Coilover springs

[Hackerbilt]

Just wondering guys...
What is the common outside diameter for a coilover spring?
I've been told mine are an odd size and I'm gonna have a time finding new softer ones.
Mine measure 3" outside and inside will be tough due to the car still resting on them.
Looking thru a Speedway catalog showed a couple of inside measurements but nothing on outside diameter.

 

[old round fart]

measure the diameter of the wire ,double it and subtract from the OD of the spring will get you close.

 

[Hackerbilt]

True enough.
What I need to know is the width of the springs that are commonly available...not the ones I have.

 

[EX JUNK]

Mine have a 3 5/16" O.D. with a coil diameter of 3/8" which equals an I.D. of the coil to be 2 3/4" if my math is correct. And I bought mine from Speedway.

Jim

 

[fluidfloyd]

Just wondering guys...
What is the common outside diameter for a coilover spring?
I've been told mine are an odd size and I'm gonna have a time finding new softer ones.
Mine measure 3" outside and inside will be tough due to the car still resting on them.
Looking thru a Speedway catalog showed a couple of inside measurements but nothing on outside diameter.

Hackerbilt...Normally springs used in coilover shocks used in the hot rot industry will have a standard ID. I believe Jim has stated that his are 2.75" on the ID and I believe that to be correct and the industry standard. As the load is made heavier the wire diameter will increase accordingly and so will the OD. Like wise as the spring is made of smaller diameter wire the spring rate will decrease along with the coil OD. By keeping the ID the same most all coils will fit most all shocks. It does not take much wire diameter increase to make big changes in load capacity. I would not worry about the actual diameter as it is not taken into consideration when calculating spring weights. Any spring salesman can walk you through with this. Hope this will help you out. Good luck with your project.

George

 

[Hackerbilt]

D'oh...yeah that ID being the constant makes a lot of sense! LoL

I'm pretty busy at some home stuff right now and trying to keep my sanity(?) by thinking about some of my little winter projects planned for the Roadster.
Managed to grab a caliper while up getting a tool or two and my spring diameter is around .425".
3" OD - (.425 +.425) = 2.15" ID.
Seems like I just might have some oddballs...
The car was originally built in the late 70's and I have no idea what was a common shock during that time period.

Maybe I'll have to experiment with shock angle a little bit instead to see if I can soften the ride a tad.

 

[fluidfloyd]

Well, I told you wrong. After revisiting my thinking and Jim's calculations I realize we both are fogged in today. Jim's correct ID would be 2.625 ID. Looking at AFCO shock specs that is what they call for. I was going to check the Strange sight but their server is down right now. I have included a link to AFCO showing you there spec sheet. Sorry for the confusion. I will try and measure a set tomorrow for you as we have several around here. I am just on a really oof day right now.

George
AFCO Double Adjustable Coilover Shock w/ Spring Kit, 3 Stroke, 9.9 Comp.

 

[Hackerbilt]

Been doing some googling and it seems like 2.15 ID springs are not available.
2.25 on the other hand are fairly common and it's VERY possible I missed the wire diameter a smidge, thus throwing off my ID measurement.
I'm confident that they are actually 2.25 ID springs. It just makes sense.
Now I need to determine the current spring rate so I can decide how much softer I need to go.
I'm guessing I should go with an individual spring rate comparison to make a proper choice...as opposed to just seeing what the "in use" rate is mounted to the car.
On the car I'll need to consider the placement and angle of the shock and I think that will just confuse the issue for comparison purposes when looking at a specified rate spring in a catalog.
Can the specified rate for my unknown springs be checked without actually removing the spring???