Adjustable shocks from Hall

cab,

the springs will not be long enough when the suspension is fully extended. The "Hyperco" springs installed on my Pantera are secured to the upper spring retainer of the Koni shocks with cable ties. When the car is jacked up, the other end of the spring is inches away from the other spring seat, so the spring is loose as you describe. Once resting on the ground, the springs are not "loose" or free to rattle around.

your friend on the PIBB, George

I have never seen a suspension that had the situation where the spring didn't have a preload in full rebound. You have never had a problem with this? I don't plan on going airborn but am a bit concerned about this under a pot hole or such.

I agree with you Cab. It should have some pre-load on the springs. This means the springs are not sized properly for the application. The spring rate and spring length are not correct for the car. There is a lot of info on the web about springs. You may want to look at this web site for more info.

http://www.stockcarproducts.com/spgtech.htm

Thanks all for your help. One last thing, I still have the coils from before. They were on a set of Koni shocks so I am not sure if they are original equipment, but do you know if they would fit the Hall shocks. Those springs are about 5 inches longer at no load.

I've had no problem whatsoever. The last time I went air born, Dukes of Hazard style, I landed just fine

I have seen autos and motorcycles with springs that are "too short" when the vehicle is off the ground. Now my qustion to Scott is, why "should" there be pre load on the springs when the suspension is fully extended?

The reality of the situation is, you are lowering the car from its original ride height, running higher rate springs at the same time. If anything, its not that the springs are too short, its that the shock travel is too long.

I'll guarantee you this much, Gary Hall did not select those springs by throwing a dart at a catalog, he consulted somebody with expertise in that area.

your friend on the PIBB, George

Thanks George,I am sure that Gary did his homework. I just have never seen this set up, and I have been working on supensions for 16 years, although most of it on trucks. Problems with the suspension going no load is that your spings will hammar on the sping seat when it comes back down. Also on any suspension to many DOF results in problems. As an example if your ball joints do not have any parisitic drag, torque, you develop steering shimmy and shake. The drag limits the DOF, and as a gut feel it would seem that the preload would help limit this type of situation.