b'FORD RACE-STAR AIXHotchkis Heavy Duty Road Race CrossmemberoHeavy Duty Thick Wall DOM Tubing / MIG Welded oTrick Slant Top Bosses Provide Easy Access & Optimum Strength oThis Crossmember Ties the Frame & Lower Control Arm Mounts Together oEliminates Flex Under the Hard G-Force Loads Created by the Grip of This Suspension oKeeps the Geometry True & the Handling ConsistentoSlotted to Allow Full Adjustment on Lower Control ArmsTech Tip 20: The shock Motion Ratio (MR) of yourlower control arms play two important roles. First isunderstanding the higher the motion ratio the bettercontrol your shocks will have over the suspensioncreating more grip. On the lower control arm (LCA), the closer the shockmounts out toward the wheel, the less leverage the LCAhas over the shock & the more control the shock has over the wheel. Shock control is good for grip.Being out closer to the wheel, the shock can respond quicker, which allows the shock to keep the tire & wheel loaded over the undulations of the track surface a higher percentage of time. Plus, the shock travel is closer to wheel travel providing better valving control.Second is figuring out what spring rates you need to achieve your target wheel rates. The raw MR formula is BC = MR. For example, a 16 control arm (C) with the shock mount (B) at 12 = .75 MR (Raw) To get your final motion ratio, we take the raw MR, square it, then multiply by the Cosine (CoS) factor for the shock angle. The Cosine factor varies with the shock angle, but for an example shock angle of 15 the CoS is .966.Carrying on with our raw MR of .75 example, the formula would be .75 x .75 x .966 = .543 final motion ratio. So, if we want a 300# wheel rate, we take 300#.543and figure out we need 552# springs. So, we pick 550# springs & live happily ever after in Victory Circle.All RSRT & Speedtech Extreme Lower Control Arms have been designed with high motion ratios for better shock control & grip!1085'