Hey, I'm installing 2" lowering coils and from what I've read here, I'll need to cut them more before installing.
I'm building the car for sport touring, autocross, but I will still road drive the car.
Things I've done to reduce front end weight.
383 Stroker with aluminum heads
Aluminum radiator and electric fans
Remove all air conditioning components
Remove heater box
Remove brake booster
I also have aluminum door panels, aluminum center console, aluminum center gauge cluster, and aluminum Speedo and tach plate behind the steering wheel, and sport harness seats.
Removed all flip up hardware for the headlights, I now have fixed running lights in the grill.

The car now weighs just under 3200 pounds down from the stock weight of 3561. So almost 400 pounds lighter.

So my question is, those who have reduced weight in the front end and have used lowering coils how much have you cut off?
If at all possible I'd like to do one cut and install instead of trial and error with multiple cuts and installs.
TIA.

 

Just my $.02, I have lowered allot of C2s and C3s with coil cut... I wouldn't cut anything till I had everything installed and let it set a few days, not too hard to split upper ball joint again for exact cut to be certain
I find all cars and springs act a little different.

I've always used the Eaton Spring theory coil length cut gives twice front end drop... 1/2" off coil length gives 1" front end drop

 

I agree, install the springs and let them settle.
If you decide to cut them my suggestion is take a tape measure and stand the spring up measure its total length. Then if you want say 2 inches off slide the tape over till it reaches the length is 2 inches shorter mark it make your cut. You will be close.

 

So when you say cut a 1/2" off, the coil is standing upright and you measure from the floor to the top of the coil and wherever 1/2" lower lands on the coil, cut it there?

 

Correct. An old guy at a spring and alignment shop showed me that close to 50 years ago and it was always pretty darn close. Good luck.

 

You can cut any amount off of a coil. 1/2 turn, 1/4 turn, 1/8 etc.
The ruler method mentioned is the most accurate.

As you slide your ruler around, you will notice the first half-coil is nearly flat, and the taper increases after that.
That is why removing the first half-coil and then the second half-coil will give you different drops.
Just do it by the ruler.

 

https://www.eatondetroitspring.com/c...g-spring-rate/

 

here you go...

 

that is correct, I put the coil in a corner to stand it up straight, if I want the front lowered 1" I remove exactly 1/2" from the total coil length, I have lowered the front of many C2s and C3s and it's worked very well... I tried to copy the link and apparently did it wrong but Corey got it.

 

So according to Detroit springs I can't cut my spring coil anyways being that it's a square and coil. Or do people cut them anyways but obviously not the square end?

 

Which manufacturer is that?

Corvette Coils normally have open ends on both ends, well at least 1/2 open.
Definately not squared off ends with the last coil touching.
Plus those look like a dual rate coil.


Typical C3 replacement 460# Moog Springs

 

I wrote a spread sheet to help us decide about how much we would need to cut, to get "X" drop.
It seems accurate enough.
But I would still measure and cut as above.

Since you know your weights, you should be able to change that to get it to work for you.

 

My original springs look like that. And these are dual rate springs from Ridetech. 2" lowering springs. But as I originally said, most threads I've read say guys are only getting 1" out of them. Plus, I've reduced the weight a lot in the front end. Which is why my post is about cutting them.

 

Those Ridetech springs have a huge dual rate. Comfortable vs very stiff. 480/700.

They need to ride normally in the 480 section and hit the 700 section in ~1" of bump.

I would think cutting these would mess that up.
The top 3 coils are designed to all bottom out at the same time, increasing the rate.

First thing I would do is contact Ridetech and find out the design load that gives the correct 10.0" ride height.
800# 900# 1000# etc.
Then compare that to my spreadsheet.

FYI C3 springs are 10.0" long when compressed, with normal loads, and at normal ride height.
There are dozens of different weights for stock C3s, so there are dozens of different springs, to give the same ride height/bumper heigh/D height..
This one spring can not possibly work well for all of them.
Your car is now on the lighter end of that spectrum, like a 68-70.

IMHO Once you try them on, if you need to cut, I would cut the wider spaced coils, in the bottom of the pic above.
So yeah they can still be cut. And the ride height will drop as planned. But whether you still have a 480 spring rate at ride height is anyone's guess. It may be that, or 700+.

 

Or should I return them and cut my original springs? Cutting them will make them stiffer and with the KYP shocks it's already very stiff. All my body weight on any corner, bounce, virtually zero movement.
I torn on using or returning.

 

What's the code or number on your spring tag?
About six OEM springs for your year.
They are in my spreadsheet.

 

AHY? That's all I can make out

 

Easiest and cheapest would be to cut your stock springs.

Where are you located?

I have a set of VBP/Vansteel #550 drop springs I removed from my car earlier this year.

 

All good. I contacted Ridetech and I can cut their springs if needed. They said to cut the loosely wrap end. So, I'll put them in as they are and go from there.
Thanks for the help. 😎

 

Global West has a you tube video on cutting springs.