Spring rates
 

For 96-00 Civics (EJ6-8 and EM1 chassis codes)
96-00 EX - 165F/80R (P/P)
99-00 Si (EM1) - 201F/99.8R (P/P)
97, 00-01 ITR - 250F/250R (L/P)
GS-R - 200F/95R (P/P)
CTR - 240/240 (L/P)

H&R OE - 280F/190R (P/P)
Eibach ProKit - 290F/190R (P/P)
H&R Sport - 330F/280R (P/P)
Eibach Sportline - 310F/275R (P/P)
Gold-line GL 2.5" drop - 320/190 (P/P)
Gold-line GPS 1.25" drop - 275/160 (P/P)
Koni RSK Suspension kit - 154-205/270 (P/L)
Neuspeed SofSports - 260F/150R (P/P)
Neuspeed Sport - 280F/180R (P/P)
Neuspeed Race - 485F/395R
Skunk Coilovers -old - 400F/300R (L/L) for civic, 500F/400R for integra
Skunk2 Coilovers - new - 500F/400r (L/L)
Spoon Full Coilovers - 300/240
Progress Coilovers - 350F/250R (P/P)
Progress Lowering Springs - 320F/200R (P/P)
Ground Control Coilover - 380F/280R (P/P) (this is the standard kit and the springs are mildly progressive).
Tein RA/RE/RS - 783F/559R (L/L)
Tein HT - 1119F/448R (L/L)
Tein HG - 365F/129-196R (L/P)
Tein SS - 448F/224R
Tein Flex - 504F/280R
Tein S. Tech - 235F/140R
Tokico Illumina Kit - 250/123 (P/P)
APEX'i WS - 447f/178r
Suspension Techniques - needed
SSR Cup - 392/280
SSR S1 - 448/448
JIC FLT-A2s - USDM - 504F/336R (L/L)
Sparco - needed

For 02+ Civic Si (EP3): ~ Very special thanks to Mike (EXavier) for these!!!
Progress - 280F/500R
Eibach Pro-Kit- 15-20% stiffer then stock
Eibach Sportlines - 20-25% stiffer then stock
Sprint - 20-25% more then stock
H&R Sport - 25-30% more then stock
Tein SS - 336F/448R
Tein Flex - 448F/559R
Tein S. Tech - 157F/291R
We are really in need of finding out what stock rates are for an EP Hatch!!!

If you've got any to add or have springs for me to test let me know and I'll put them on the compression tested and do a full plot of the springs. I'll need one front and one rear spring to test them.

P = Progressive
L = Linear