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1970TA · 05-12-2008, 11:10 PM

If I cut one coil out of my front springs on my 70 TA how much would it lower it?

Geoff · 05-13-2008, 05:54 AM

Cutting coil springs is not a good idea. The spring will likely have a bend in it & could rub on the shocks or frame. Also hard to estimate how much lower the car would be.
Cheapest & best way is to decide on how much lower you want the car, then take the springs to a spring shop & tell them you want the car X inches lower. They will 'reset' the springs to the new height & they will be as good as new. I had a pair done a couple of years back & it cost $70 for both.

Keith Seymore · 07:25 PM

Cutting coil springs is a fine idea...

Back in 1975, through about 1990, we did a series of seven or eight Chevy pickups that were lowered by cutting the front coil springs (and relocating the rear spring hangers). We did not have any issues (other than you might engage the front bump stop more often - so you will need to go slower over rough railroad crossings).

In fact as I am typing this I just realized the red truck below (which was done in '87) is still in service today as a daily driver with no issues.

To answer your question directly: 1" off the spring equals 2" drop. The trucks above were dropped 4" in the front.

K

Keith Seymore · 05-13-2008, 06:22 AM

A couple additional thoughts:

a) Cut them with a cut off wheel (not a torch)

b) You will need a front end alignment when done

c) I mentioned the front bump stops - depending on how low you go you may need to trim the rubber bump stops slightly or - again depending on how drastic - trim the metal bump stops.

d) Make sure the springs are seated and jounce the front of the vehicle when taking measurements (both before and after).

K

SWEETJUDGE · 05-13-2008, 07:50 AM

ive been told NEVER cut them, you can heat them up & they will shorten

Keith Seymore · 05-13-2008, 10:35 AM

Quote:

Originally Posted by SWEETJUDGE

ive been told NEVER cut them, you can heat them up & they will shorten

I've been told that, too...

1967Clone · 05-13-2008, 10:51 AM

I would think heating them would be much worse than cutting them.

pinballDan · 05-13-2008, 12:12 PM

I cut 1/2 a coil on my 69 fb and it lowered it 2 inches . So I don't know were people come up with 1 coil is 2 inches . needless to say the springs went in the trash and than called moog for the right springs .

Dan

engineer · 05-13-2008, 01:24 PM

do not heat them up to lower them. Heating takes all the tension out of the metal and softens it. The metal will not recover and likely will fail under a load or that big pothole.

shannon2356 · 05-13-2008, 01:55 PM

I cut a whole coil off this 68 Tempest convertible. It lowered it about an 1 1/2. SO far. That is about what we were looking for. I think it will go down another 1/2 or so. With the front bumper and after the front end is aligned. I talked to a guy at Performance On-line. We ordered a new set of rear springs from them. Reason for that is the rear springs are shaped in a way that you can not cut them. So we ordered a set that lowered the rear 3 inches.

And he said to cut the front springs. He also said not to cut no more then a full coil off them. If we were looking for the car to go down more then a full coil will do it. He said to go with a dropped spindle.

If your spring is made in a way that the coil just stops? That is where you need to cut it. A lot of springs are made where one end is flat and the other just stops.
And there should be a groove in the lower A-arm that the end of the spring sits into. Make sure you turn the spring back into that.
Good luck!

pro-tour79 · 05-13-2008, 02:53 PM

first off NEVER heat coils cut them with a cut off wheel, the number off coils cut off is not a gauge to lower a car the only way to know for sure is to do the math and for that you must know the spring rate, coil wire dia. number of coils, installed height, and you need to know the lever ratio of the lower control arm as well as the wheel centerline all this affects the ride height THAT is why it is so hard to determine ride hight and why we get this type of questions.
The poor man's way is to cut off 1/2 the amount you want to lower the car, for most springs cutting off one coil will shorten the spring about 1"-1 1/2" so multiply that by 2 and you get 2"-3" lower but er on the short side because this is only a ROUGH guide

PITTSBURGH 64 · 05-13-2008, 07:35 PM

The Herb Adams Suspension book has a good section on spring cutting. He says to always use old springs.

1970TA · 05-13-2008, 08:18 PM

Right now I am at a crossroad, I just painted my subframe and in the process of trying to put everything back together and I thought I would do something now. I like the slight lowered look in the front and may run 17's on it when done.

6704gto · 05-13-2008, 08:22 PM

ive had no promblems when i used a cut off wheel,but i know if you use a torch u weaken the spring and wont be as strong as if u used a cut off wheel.1 coil is 2 inch

shannon2356 · 05-14-2008, 01:23 AM

Yes! Use a cut off wheel!!!!!!!!!!!!
And you just said that you still have this car apart?
If I was you I would put it back together just like it is. And after you have it all back together. And get the wheels you want to run on it too. Then you will be able to see what the car is sitting like. And you will know what need to be done.
I know you will have to take the springs all back out. BUT that is just what I just done.
Also it is not a bad idea to cut the springs a 1/4 at a time.
This car I am restoring. It was so high! We new that cutting a whole coil off of it would not hurt.
It just a little more work taking it back apart. But since everything will be new. It should come apart easy!
Good luck

Y81all · 05-14-2008, 06:54 PM

The reason Herb Adams likes to use old springs is because old springs have already settled so whatever you end up cutting off will be the height it pretty much stays at from then on (as opposed to cutting new coils which may settle some over time after being cut). Also, Herb doesn't like high spring rates, so again, using old/original coils is a way of preserving the rate he prefers.

chuckies76ta · 06-08-2008, 02:44 PM

Just wanted to bring this back to the top.

I just finished cutting one coil of the front springs. It lowered the car approx 1.5".. The car sat at 30" in the front from the floor to the bottom of fender. I hated it and decieded to cut the new springs.

With a little advise from P/Y and (Brian Baker) I deceided to cut them.. If anyone wants pics before and after let me know. I'll post some next time I have the car out.

I cut one coil from the bottom of each spring with a cut off saw..

Thanks
Charles

Will · 06-13-2008, 11:30 PM

For 2nd gen F-bodies and '75 - '79 X-bodies I've found that the rough guide of cutting half as much off the free length of the spring as you want to lower the car works very well. I've done it multiple times and it's always been very close.

So, you want to lower the car 2", cut 1" off the free length of the spring.

tempest455 · 06-17-2008, 09:42 AM

Ditto. Cut w/ a cut off wheel. You will not hurt the spring.

ceh1138 · 06-25-2008, 05:06 AM

a couple of quick questions;

1. dont springs tend to soften up and sag after several decades? if i wanted to lower my 73 catalina a few inches should i cut the original springs that are on it, or get new springs and cut them?

2. do shorter or stiffer shocks need to be installed to minimize bounce or any other negative effects that may arise from using shorter springs? or would stock shocks be OK?

the reason i ask is because my catalina sags terribly in the rear, and when i do the suspension i would love to have it sit a little lower all around.

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