Whats the hardest spring that can fit CRT?

[lutach]

Originally Posted by superek4

so the mugen red springs are the hardest?

I have the Reckward Tuning Extra hard, the blue Mugen, but the red one is harder and it's what I've been using. If you feel that your spring is not hard enough, just preload it to the way you want, but sometimes your vehicle will bounce too much and thicker oil should be used.