i drive a 2014 lexus is250 non f sport and im on BC Racing BR Type coils. Im experiencing knocking noises when im trying to lower my rears. I can't go lower than 4 inches to not encounter this noise. Am I the only one with this problem??

 

Is the "knocking" caused by bumps bottoming out the tire against the wheel well or is it a clunking when going over small bumps and or when turning? If the former, you're too low. If the later, you need to check your preload on your rear coils. You should loosen the spring seat and then hand tighten up to where it's tight against the spring. Then move the spring seat lock up to the spring seat nut. Now tighten the spring seat nut until you can fit the handle of the wrench between the two nuts. Then tighten the spring seat lock nut.

 

i am no where close to bottoming out or being too low, im like maxed high on the ride height. If i go lower passed 4 inches its just clucks as im driving. Nothing doesnt even look wrong

 

Can you provide some photos of your shocks and springs installed so we can take a look and maybe spot something out of place?

 

How long have you had the coilovers on? Recheck everything that was bolted back up along with the torque specifications. My guess something is not seated correctly and/or loose. Its possible that you are not adjusting the coilovers correctly also. I only have experience with Tein coilovers, and you don't adjust the spring tension on them.