The differential carriers in Spartan Racing's past have had some significant issues in reliability and manufacturability. The senior project team for this year decided to improve upon the designs of previous years to prevent any chances of the system being the cause of a failure during competition. I chose to take up the part requiring more of a redesign: the differential carriers.

As the name implies, the differential carriers are responsible for holding the vehicle's differential in place. The carriers must be able to withstand the 2 tons of chain tension produced during a sudden launch event while also complying with rules, remaining manufacturable, and allowing for serviceability. Integration with other systems such as suspension, chassis, and exhaust are also important factors to consider.

In order to design new carriers that are strong enough to survive the immense loads of the engine, a load case had to be developed. I took into account the tractive force (tire grip), shift/launch impulse loading, and inertial component resistance into the total load produced by the engine. The total ended up being about 14,000 in-lbs of torque on the rear, rotating components (compared to previous years' 13,500 in-lbs). This load was applied in the direction of the chain on the carriers in all FEAs.

Using these loads, I went through different concepts and ideas. I fleshed out the final concept and in the end, the team ended up with a hopefully more reliable design. The manufacturability of the new design has already been proven as our manufacturing sponsor was fed up with the complexity of previous years' design. He quickly changed his mind and agreed to manufacture the new parts once he saw they were much simpler to make.