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View Full Version : Correct way to cut a coil spring?


projects
02-24-2008, 07:10 PM
What and where is the best way to cut the rear coils for 2-2.5" of drop from a 1" drop spring?
Im going to run a Eibach pro kit on a 66 chevelle, this has a 1" drop in the back from the start.

THANK YOU
JOHN R

chicane
02-24-2008, 07:34 PM
Well... first of all, that peticular spring is a progressive rate design. If you cut it... you will ruin the spring. Its not like cutting a linear spring, as you can do that successfully without issue... but not with a progressive rate design. Not to mention that its not a linear drop when you cut linear amounts to begin with, linear rate or not. One quarter cut could yield 1/4" drop. The next quarter coil could drop an inch and a half. So if you do this... just remember one thing: Cut the least amount possible to get the ride height you want... as you can always cut more... but you can never add it back.

Anyway. I learned from one of the cats that started doing this kinda thing some 56 plus years ago. What I have learned in cutting springs is that its all about transfering as little heat to the spring material itself as not to change more of the spring properties than necessary. Thus far, I have only found two ways to do this...

1. Ox/acetylene. Put the spring in a bucket, fill that bucket with sand and cut the spring hot and fast... allowing it to air cool. Next, grind the cut end to clean it up.

2. Cold saw. Liquid bath, slow speed, air cool. This normally has a much nicer end cut finish but it is much harder to fit a spring into a cold saw.

Also not to forget... when you change the height of the spring your greatly change the damper valving requirements. So some adjustable shocks will help.

zbugger
02-24-2008, 08:49 PM
'66 Chevelle? I could be wrong, but the rear coils on that car are pig tailed on both ends. You can't cut those springs to get a greater drop. You'll just have to use different springs to achieve what you want.

chicane
02-24-2008, 09:04 PM
Yeah they are both pig tailed... one end more than the other. But, you can flat perch the upper pocket (or use a jack screw perch) and use a cut spring.

zbugger
02-24-2008, 09:12 PM
Yeah, but you gotta remember that like most others, I'm lazy. That would be too much work for me.

surreyboy
02-24-2008, 10:11 PM
you can heat them and make em sag, but thats worse then cutting them, coil overs?

MarkM66
02-28-2008, 05:04 PM
My all original '66 rear springs were pigtail on one end only.

Cut off wheel works fine for cutting coils too.