need advise on tuneing rear shock/springs

[LowBuckX]

Got the Nova on the road today with some problems. I have QA1 single adjustables on my 3 link running 200# spring mounted at a 20* angle. (175 ish corrected) Im set at 4 clicks from full soft. I have no bind in the links . With no springs on the shocks i could articulate the axle like a rock crawler by hand with no bind.

My issue right now is the rear is way to stiff. Would this be fault of shock setting or spring rate or both in combo? I will put it at full soft tomorrow and see but would like your opinion.

And front Hotchkis springs are very noisy creeking and groaning. Ive put up with this for a while but today they popped and graoned going up a curb into my driveway...... Why are the Hotchkis springs so noisy?

[ArtosDracon]

Few things we need to know. What is the total weight of your car? What is the AS of your rear suspension? What is the weight bias of your car? And how high is the COG? Are you sure it's the springs causing the noise in the front, sounds more like dry poly bushings that are binding.

[dhutton]

There is a pdf here that tells you how to calculate the correct spring rate. I used it with good results.

https://www.pro-touring.com/forum/showthread.php?t=69444&page=2

How much preload do you have in your springs? Are your shocks reasonably well centered in their travel at ride height. Should be 50/50 or 60/40 according to the pdf.

[LowBuckX]

I have very little preload in the springs. I See pics of other peoples setups and thought it was odd they have there spring adjusters adjusted up at least double what mine is. IE more threaded body showing.

Shock travel was set at 4inches bump 3 droop.

I have no access to scales. So im just used a generic cog figure that I found for a simular car that follows Herb Adams suggested COG figure of which I dont have handy

[Roadbuster]

Lowbuck,
Lower the compression setting on your rear shocks and see if that helps. I have 175 lb rear springs (stock location) and had to run the shocks surprisingly soft. Without the shocks in there I could bounce the car like a basketball with one hand. With them installed the car barely moves.

The creaking and groaning up front sounds like poly as a previous poster mentioned.

Good luck! Let us know how everything is working out and pics please!

[MrQuick]

You are just going to have t experiment with ajustments and different spring lbs.

Check your front spring and make sure its in the pockets correctly, anso look for any spring to subframe contact.

Vince

[LowBuckX]

its so dam hot outside its gonna have to wait till later to play. Im now thinking the poly bushings also. Will have to make some del-a-lum type this winter.

[LowBuckX]

Well I would have bet $50 an hour ago that these shocks at 4 clicks from full soft wouldnt be the problem but now I have them at full soft and I have to pree load the springs more because after adjusting the nob and jounceing the car the body is now 1/2" lower at the wheel arch... time to get anti seize everywhere...

[LowBuckX]

Final numbers


Anti-Squat40.44%
Roll Axis Angle0.00degrees ( - roll understeer, + roll oversteer)
Roll Center Height9.00in
Instant Center X-Axis102.00in
Instant Center Z-Axis8.25in

[ArtosDracon]

Congrats on the 0 degree roll axis! Without rough weight it's impossible to guess the right springrate.

If your car settled 1/2" from adjusting the shocks to a softer compression setting, I would say they just hadn't settled since new yet.

I would say pre-load them back up to your ride height and leave them on full soft, drive them around and increase compression as needed.