Anyone do a coil over on the rear? What spring rate and length? Going on a 3870 series afco shock

Thanks
Aaron

 

I run 110 pound springs in my car. I've run 130 pound with no problem but wanted a softer spring so the shocks could do their job. I have some 150 pound springs but know they would be too stiff.

Springs hold the weight of the car up. You only need enough spring rate so that they'll compress to a proper distance for the shocks to work. The shocks do all the work as the weight on the spring allows the shock to extend and compress. The valving in the shock controls how much and how fast that movement is.

Too stiff a spring and the function of the shock is greatly decreased since the weight on the spring doesn't compress the shock enough. Too soft a spring and the shock gets compressed too far.

With a coil over system, you can always adjust preload to raise or lower the compressed shock length. The shock mount can then be adjusted to set the car's ride height. There's a ballpark number to shoot for. If a shock has 5" of travel, the weight on the spring should compress the shock about 2". Without knowing the unsprung weight that sits on the shocks, you'll never know the proper spring rate to use. You can't just weigh the car on the tires because you're also weighing the tires, diff etc. Rear car weight minus about 500 pounds should put you close to the unsprung weight.

 

Thanks stephen

 

I run afco big guns and run 14x150. I tried 125 and it was too light

 

any pics of your rear suspension set-up? did you use the bolt in style or standard style?

 

Bolt in since they give the stud option

 

Did you use the panhard clevis on the bottom to mount it? if so did you use bushings to keep it centered?

Also wouldnt mind input on front spring for coil overs. Tried 175 first seemed like too much and didnt compress much now with 125 they are compressed a fair bit but doesnt seem to transfer very well. stock block sbc with a plate and all the usual stuff removed.

 

where is your upper shock mounts? still below the floorboard?

 

No spacers are needed when using a Clevis. I had 175lbs up front with an aluminum headed sbc.


My coilovers are mounted in the stock shock location both on the rearend and upper shockount.

 

running 12x170 in the front and 10x150 in the rear on my car

 

Xpndl3 is urs coilover or on the axle

 

rears are the wolfe racecraft kit, fronts are racecraft coilovers.