At 08:51 AM 2/2/01 -0600, Patrick Washburn wrote:
>Thanks for the info guys. Perhaps the cumalitive wisdom of the CM list can
>help me with the valving. What is the general set up philosophy with an
>FF? Stiffer? Softer? How does the re-valving relate to spring rates?
>What works? I don't need anyone to give away their "trade secrets", but I
>would appreciate a general lesson in what works for AX. (If you *want* to
>send me your specific set up data including alignment, you can be assured
>that it will remain a secret with me!)
Pat,
I assume that you now own an 84 Reynard FF. Congrats! Tell us more about
the car!
For set up info and theory I suggest that you start by spending about 100
quality hours reading through FF Underground
http://server5.ezboard.com/bformulafordunderground for the last year and a
half:-)
Stiff vs. Soft: It seems like every possible set up works for somebody.
Just like gearing and fuel and tire brand:-)
Wheel rates close to corner weights have been known to work decently with
Konis. However, with the OEM Bilsteins I had success with wheel rates
ranging from 1/4 to 1/2 the corner weights. The softer the springs, the
more you need Silasto bump rubbers to keep the floor off the ground.
Bilstein sell silasto for their shocks (Konis have a different shaft size I
think).
If you stay with the Bilsteins, hopefully one of the Reynard guys can give
you a clue what valving to use.
However, one suggestion: in a FF used for autocrossing, "too soft for the
spring rate is probably much less of a disadvantage than too stiff".
Remember, in general you don't need to compensate for other suspension
limitations with shocks like the folks in Stock or Street Prepared need to
do. Remember also, that these are real RACING Bilsteins so they are already
valved for racing, not for street.
As for alignment, it depends on tire brand. For Hoosiers, my experience is
that you just need to be "in the ballpark". Too much or too little camber
just causes excess tire wear on the involved edge and tends to make the
tires "go off" sooner. You can see the "distress" if you have too
much/little camber.
Rear toe is easy: about 1/16 in per wheel is a good starting point.
Front toe depends on ackermann. I have 100 percent ackermann so I run a
1/16 or so toe out per wheel.
The absolutely most important setup variable is adjusting the nut behind
the wheel. Practice . . . a lot! Remember also that tire temps and age
effect both grip and balance. So do course conditions. Car setup is only
one factor in how the car handles on a given day or even run. As an
experiment, go to a practice event and don't change even one thing between
runs other than making sure the tire pressures are the same at the start of
each run. You will be amazed at how different the car feels sometimes on
different runs . . . especially when you are new to it. This is even more
true in the spring when the pavement temp changes a lot during the day.
My motto is that a slow run is never the car's fault!
Dick Rasmussen
CM 85
85 Van Diemen RF-85 Formula Ford
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