Front Beam Spring Tension

[fvee62]

I am trying to figure out the optimum front spring tension on my Protoform. Right now I have so much tension that the front (Penske) shocks are holding the front end down to a 3 "ride height measured at the skid plate. If the Penske's are detached the chassis springs up a great deal. The Penske's don't have much travel (compared to the Adco shocks on my D-13) and I am guessing that they are supposed to be that way to hold the front end down to produce a more "aero" body attitude at all times .
With me in the car (185 lbs.) the front shocks do not compress at all. Also, I have an adjustable front beam.
Anyway, I was hoping tor some rule-of-thumb guidance on how to proceed to get the front end in the ballpark.

[pacratt]

If you're not running an adjustable beam, you'll have to pre-twist the spring pack.
Glenn

[FVRacer21]

Greg,

You should be at or close to the 3" ride height with no shocks.

Before you go too far, some questions:

Is this a new spring pack or used spring pack?
If a used spring pack, is is installed upside down?
If a new spring pack, is it made up of solid bars, split bars or combination? and what is the total # of bar "levels" (I believe 6 or 8 )

If you do not have a spring adjuster in the beam you should consider one - contact VSR or Advantage for more info. From what I remember there is a different rate if the spring is in the top or bottom tube, but the location of the adjuster may dictate that.

If you decide to go the overbending spring way - you may want to find the ideal spring rate. This might involve the ratio of solid to split bars (leaves) and or cutting (splitting in sections) some of the bars. If someone has a Protoform they can jump in with what they use.

If you decide to overbend, here is the technique I used. (spring in upper tube)

https://www.youtube.com/watch?v=BNhQkxL29Fk

This came from some old Lynx instructions from many years ago and the dimensions may not be the same for your car.

Good luck,

ChrisZ

[problemchild]

Use your RH adjuster to set your ride height at 3" with shocks not attached and driver in the car.
Reattach your shocks and go. If the car is too low and hitting the ground, then you can raise it until it stops dragging.

By droop controlling the front, as you are, you are effecting the car handling significantly. Controlling the front droop effects weight transfer laterally and longitudinally. Front droop control tends to make the car more crisp in turn-in. If you lengthen your front shocks (by removing internal spacers) then the car will roll more and give you a feel much more like your D-13 with Adcos. It probably won't generate as much grip but you may be more comfortable driving it.

[fvee62]

Pacratt,Greg & Chris -Thanks for the input, I think I have a good idea on how to proceed now. I appreciate the advice.
Greg D.

[BLS]

I would think you have three problems to consider, spring rate, ride height, and preload.

I assume by "adjustable beam" you mean you have a beam with a ride height adjuster.

As mentioned, the ride height should be adjusted with the shocks disconnected and you in the car.
If the car must be pushed down in the front to connect the shock then you have some amount of preload.
The only way to change your spring rate is to modify the torsion leaves, or change the length by using twin adjusters (shortening increases the rate).