What spring rate did you install?

 

 

did you mess up the preload?

 

I just looked up the spring rates on the manufacturer website and they list front/rear as 14k/12k. That's 784/672 lbs, my revised 350Z spring is are 314/427 which is firm but has good ride quality, my previous Nismo S-tune was 448/504 and they were definitely FIRM.

I don't even think I could drive a car with 784/672 on the street, those are track springs only.

 

OP this may come across as harsh but it's not intended that way. You obviously didn't do enough research before you bought your coils. For a major purchase like this that's a big mistake, and it seems you don't know much about them....

Spring rate is not how loose or tight they sit, each set of springs has "spring rate" that reveals how soft or stiff they are. The higher the rate the stiffer the spring and no amount of "loosening" them is going to make them softer. Your coils probably have a dampening function that will make the shock stiffer or softer, this will affect in a major way how the car rides. You admitted you didn't know that you needed adjustable rear control arms but if you're lowered an inch or more you're going to need adjustable upper front control arms that can also adjust toe and rear camber arms/toe bolts. If you don't spend the money on those you'll eat up tires at an astonishing rate which will in the long run cost you a crapton of money.

Before you drive your car any significant mileage research how to successfully use coilovers, they can be one of the coolest mods when done correctly but incorrectly they will be a daily nightmare and your car deserves better than that.

 

14k/12k holy backpain batman

 

"These are a great coilovers for the street and track use. Provides a comfortable ride while improving handling."