RS4 FJ40 chassis

Starting with Roadster Shop’s proven laser rails, a complete chassis was engineered utilizing the best components available in the industry.  HD Ford 9" front and HD Ford HI Pinion 9" Rear differentials are tied into the chassis through triangulated 4 links designed to optimize anti-dive, anti-squat, and suspension articulation.  Massive sealed x-Axis flex joints allow increased misalignment, longevity, and performance over commonly used spherical and Johnny joints.  Fox Racing 2.5 Factory Race Series coilovers tuned with RS specific valving offer the best of both ride quality on road and off-road performance.  CAD optimized front steering geometry eliminates bump steer entirely while laterally controlling the axle. Massive 5”x2.5” .188 wall frame rails provide significant strength gains over the undersized stock chassis. Popular classic and modern engine and transmission combinations have standard mounting provisions available.  All original mounting locations have been engineered into the RS4 chassis to allow easy bolt on installation with zero cutting to your body.  Ride height has been optimized eliminating the need for body lifts. Splined front and rear sway bars and Fox Bump stops are optional along with a long list of engineered options to help assist and expedite your build.