Quote:

Looking at a Road Race application on a 1968 Barracuda.…

Spring package:

350 lbs/in calculated at the ball joint wheel rate front springs (1.14” t-bars). 1.25” hollow sway bar

140 lbs/in rear leaf springs (sort of guessing at that). 3/4 “ sway bar that is adjustable

Computer wheel weight scale sheet as follows:

LF..987 RF..924
LR..731 RR..770

56% front weight bias

108 wheel base

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Should I be looking at progressive, digressive, or linear shocks?

What kind of shock rates should I be looking at to control those springs in this application?

Do I need to get more info to make a better choice? If so what?



We have seen positive results in applying linear valving in autocross applications. The harder you charge the corners, the sticker the tires and the heavier the car, the more you will find the linear stuff to your liking...

As far as shock rates go, the variables are vast. Shock rates go up as shock speed increases. (On the shock dyno, if you run the shock at 6 inches per second, record the dampening rate, then spin that shock at 10 IPS, the shock will be stiffer given the same valving or setting). The shock rate does work to control the springs but also helps to control body roll...The higher the center of gravity, the harder you drive, tigher the corners etc, the stiffer the shocks need to be...

In your case, adjustable shocks would be a wise investment. One idea is to tune the shocks to your liking-performance is maximized and then getting the shocks dynoed. From there, you will have a baseline. Two things come from this exercise. One, you now have a file of each shock in case of damage and need for repair. Two, you can map where you are, see how much a click change makes in pounds of force (in the shock)and get an idea of how much the shock change will help you dial in the chassis. Gotta know how much to change something. Also, this could reduce the risk of tuning past the sweet spot when making a guess without hard data to support the tuning choice.