[C2] Cutting a Coil Question.
#1
Safety Car
Thread Starter
Cutting a Coil Question.
I have some brain fog going on and I need someone to straighten me out. Sort of hard to explain but:
The lower A-arm spring seat is contoured to match the contour of the spring that sits in it. Basically spiraled like a thread on a nut or bolt.
If you cut anything less than a full coil (360º worth)----wouldn't you hardly be lowering anything? Like if you cut only half a coil it would still be standing on a "ramp".
Thanks in advance guys!
The lower A-arm spring seat is contoured to match the contour of the spring that sits in it. Basically spiraled like a thread on a nut or bolt.
If you cut anything less than a full coil (360º worth)----wouldn't you hardly be lowering anything? Like if you cut only half a coil it would still be standing on a "ramp".
Thanks in advance guys!
#2
Le Mans Master
Member Since: Jul 2018
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There is a lot of science and a bit of seat of the pants engineers to coil cutting. You don’t just lower the car, you change the spring rate making it slightly stiffer. To your question, think of the spring as the hypotenuse of a right triangle with the perch being the horizontal side and the height of the spring where you cut it as the vertical side. The vertical side represents the height of the SPRING that you cut, but not the amount you will lower the vehicle. That amount is based on a number of factors including the new spring rate and vehicle weight, so any cut you make will lower the vehicle, but how much is the question.
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jerry gollnick (11-22-2018)
#3
Le Mans Master
I went through this on a GM A body. First to answer your question it depends on how the top of the coil spring is configured. If it's flat you can cut part of a coil and rotate it to index correctly. Now what I did was cut 1/2 coil and not much change. Cut another 1/2 a coil and big change in ride height. So it is not a 1:1 ratio like a lot of people think.
Last edited by Vette5311; 11-22-2018 at 04:16 PM.
#4
Race Director
What Factoid and Vette5311 said. I'll add it's better to error on not enough that cutting too much off. I would suggest not cutting more than 1/2 a coil before a test fit. You would be surprised how quick you can take the springs out and back in after the 1st time.
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3JsVette (11-23-2018),
woodsdesign (11-27-2018)
#6
Instructor
Yes, you have to cut one complete full coil's worth. I did it on mine and it worked out fine. From my point of view, if it did not work out, I would need to replace the springs anyway.
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ptjsk (11-24-2018)
#7
Safety Car
Thread Starter
I started this springtime with cutting one full coil. Hardly made a difference. Couple days ago I cut an additional 3/4 and it hardly dropped. Then I cut the last 1/4 coil-------total of 2 full coils from stock. Cutting the last 1/4 allowed the spring end to drop into the lowest point of the pocket-------you know, right were that drilled hole is. This brought her right down to where I wanted it.
Again much appreciated.
#8
How much did removing two coils lower your car? Were the springs standard or F41? and is your car a small block or big block? I am interested because I also have a 66 small block car that I would like to lower.
#9
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When I changed from iron heads, water pump, and intake to aluminum on my sb `65, the front rose a bunch. After some calculations, I had .6 of the coils (standard) removed. That dropped the front by about 1.7 inches, more than I'd expected but it sure looked good.
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C2CorvetteBob (11-26-2018)
#10
Safety Car
Thread Starter
You'll have to forgive me for poor record keeping, but I'd say it went down the better side of 3.5 inches. Stock '63 springs, still had the tag on it. Small block. You'd think at 2 coils cut it would be dragging the ground but it didn't work out that way for me. I did drive the car around to settle the suspension.
Spring uncut:
One coil cut:
Now with 2 coils cut:
Spring uncut:
One coil cut:
Now with 2 coils cut:
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C2CorvetteBob (11-26-2018)
#11
Safety Car
To answer the original question if the lower control arm and frame are original they have indentions for the spring ends. This is where the spring is going to want to set. If you want less than a full coil removed then to do it correctly you would want to cut equal amounts from each end so the spring will set the way it wants to. Cutting a half of a coil off of one end isn't going to do as much as cutting a quarter off of each end.
now to the final pics. Not only did cutting the springs enhance the stance it helped the color a lot as well.
now to the final pics. Not only did cutting the springs enhance the stance it helped the color a lot as well.
Last edited by Robert61; 11-27-2018 at 10:06 AM.
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426 Hemi (11-27-2018)