This shock is based on zero point and increasing the zero to increase the the effect the shock has on rebound. We build a series of RFGF's from 200 to 800 at zero depending on your needs. The 500 is a real good shocks and can be used in about every class of racing.
The bottom chart shows how the zero is increased on the rebound side. This shock will help the car turn in and thru the corner and will increase overall speed in the car but will decrease exit drive.