Difference in FMS "B" and "C" springs?

I just ordered a set of H&R springs for my car. Are they progressive? I've got lowering springs on my car now, but they came on there so I don't know which brand they are or how much the car is lowered...but I do know the ride quality blows. I was going to go with Steeda or Eibach but everybody kept recommending H&R so I went with them. Hope I'm happy with the results!
 
I have the C-springs and I really like them, you will not feel every little bump like I did with Eibachs. I highly recommend the C-spring, actual drop was closer to 1.5 inches all the way around. They claim they are not progressive, but a week later I could see a slight difference. Handling is great, alot better, and that is with stock susp...can't wait to do shocks/struts, LCA and UCAs!!!
 
S/CBlack95GT said:
Progressive just means that the spring has a variable rate. For example, a progressive 425/535 spring is rated at 425lbs for the first inch of compression then 535lbs once the spring is compressed past one inch.

Close, I found this definition online to explain it better.

Progressive-rate spring- A spring with an increasing spring constant. For example, if the first inch of spring motion requires 425 pounds of force, the second inch would require more than an additional 425 pounds, and the third inch would require still more. Progressive-rate springs become stiffer as they are compressed, unlike single-rate springs, which have a fixed spring rate.

the numbers were changed to fit the example better
 
I've had both on my car, B's first and now C's. I greatly prefer the C springs. The B's made the car feel almost soggy yet harsh. The C's, in concert with 03 Cobra Bilsteins, seem to offer a much more solid feel all around.

Also, with the B springs, -1.4 degrees of camber was a positive as I could get it. With the C's, I have it at -0.6, but I have a full range of adjustment.
 
Mrgreen94gt said:
Also, with the B springs, -1.4 degrees of camber was a positive as I could get it. With the C's, I have it at -0.6, but I have a full range of adjustment.

Thats odd. With my Bs and MM C/C plates I could move mine from about 0 degrees to a negative 1.5, with the plates in the positive orientation. With the plates swapped side to side and in the negative orientation they will move from a negative 1.0 to a negative 2.5 degrees.
 
S/CBlack95GT said:
Thats odd. With my Bs and MM C/C plates I could move mine from about 0 degrees to a negative 1.5, with the plates in the positive orientation. With the plates swapped side to side and in the negative orientation they will move from a negative 1.0 to a negative 2.5 degrees.

I guess it all comes down to variation among cars and mine being a convt. might have something to do with it. There may have been some plate installation issues as well, the first time around. :shrug:

I don't think the fact that you have M/M plates and I have the Pro3i ones would make much difference in this area, but it may.