[socalwrench]

ALL the REPUTABLE SPRING RATES and LOWERING HEIGHTS are on this thread. This way I, and many others, can make an informed decision. It is my understanding that the FR500 springs use a modified design and wouldn't apply to the typical street car- such as a full coilover setup. This thread excludes full bodied coilovers.

Thanks to SteedaGus and F1Fan (Chip) for helping complete this information.

As of September 2009:
Name- (part number)- lowering amount- spring rates

Stock/Factory GT springs (Tags= Yellow, Orange) - front: 136lb/in / rear: 142lb/in

Eibach Pro-kit (pn 35101.140) / Ford Racing (K-springs) (pn M-5300-K) 1.5/1.7 - both variable front: 173-248lb/in / rear: 195-236lb/in

Eibach Sportline (pn 4.10135) 1.6/2.0 - UNKNOWN (*tested by Chip- reportedly very high)

Steeda Ultra-lite (pn 555-8206) 1.25/1.5 front: 195lb/in / rear: 175lb/in

Steeda Sport (pn 555-8216) 1.0/1.25 - front: 200lb/in / rear: 175lb/in

Steeda Competition (pn 555-8241) 1.0/1.25 - front: 225lb/in / rear: 185lb/in

H&R Sport (pn 51655) 1.0/.75 - UNKNOWN

H&R Super Sport (pn 51655-77) 1.7/1.9 - both variable (working rates) front: ~250lb/in / rear: ~200lb/in

H&R Race (pn 51655-88) 1.5/1.4 - both variable (working rates) front: ~300lb/in / rear: ~275lb/in

Roush Performance {sold in pairs} (pn 401294 and 401295) 1.0/1.0 - UNKNOWN

Roush Extreme (pn 402331) 1.0/1.25 - UNKNOWN

Tein H-tech (pn SKG12-BUB00) 0.94/1.65 - front: 163lb/in / rear: 163lb/in

Tein S-tech (pn SKG12-AUB00) 1.5/2.24 - front: 174lb/in / rear: 174lb/in

Vogtland (pn 950084) 1.3/1.3 - variable front: 160-240lb/in / variable rear: 120-220lb/in

Saleen/Racecraft (pn 10-1302-B12999) 1.25/1.25 - UNKNOWN

Sprint (pn 2115) 1.6/1.5 - UNKNOWN

BMR Fabrication Inc. (pn SP009) 1.25/1.5 - variable front: 120-165lb/in / linear rear: 140lb/in

*NOMINATED STICKY*

CHECK OUT PAGE 4 - post #33 - FOR MORE ACTUAL TEST DATA