b'GM F/X TRACK-RSXEasy Caster Tuning Upper Control Arms: o1 Thick Tube DOM Upper Control Arms oGreaseable Steel Pivot Shafts for Long Life oSlotted Shaft & Offset Slugs Made it Easy toSet Caster for Your Setup StrategyTech Tip 14: Achieving the optimum (fullest) contactpatch of both front tires, dynamically in full dive, roll, steering & braking in the corner, is an important key to a fast race car. This is not easy, with a lot of factors affecting the final contact patch. Wheel load, tire roll, chassis roll,camber setting & gain, caster setting & gain, spindle KPI,steering angle, etc., all affect the final contact patch.The combination of all these factors, minus wheel load & tire roll, is called dynamic camber. Over four decadesRon has learned the dynamic camber needed to achieveoptimum contact patches on both front tires on vehicleswith a range of weights, varied tire designs, differentsidewall heights & wheel-width-to-tire-width ratios.Some basic things to know are:Camber helps the outside tire & hurts the inside tireKPI helps the inside tire & hurts the outside tireCaster helps both the inside & outside tireWhen are 5 or 8 KPI spindles better? It has to do with the travel & roll angle of the suspension strategy. When Ron works out a suspension & steering geometry setup, he utilizes a 3D suspension software that allows him to look at the tire contact patches when the car is in dynamic dive & roll. Like the illustration to the right.Then he works with both static & dynamic camber & caster, as well as the spindle KPI to achieve optimum contact patches for both front tires. Utilizing 5 spindles helps Ultra High Travel/Low-Roll setups achieve optimum tire contact patch. The 8 spindles work better with Moderate Travel/Moderate-Roll setups to achieve optimum tire contact patch.911'