much worry for losing the temper ona spring but at about 500 degrees it will begin to soften a hardened temper.

You're saying that 6 inches away from the cut the metal isn't that warm and you're probably correct due to the thcikness of the coils. BUT that's 6 inches of coil that are now softer than they should be and no longer provide the spring forces required nor are they predictable in how much they lose unless the temps are monitored.