Well I have progressed my testing and research on spring rates and heights (Thanks to Paul for his help as well) and I thought I would share it with all you helpful chaps...
I am still testing springs and looking for any additional information especially actuall ride heights rather than quoted !
Please let me know the measurement from each wheel centre to the arch lip directly above the wheel centre front and rear (This eliminates to some extent different wheel and tyre combinations). I would be interested in standard figures as well as other springs.
Front rate lb/inch rear rate lb/inch
Standard F-100(100 measured) R-300 (294 measured)
Eibach F-114 R-263- 325 progressive
ML trackmeister F-yet to measure R-205 measured
H&R F-180 R-340
Spax F-100 measured R-Too badly made to measure !
Geoff Steel track F-400 R-300
Regarding ride heights measured from wheel centre to the lip of the arch directly above (in mm):
Standard 1 F-355mm R-337mm
Standard 2 F-345mm R-335mm
ML trackmeister F-330mm R-300mm (With 15mm tops and bottoms, BMW supply 3mm, 5mm and 10mm I used two on top and bottom to raise the rear ride height, it measured 275mm with 5mm top and 10mm bottom. The wheel rate is .54 times the spring rate and hence 10mm of spring spacer should raise the ride height by 18mm but it actually raised it less)
I hope this proves useful, I will update as soon as I get any further info....