This study aimed at the characterization and validation of a drum-brake spider with mass reduction, using a new concept of a nanostructured ductile cast iron alloy. There is a well-known effort in developing lighter, more competitive products with higher safety and longer service life for brake systems. One of the approaches that enables this type of development is the use of new materials capable of delivering superior performance. Conventional ductile cast iron alloys used in brake spiders exhibit limited mechanical properties, which restricts mass reduction while still ensuring high durability in service. One way to obtain high-performance ductile cast iron alloys is through heat treatments such as austempering (ADI), which provides significant gains in mechanical strength but involves high cost and environmental liabilities due to the use of salt baths. The modified and nanostructured ductile cast iron alloy proposed in this work exhibited mechanical properties in the as-cast condition that meet the standards for ADI-treated ductile irons, showing an increase of 102% in tensile strength and 78% in yield strength compared to the baseline spider. Based on this new material, a topology optimization was performed on the baseline spider model, resulting in an optimized design with a 40% mass reduction. The model was validated using casting simulation software, and tooling was manufactured for producing the new optimized spider samples in the nanostructured ductile cast iron alloy. Static mechanical properties and microstructure were determined and approved, allowing the fatigue testing phase to proceed. Initially, the spider samples were instrumented with electrical strain gauges and subjected to the standard structural bench test known as the Chuker test, which can simulate real operating conditions of the brake system. Considering that this test requires extended bench time, an accelerated durability test was developed for the new spider model using three servo-controlled hydraulic cylinders, based on the stress levels obtained. The results from the accelerated durability bench test demonstrated superior fatigue life for the optimized spider compared to the baseline model, also validating the new testing procedure.