Cut 1/4 off 5660 coil springs... And ruined them.

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pontiacgp

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Mar 31, 2006
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I'm fine with it now that I know there not compromised. By the way you seem to have knowledge on these 5660's. How come no one knows for sure how much of a drop cutting these will give? I heard cutting a whole coil off this spring is anywhere from 1 inch to like 4 inches

if you search the internet you'll find the info which I have posted multiple times that 1/4 coil removed will lower a G body 1".....
 

Bonnewagon

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How come no one knows for sure how much of a drop cutting these will give?
Because there is no magic formula that says "cut this much to get that". Every spring is different as is every car. On my Bonnewagon I had to cut off a 1/4 coil three times on each spring. As for the scratch I would smooth it out so there is no stress riser. Then protect with paint. Positioning it at the top would make me more comfortable but at the bottom you would know if it broke or bent easier. Your choice. As for the cutting process a cut-off wheel is best so that it doesn't heat it up and ruin the temper. NEVER heat with a torch.
 
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pontiacgp

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Mar 31, 2006
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Because there is no magic formula that says "cut this much to get that". Every spring is different as is every car. On my Bonnewagon I had to cut off a 1/4 coil three times on each spring. As for the scratch I would smooth it out so there is no stress riser. Then protect with paint. Positioning it at the top would make me more comfortable but at the bottom you would know if it broke or bent easier. Your choice. As for the cutting process a cut-off wheel is best so that it doesn't heat it up and ruin the temper. NEVER heat with a torch.

on the 5660 spring you can only cut the bottom coils and the white paint in the op's pictire of the spring shows the white paint which is the lower side of the sping.
 

Bonnewagon

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Well if you blow up that picture the cut looks a lot deeper than at first glance. Why only cut the bottoms? I can't see any difference. They are both flattened.
tantan__ra_p.jpg
 
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pontiacgp

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Well if you blow up that picture the cut looks a lot deeper than at first glance. Why only cut the bottoms? I can't see any difference. They are both flattened.
tantan__ra_p.jpg

top amd bottom isn't a big difference but the top is flattened, the bottom control arm has the channel for the open spring
 
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JAMCAR223

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The factory springs are visibly flat on the top. The Moog springs are not as flat on top, and therefor the white paint is a designation for "Top". As stated above, there is a channel in the lower control arm to properly locate the bottom of the spring, and that's why you cut the bottom side.
 
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Ribbedroof

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They're listed in my TRW paper catalog as FWO (full wire open) on bottom, and TWC (taper wound coil) on top, so they only fit correctly one way.
 
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Bonnewagon

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the white paint in the op's pictire of the spring shows the white paint which is the lower side of the sping.
therefor the white paint is a designation for "Top"
Ok I understand. But now- which end did he cut? The white paint is on the end he cut- so....?
 

JAMCAR223

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He has (2) reasons to replace them.
 
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Supercharged111

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I'm fine with it now that I know there not compromised. By the way you seem to have knowledge on these 5660's. How come no one knows for sure how much of a drop cutting these will give? I heard cutting a whole coil off this spring is anywhere from 1 inch to like 4 inches

It's a bit of a loaded question. You could math out an answer, but it could end up being wrong. How much the car drops depends on 2 things: change in wheel spring rate and change in spring height. Mac strut cars have near 1:1 wheel rates and thus can run lower spring rates to achieve the same wheel rate because the spring presses down so much closer to the center of the wheel. Don't quote me, I'm pretty buzzed right now, but I believe it's the relationship of the center of the spring pressing down relative to the distance from the LCA inner bushing to the center of the rim if that makes sense. G bodies have springs mounted farther inboard than a mac strut car, so will require a much higher spring rate to acheive a desired wheel rate just like a Fox or SN95 Mustang. Lets say you have a spring with 10 coils rated at 1000# and you cut a coil off. You have now increased spring rate by about 10% having removed 10% of the spring (I think reciprocals come into play here, but we're really splitting hairs at this point). So you've now made the spring shorter, but also made it stiffer. I'm sure there's some super nerd out there who could do a better job figuring out how much of a drop you'd see, but it's not me. I have more questions than answers, so I'd just cut a little bit a time until I got where I wanted to be regardless of the asspain of removing/installing repeatedly because I seem to be a glutton for punishment.
 
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