Rear coil spring question

[SUPERSTOCKRACER]

A few years ago I switched out a set of 150# Strange hypercoils for a set of 125# hypercoil springs because I felt that the backend was way too stiff. This is on my 63 Plymouth Savoy.
It looked like the car was porpoising going down the track with the 150# hypercoils.
So now with the 125# springs, I only show about an inch of piston on top. If I turn up the spring it just compresses the spring more almost going into a bind but doesn't raise the car anymore.
Is an inch of piston enough showing or should I go back to the 150# hypercoils.
I finally got the correct ride height I like.

 

[Cranky]

How much shock extension do the new ones have vs total travel of your rear suspension? Compression should also be checked but imo, 150 springs are way too heavy. Don't know all the particulars on your car but I would even look at less than 125's.

 

[dvw]

I run 130#, no issue. An inch should be plenty. How much total shock travel? It'll use way more in rebound than in compression. If you want to raise the car, move the shock mount.
Doug

 

[SUPERSTOCKRACER]

I run 130#, no issue. An inch should be plenty. How much total shock travel? It'll use way more in rebound than in compression. If you want to raise the car, move the shock mount.
Doug

I wanted to 1st lower the back end because I went to a 29" tire and was able to get the tire tucked in nicely.
I lowered the shock mount and readjusted the spring and set the car back down only to see that the piston ride height is exactly the same as before. I wanted to see about another inch of piston but spring just compresses as before.

 

[dvw]

Piston height is directly related to spring load. Measure the free spring length unloaded with adjusters backed off. They should measure original length +/-- 1/8". 12", 14", etc. If not the springs should be replaced. If they're ok tighten the adjuster so it just touches the spring, then tighten to reduce the distance exactly 1". If the car won't work (not enough rebound travel), then it needs a higher rate spring.
Doug

 

[hangn0ut]

Will the spring bind before the shock bottoms out? 1" is cutting it close. Sounds like maybe a taller spring is needed?

 

[SUPERSTOCKRACER]

Will the spring bind before the shock bottoms out? 1" is cutting it close. Sounds like maybe a taller spring is needed?

I'm pretty sure it would bind.
I'm going to give it a try next weekend at our 2nd race and see.

DVW, do you have a picture of your rearend?

 

[dvw]

Here you go

 

[SUPERSTOCKRACER]

DVW, thanks, Do you have one from directly from the back with all 4 wheels on the ground? I want to see how much piston you have exposed. Thanks