coil over shock question

[famous bob]

You guys that are, or have run a coil over front ends ; if I go to 250# springs on the front , I`ll have to adjust the lower spring threaded nuts up higher to get the same ride height correct ?/
I have gone down to 350 # springs from 500 # springs that came w/ my front end.
I have "no" front end lift at all, and am thinking it`s still too stiff, altho it rides a little better that before.
I have the darn nuts ran up about 2 1/2" now , the springs are only 10" springs to start with ! No room with my set up to go to a 12'' shock and spring either !
440/505 727, 3;73 GEARED DANA 60 , 3270 POUND , 68 BARRACUDA, MASSIVE TRACTION PROBLEMS , W/ 10"X 29" STICKY TIRES .
ALL OPINIONS ARE WELCOME , GOOD OR BAD !!-------Thanks, Bob

 

[Garry in AZ]

Yes, if you go to lighter springs, you'll have to readjust or accept the lower ride height. However, a lighter weight spring with added preload will allow the chassis to react quicker. You just have to be careful and not get the springs so light that they will bottom easily.
Have you considered adjustable shocks? If you are able to reduce the rebound damping of the front shocks, the front will lift quicker and transfer some weight. I use Viking or Strange double adjustables and they work well. I hear good things about QA1 as well.

 

[HemiDenny]

regardless of spring length, Qa1 recommends the spring collapse 25%-33% at installed height.

For your 10" spring , that would mean the spring should be collapsing anywhere from approx 6-3/4" or 33% to 7-1/2" or 25% installed with the car at your desired ride height. On a drag car, the lighter spring (one that would collapse to 6-3/4") at your desired ride height) is often preferred because of the stored energy, similar to the stored energy of a wound up 6 cyl torsion bar.

if your 10" spring is collapsing to 6" to get your car to your desired ride height.....it is too soft.
if your 10" spring is collapsing to 9" to get your car to the desired ride height.....it is too stiff.

make sure the suspension goes up/down smoothly with little resistance without the shock....BEFORE the shock is installed.

On a street car where a level ride height is desired, I rarely find the two pre-load adjusters set the same. Usually the passenger side is wound further up due to the offset weight of the offset (approx 1-1/4") drive line.

you did not mention if you have double / separate adjustable rebound and compression shocks.....and where you have the settings selected to.

 

[famous bob]

regardless of spring length, Qa1 recommends the spring collapse 25%-33% at installed height.

For your 10" spring , that would mean the spring should be collapsing anywhere from approx 6-3/4" or 33% to 7-1/2" or 25% installed with the car at your desired ride height. On a drag car, the lighter spring (one that would collapse to 6-3/4") at your desired ride height) is often preferred because of the stored energy, similar to the stored energy of a wound up 6 cyl torsion bar.

if your 10" spring is collapsing to 6" to get your car to your desired ride height.....it is too soft.
if your 10" spring is collapsing to 9" to get your car to the desired ride height.....it is too stiff.

make sure the suspension goes up/down smoothly with little resistance without the shock....BEFORE the shock is installed.

On a street car where a level ride height is desired, I rarely find the two pre-load adjusters set the same. Usually the passenger side is wound further up due to the offset weight of the offset (approx 1-1/4") drive line.

you did not mention if you have double / separate adjustable rebound and compression shocks.....and where you have the settings selected to.

Appreciate the two replies . COIL OVER springs cant be installed w/o the shocks
! Have the shocks set in the softest setting/single adj. .
I figured the stored energy thing the same way/need to keep my ride height the same or a hair higher, lowering it seems to change my front end settings. On top of that, the only front end guy I know , that really knows what he`s doing , has retired !! Not really wanting to change shocks / mostly street car.
Going to try 250# springs. thanks again!

 

[HemiDenny]

Maybe I was not clear. I test the suspension movement to verify nothing is binding without a shock or spring in place.(no wheel / tire attached to the hub)

That is also a good time to adjust the bump stops to make sure the suspension is not hanging on the shock when in rebound and the suspension is not bottoming out the shock on compression.

Do you have spherical or poly busing on your shocks.? Due to the upper and lower control arms swing in different arcs, I often see binding or shock body / coil spring interference with the poly ends.

I would suggest double adjustable shocks for most drag racing....for those that want suspension travel, the double adjustable makes it easier to adjust the suspension for little resistance when for rise when accelerating and keep it there so it doesn't have the pogo effect. Coil over or not.

Single adjustable for a street car for ease and affordability.

The big question is....What is the compressed length of your 10" coil spring at your desired ride height...with the car on the ground and all the weight on it?

 

[famous bob]

Maybe I was not clear. I test the suspension movement to verify nothing is binding without a shock or spring in place.(no wheel / tire attached to the hub)

That is also a good time to adjust the bump stops to make sure the suspension is not hanging on the shock when in rebound and the suspension is not bottoming out the shock on compression.

Do you have spherical or poly busing on your shocks.? Due to the upper and lower control arms swing in different arcs, I often see binding or shock body / coil spring interference with the poly ends.

I would suggest double adjustable shocks for most drag racing....for those that want suspension travel, the double adjustable makes it easier to adjust the suspension for little resistance when for rise when accelerating and keep it there so it doesn't have the pogo effect. Coil over or not.

Single adjustable for a street car for ease and affordability.

The big question is....What is the compressed length of your 10" coil spring at your desired ride height...with the car on the ground and all the weight on it?

HEIM JOINTS on bottom of shocks/complete aftermarket front end, no bump stops. Shocks are all that are holding the car up.
Don't know off hand what the compressed length is ------

 

[HemiDenny]

from your description, my guess is something is binding your suspension.

another issue to look at....I have found front ends bound up because the owner tried to put so much caster in with factory upper bushings and the cam adjusters opposite of one another, it caused the UCA to bind. The movement test without the shock in place (jack holding up car) will answer this.

Examine the shock.... with the shock out and now a jack holding the car up, you can check suspension movement without the shock. With the spring removed and the shock on the softest setting....does the shock move up / down as it should? Does changing the settings make any noticeable difference?

I recommend spherical / heim style ends on top and bottom. Does the shock body show any kind of clearance / interference with the coil spring? Is the shaft of the shock bent?.... seen all three issues with poly ends on shaft.

 

[famous bob]

from your description, my quess is something is binding your suspension.

another issue to look at....I have found front ends bound up because the owner tried to put so much caster in with the cam adjusters opposite of one another, it caused the UCA to bind. The test without the shock in place (jack holding up car) will answer this.

Examine the shock...you might need a jack to hold the car up when the shock is out. Once the shock is out and a jack is holding the car up, you can check suspension movement without the shock.

I recommend spherical / heim style ends on top and bottom. Does the shock body show any kind of clearance / interference with the coil spring? Is the shaft of the shock bent?.... seen all three issues with poly ends on shaft.

without spring, on softest setting does the shock move up and down fairly easily?

Will check that stuff, already ordered 250# springs and thrust washers for them.