I have to chip in, I drove Adams car with the Mugen SS and I prefer my Eibach's, lol...I have driven all three, OEM, Eibach and Mugen Eibach Pro feel a softer ride straight line over OEM and Mugen, but feels stiffer than stock in corners (and over large bumps!)Mugen SS felt more aggressive than OEM and Eibach.OEM was also pretty stiff but not as aggressive in corners as the Eibach's Plus I didn't go into the gravel like Adam did at Castle Coombe
ha ha.... I found the following info on Mugen vs OEM vs Eibach Spring Rates:
Stock JDM DC5R spring rates: F 3.7k R 7.4kMugen SS spring rates: F 5.0k R 8.2k (Drop = 1.4" lower all round)Eibach Pro-kit (progressive): Spring Rate: (15-20% more than stock) (Drop = 1in Front/1.1in rear) So (if my calculations are correct!) the Eibach Pro is progressive up to the limits which are between: Front 4.25k - 4.4k and Rear 8.5k - 8.8k and isn't as low as the Mugen's which is what me and Adam Noticed between our two cars. There is good reason TGM recommend the FRSU + Eibach combo for the DC5 for the road/track, those guys actually race DC5's in the UK. But at the end of the day it all depends what you want from the car. I wanted Suspension that was softer than OEM straight line on the rubbish UK roads but better on Track than OEM, that's exactly what I got with the Eibach's + FRSU combo. Plus the 20mm or so drop I was after
My Summary:OEM: Japan roads/Track FocusedMugen: Track FocusedEibach: UK roads/Track Focused.