After more than a month with the 5665's, the butt of my IROC is still sitting high (higher than I want to live with). The springs are seated correctly in the isolators. I've seen little or no settling. Apparently, replacing the isolator with radiator hose will drop the ride height a 1/2 inch or so. However, I'd still require another 1/2 to get the butt to factory ride height. Will cutting a 1/4 coil get me there? Comments or suggestions are appreciated.

JamesC

 

To update. I replaced the stock isolator with radiator hose, which dropped the ride height 3/8 of inch to 28 1/4.

JamesC

 

Really that's all with that change?

 

That's all.

JamesC

 

You still want to get another 5/8" left then?
I guess you can measure your springs, and see how much to cut to get 5/8" more drop. A quarter coil from the top is a good start. Since it's the rears, it's SO EASY to remove and redo it if you want more.

oh right, the 5665's are not the progressive rate, they're the straight rate eh? Ok, cool, chopping progressive rate springs is something I like to think twice about, since you're messing with the spring characteristics more...

 

Don't forget that cutting the coils will stiffen the spring. Think of a coil spring like a long torsion bar. When it's compressed, you're twisting the bar. Cutting a coil shortens the bar, stiffening it.

http://www.efunda.com/DesignStandard...ing_design.cfm if you're interested.

If you cut half a coil off, going to 3.5 from 4 active coils (just guessing the number, haven't looked), that's 14% stiffer.

Deflection = (8*Force*CoilDia^3*number of active coils)/(material shear modulus * wire dia ^4)