Shriker
I think part of the problem is that to go with the GS set-up it will actually cost more. At least the calipers are something like 200 buck each vs. Z06 calipers for $80-90 each.

As far as the bias spring, I wasn't looking for an adjustable set up. Just trying to learn more about the springs. Curiuos if they were all different rates??

 

Personally, I think that if you want to upgrade your brakes with bigger pads, granted 0.2" of an inch smaller disk, abiet 1/4" thicker (which reduces heat by the way) at less cost than the GS stuff, for a marginal (I believe the quote was) improvement in braking, that looks better ... GO FOR IT ! ! !

I seen a few tests of the braking difference, and around 6' @ 60mph, which could be the difference between a busted ride and injury, to being able to stop with an intact vehicle and no injury, it seems to just add up to me.

Granted, my brakes will lock up quicker, and easier, than before (ABS remember), doesn't nose dive, and it means that I don't have to use the brakes as aggressively to stop. Seems to me to be a no brainer.

Johnny - now off the podium - Evans

 

Does anyone know how to calculate changes in
front - rear braking percentage, for this situation?
(I have been trying to collect 'encyclopedia'
info concerning c4, c5, f-bod,,,(brake) piston dias,
M/C pistons, brake bias spring force, etc,, but
with meager results)

 

I don't think that there is a general formula for doing what you want to do, due to the variables involved.
But ...
You will need the friction coefficiency of the tire with a given weight on it - front and rear,
Percentage of weight on the front and rear tires - this will give you a bias, front and rear and left to right
You should figure the shift from rear to front, up to maximum adhesion, during the breaking event.
Friction coefficient of the pads vs disks vs hot or cold operation vs hot or cold, wet or dry temperatures, etc., etc., etc.
All of this will have to be figured in at different temperatures, wet or dry tire/pavement.
And probably half dozen other things that need to be figured into the equation, that will change with different values.

Hence the need for an adjustable proportioning valve, because of the different conditions (pronounced variables) that would be encountered, from morning to afternoon, up and down temps, wet or dry, traction of tires, good turns bad turns.

Buy the spring and be done with it.

If you are going to play the adjust the spring routine, buy stock in a brake fluid company - buy it by the case, hire a support crew and support vehicle - they will need to follow you whenever or where ever you go.
You could buy the modeling software, very very expensive, that would reduce, not eliminate the need for the above.

Not trying to be a smarta$$, just realistic, granted one or all of the above will change the proportioning value (pressure or spring rate) or bias on front to rear braking.

 

I asked earlier in this thread about installing the adapters on my -84 and got this info by email - I thought more people could be interested in this:

The first thing you need to do is open up the clearence holes in the knuckle, to 9/16. Then you will need to machine the surface of the knuckle that mates up to the adapters in order to center the rotor/caliper. My '84 knuckles required .070 to .080. I've been told that there were 3, maybe 4 variations during the build of the '84, the first C4... So this may differ on your car??? The pic's should be pretty clear as to what needs to be done.

Another option, is to just swap out the knuckles for '85 thru '87.