Coil Spring Surgery

[73vertproject]

So I'm still cooling my heels waiting for a coil spring compressor, and I'm daydreaming about a post I think I read somewhere that said a person could cut one coil out of a stock new coil spring and it would produce an improvement in the front suspension (a little stiffer handling, or better stability, or maybe just lowering the front end). Something.

Is this something I should consider (I've got a great metal shop teacher who would love to cut one coil out with a band saw - no heat, he said) for any reason? Or should I stick with the OMS that came with the new kit and not even thing about such a thing? Thoughts?

Doc

 

[72HCODE]

all cutting a spring will do is lower the front end. to make a spring stiffer you would need to change it out for a thicker coiled one.

now if you are going to change your front springs out from the oem stock to the 620lb lowered springs, then you could cut your spring with a torch heating it up till it collapses, then get the old one out, rebuild the suspension and leave the upper arm loose.

it is possible to jam the 620lb spring into the top coil holder(top part of the shock tower) and into the spring perch on the upper arm when everything is loose without a spring compressor because the 620lb spring is a very short spring by itself. once you have the spring pushed into place with the rubber isolators then start turning the 2 nuts on the upper arm and torque to the correct Ft-pounds.

since the 620 spring is like 1/3rd the length of the oem stock one it is possible to do it like this. i did it once for transport i needed to put my cars front end together ASAP to trailer it and i needed a rolling chassis but had no spring compressor at the time, so i stuck the spring into the top first pushed the Aarm into the shock tower mount and kicked the spring onto the perch then just torqued down the upper arms and mounted the lower arms loose just to roll it onto the trailer for transport.

 

[cobra3073]

I agree with the above in that removing a coil from the OEM spring will only lower the car. This in of itself, while possibly improving the handling and ride, will not provide any appreciable firmness to the ride quality.

The better option, if you are looking for improved firmness, handling and ride quality, would be to go with 620 LB springs on the front. Many of the Mustang part houses (possibly OMS, also) has them for less than a $100.00 a pair.

Contrary to what we use to shoot for in the 60s and 70s where straight line performance was the main goal, many people now want their cars to handle well also. Hence, the move toward lowering the car which usually makes for better handling.

The stock free standing height of our '71 - '73 Mustangs is said to be approximately 15" - 16" while the 620 springs drops that to around 13 inches. Cutting a coil from your OEM spring will still leave you with an "old" spring.

Of course that is an option but I chose the replacement approach(along with KYB shocks) with my '73 Grande and I have been extremely pleased with the results.

Hope this helps.

BT

 

[droptop73]

I'm not sure the springs will cut with a band saw. I cut mine with my 4" hand held grinder with a thin cutoff wheel. The top of the spring is flattened to fit into the top pocket, the bottom of the spring is the only end that can be cut. If you cut the spring off, a short section of the "tail" of the spring (approx 3") will need to be heated up and straightened to fit into the spring perch properly. A torch and bench vise will work sufficiently to straighten the tail.

 

[f117rt]

I bought a set of 1" lowering spings from CJ Pony for less than $75.

I am very happy with the handling and ride.

See photo for comparison to the stock spring.

 

[73vertproject]

OK, thanks for the info and feedback guys. I'll take everything into consideration. My main point was "since I have a brand new pair of OEM springs sitting here, can I modify them and use them to produce any type of improvement, rather than toss them and buy another pair".

It's looking like I'll probably just install the new OEM springs, because I'm not quite ready to start cutting and bending things (although I think that's right around the corner.

I'll post some pics tomorrow showing the wacky spring compressor I came up with, along with other progress pics.

Thanks again for the ideas.

Doc

 

[c9zx]

Go to this site and read the write up. Informative and authoritative. http://www.eatonsprings.com/cuttingcoilsprings.html

Chuck

 

[droptop73]

Nice article. It ought to end a couple of urban legends.

Another way to change the EFFECTIVE spring rate is to move it closer to the spindle on the control arm. A second pair of holes can be drilled 1 inch closer to the ball joint and move the spring perch.