Cutting springs

I have heard that cutting springs is a bad idea but I was wondering what the reason behind that was? If you have a car that springs aren't really available for why not cut them (not talking about the Yugo)?

In reply to 93EXCivic: Cutting springs is not ideal, a few reasons are that it raises the spring rate, the heat from cutting (if you aren't careful) can mess with the spring rate/make the spring weak, sometimes to cut it short enough for the desired effect you will risk it dislodging from the spring perch on full droop.

That being said I've cut springs on a Yugo. 1.5 coils if memory serves correct. A couple of zip ties to keep the spring located on the perch under full droop and never had a problem. Cut them with a cutoff wheel and did 1.2 coil at a time until I got where I wanted.

I was thinking about doing it to lower the W123 about an 1" if I can't find something like a QA1 spring which fits.

It depends a lot on the vehicle and what you are trying to accomplish. The front springs on my Mustang were intended to be cut to the proper length and rate. But they're race springs. You don't want to cut closed end springs, and you don't want to cut them with a torch. Open end springs can be cut with a saw, but the shorter you make them the higher the effective spring rate is.

I've done it a bunch of times, no issues. Don't use a torch. I use a cut off wheel and keep it cool, heat is bad.

I'm not familiar with your car, but if you have struts, you could remove the spacer from between the strut and shock tower and put it on top of the shock tower; ala BMW 2002.

Dan

You should be fine to cut the springs for that. A lot of the problems with cutting springs are actually problems with people who cut springs. I'm pretty sure that as an engineer, you're not going to take a torch to a spring though.

Wait, people cut springs with torches?!?!

Yessir. I've even heard tell of people taking a torch to spring while they're still on the car.

MG Bryan wrote: Yessir. I've even heard tell of people taking a torch to spring while they're still on the car.

Yep they heat 'em up so they droop.

There was an old practice of running a torch up and down the coil spring, while still in the car, and letting the car as on that to lower it. The results were...interesting.

From that, I guess, people concluded that getting a torch near springs resulted in the destruction of the spring. So people clamor about how you should never cut a spring with a torch.

In actuality, if you cut a spring with a torch, and aim the torch head across the coils, you'll not heat much metal and won't affect temper out beyond 2-3 inches of the cut. It's just no big deal. BTDT, quite a number of times.

That said, I usually use a wiz wheel. It's just easier and quicker than firing up the torch.

Lots of folk also squawk about grinding the ends flat, or doing weird things like that. Usually doesn't work. Just cut neatly so it doesn't have sharp edges, and then when installed, it all sits down just fine in the perches.

Since you've not done this before, may I suggest a spring compressor (if you have struts) and remove 1/4 turn at a time.

You can always take more off, putting it back on is a real PITA.

Dan

the only caveat to all of this is variable rate springs that are also variable diameter, where if you cut them, the new, larger diameter "end" doesn't fit in the perch anymore.

Other than that, I've cut down stock springs to get ride height out of a car, and I've even cut down tokiko sport springs that actually raised the car up an inch (and I wnted the car level for autocross AND looks).

Herb Adams showed how to do it properly in his books, and I figure if it was goo enough for Herb back in teh day, it's good enough for me. Just don't heat them till they sag. I've seen springs fracture and come apart that have been heated that way to lower a car.

Everything people have said here is truth. Our Lemons car had like 6 hard races on the cut springs, we cut with a cutoff wheel and rebent the last coil with a torch and careful application of heat. They never broke or dropped and performed great. Are they ideal? No, but they were free.

I have cut any number of springs with a torch and never had a problem The heat that would alter the spring does not travel that far. Just do it quickly. I suppose you could wrap a wet rag around the coil. That being said, a cut off saw is better. Less heat and more accurate.

I know a guy who sliced the stock springs on an EP70 with a torch and then put KYBs on it, the handling was way better than such a ghetto mod had any right to be.

I cut 1/2 a coil off the front coils on my 97 Jetta... After I reassembled the car with new strut mounts it didn't look like it made a difference... One day I will take it apart and whack another 1/2 coil off...

BTW, for the record I used a wiz wheel...

Half a coil is nothing. On many stock springs the first half-coil is practically solid anyways, as it's bent to nearly touch the next coil to create a flat end for the spring.

Ive cut springs many times with a cutoff wheel. But i dont cut it too short to get a slammed look and the car bottoming out when i run over a pebble. Just enough that the spring stays in place with the suspension at full droop. I also trim the bump stops if needed.

GameboyRMH wrote: Half a coil is nothing. On many stock springs the first half-coil is practically solid anyways, as it's bent to nearly touch the next coil to create a flat end for the spring.

Those are closed coils that generally aren't a good idea to cut, as the spring often will not seat properly afterwards.

I've seen some people heat the springs and bend them to get that closed coil shape back...probably not a great idea...

If you cut closed coils you'll probably go through spring seat rubber faster than usual, but it seems to work fine on most vehicles. If you do that, just make sure they won't come unseated in full droop.

GameboyRMH wrote: I know a guy who sliced the stock springs on an EP70 with a torch and then put KYBs on it, the handling was way better than such a ghetto mod had any right to be.

I'd say 80% of lemons car setups are like this. I need to do this to my DD to drop it a couple inches.

Coil springs are heat treated. The vast majority of the time, when they are torched they lose their hardness. This happens whenever the springs are not normalized afterwards. This allows them to fatigue over time and fail. Bad idea for a long term street car.

Using a torch to cut the springs doesn't matter. The place where you're cutting is a dead coil anyway.

In reply to Zomby Woof:

It's only dead if it's a closed coil, which you shouldn't be cutting anyway. An open spring design has no dead coils, and in either case when you cut with a torch there is a heat effected zone that does in fact extend into the working part of the coil. The bottom line is that in the vast majority of cases, cutting with a torch is going to weaken the coil, and there are other much safer and better ways of doing it that don't.

GameboyRMH wrote: If you do that, just make sure they won't come unseated in full droop.

I just make sure I don't go over any jumps after Iv'e lowered a car.

4" cut out of the stock front springs:

Same here:

And an inch and a half cut out of the rear Tokikos to make it sit level: