Coil over spring rates

[Perry Mitchell]

I have coilover shocks on all four corners of my 67 Camaro. I think that the shocks need a different spring rate as they are very stiff. I wanted to raise the car 1 inch in the rear, but turning the adjusters up, the spring seems to get in a bind, yet, the car does not raise. Springs that are on the car now are a variable rate style with a rating of 175/350. There are two batteries and a large, heavy fuel cell in the trunk. Any suggestions?

[Tinker]

Is it the area of the spring, where it would be the 175 lb rate?(coils are closer spaced at free length)
It will probably stack all the lighter coils before raising the car, giving you essentially a 350 lb spring and probably a rough ride.
I am assuming this because 175 lb seems fairly light. I know I ran 225 lb on my 69 Firebird and will be switching to 275's when I get it back out.(someday lol)

[Perry Mitchell]

Yes, it is the lower half of the springs where the coils bind up. This leaves the upper portion of the spring with less travel to do the suspension work. I talked to QA one and explained my situation. He said the variable rate spring isn’t the right choice for my car. He said with the Corvette IRS suspension, dual batteries, heavy fuel cell, and Dynamat, a 400 pound spring would be more suitable. We will see.

[Tinker]

I didn't know you were running IRS. Cool!
My spring rates were for 4 link rear. Hope you got it sorted out.

[dhutton]

I have coilover shocks on all four corners of my 67 Camaro. I think that the shocks need a different spring rate as they are very stiff. I wanted to raise the car 1 inch in the rear, but turning the adjusters up, the spring seems to get in a bind, yet, the car does not raise. Springs that are on the car now are a variable rate style with a rating of 175/350. There are two batteries and a large, heavy fuel cell in the trunk. Any suggestions?

Are the coilover shocks fully extended? Coilover shocks need to be roughly centered in their travel at ride height.

Don

[Perry Mitchell]

Don. Yes, the shocks at ride height are in the middle of their travel.

[David Pozzi]

You could run as high as 600 - 700 lbs. 400 to 500 would be on the soft side