Spring Rates

[RET_COP]

Infletcher and Wayne
Ok here is some more information. I've had to really push the brake pedal hard to get the car to stop. No fade or anything,as a matter of fact a hard pedal and close to the top. I had a 1 1/8 bore MC Ford oem. I figured through this forum that my line pressure was inadequate, probably 475lbs or so, and I needed about 700 or more. I called master power brakes and they said whach out for the GM metric low drag as the piston retracts more in the bore (to eliminate rotor contact) and therefore will require alot of fluid volume to get the piston back in contact with the rotor. It works good with the 1 1/8 bore except of the low line pressure. GM had a warning out and had a different MC made for the situation.
Wilwood said I would need a 7/8 bore MC to get in the area of 700+ lbs.
Ok so I bought and installed the tandem M/C and went out for a test. I felt the line pressure and the car stopped much better except for the fact that the pedal went almost to the floor. It did not fade and it held at that low position, but it takes getting use to to say the least and a bit scary. I researched this and found out that a mid 70s [nova, camaro chevelle]intermediate 5.5" bolt space caliper would work,as this was not a low drag caliper. I opted for the direct replacement from Wilwood (D-154) I will let you know how it works.
Wayne, MT s/t are close to the cooper cobras, the s/r are a high performance, sticky directional tire with a little more sidewall flex. I beat a new dodge charger off a traffic light (just first gear) and the tire hardly spun. It was a costly mistake on my part on the purchase but hey it happens. I'm looking to get 450.00 for them. I paid 800.00. I also now need wider rear wheels. Does it ever end.